SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
{tag}781028445@
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
{tag}704115727@
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
{tag}781030585@
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
{tag}781033145@
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
{tag}781048020@
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
{tag}704115727@
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
{tag}781030585@
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
{tag}781033145@
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
{tag}781048020@
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
{tag}781028445@
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
{tag}781030585@
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
{tag}781033145@
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
{tag}781048020@
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
{tag}781030585@
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
{tag}781033145@
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
{tag}781036275@
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
{tag}781048020@
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
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COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
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Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
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Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
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COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
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Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
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Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
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Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
{tag}781048020@
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
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Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
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Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
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COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
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CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
{tag}781048020@
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
{tag}704115727@
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
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CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
{tag}781048020@
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
{tag}781028445@
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
{tag}781030585@
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
{tag}781048020@
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
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CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
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Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
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COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
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Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
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COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
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Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
{tag}781028445@
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
{tag}781048020@
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
{tag}781048020@
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
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COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
{tag}781030585@
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
{tag}781033145@
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
{tag}781048020@
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
{tag}704115727@
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
{tag}781030585@
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
{tag}781033145@
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
{tag}781048020@
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
{tag}781028445@
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
{tag}781030585@
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
{tag}781033145@
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
{tag}781048020@
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
{tag}781030585@
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
{tag}781033145@
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
{tag}781048020@
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
{tag}781028445@
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
{tag}704115727@
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
{tag}781033145@
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
{tag}781048020@
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
{tag}704115727@
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
{tag}781033145@
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
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Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
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Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
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Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
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Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
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Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
{tag}704115727@
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
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CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
{tag}781048020@
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
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COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
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CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
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Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
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CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
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Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
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CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
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Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
{tag}704115727@
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
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Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
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COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
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Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
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Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
{tag}781048020@
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
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COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
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CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
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Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
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COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
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CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
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Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
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CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
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Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
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CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
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Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
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COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
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Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
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COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
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Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
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Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
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Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
{tag}704115727@
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
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CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
{tag}704115727@
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
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CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
{tag}781028445@
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
{tag}781030585@
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
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CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
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COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
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COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
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For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
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COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
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CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
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Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
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COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
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CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
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Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
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CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
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Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
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CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
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Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
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COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
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Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
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COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
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Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
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Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
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Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
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COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
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CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
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COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
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CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
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CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
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CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
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COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
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COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
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COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems. SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
CANISTER VENT SOLENOID For information on the canister vent solenoid, refer to the description of the Evaporative Emission System.
Example: Six-Tower Coil Pack
COIL PACK A coil in a coil pack is turned ON (for example is coil charging) by the PCM, and is turned OFF when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.
Coil On Plug
COIL ON PLUG The COP ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management.
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.
CMP FMEM
During CMP FMEM the COP ignition works the same as during engine crank. This allows the engine to operate without the PCM knowing if cylinder one is under compression or exhaust.
ENGINE COOLING FAN CONTROL
CCRM Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C ON/OFF status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs. Although the FC, low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.
Stand-Alone Fan Control Relay Applications
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the LFC and HFC outputs.
Variable Load Control Module Applications
The Mark VIII uses a variable speed cooling fan, which is controlled by the PCM and Variable Load Control Module (VLCM). The PCM monitors certain engine parameters (such as ECT sensor, vehicle speed, A/C demand, A/C head pressure) to determine engine cooling fan needs. The PCM will send the desired fan speed to the VLCM through the BUS + and BUS - circuits. The VLCM then adjusts the fan speed according to vehicle battery positive voltage (B+) and outputs the appropriate voltage through the fan output driver with a pulsewidth modulated duty cycle. The following cooling fan information is sent from the VLCM to the PCM on the BUS + and BUS - circuits: Confirmation of cooling fan operation; any cooling fan secondary circuit faults that are detected.
EGR VACUUM REGULATOR SOLENOID For information on the EGR Vacuum Regulator (EVR) solenoid, refer to the description of the Exhaust Gas Recirculation Systems.
ELECTRIC SECONDARY AIR INJECTION PUMP For information on the electric secondary air injection pump, refer to the description of the Secondary Air Injection Systems.
EVAPORATIVE EMISSION CANISTER PURGE VALVE For information on the Evaporative Emission canister purge valve, refer to the description of the Evaporative Emission Systems.
FUEL PUMP
Applications Without a Fuel Pump Driver Module
The fuel pump is a PCM output signal that is used to control the electric fuel pump. With the electronic EC power relay contacts closed, vehicle Power (PWR) is sent to the coil of the fuel pump relay. For electric fuel pump operation, the PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition key is turned ON, the electric fuel pump runs for about one second, but is then turned OFF by the PCM if engine rotation is not detected.
Low Speed Fuel Pump Relay Wiring
For applications with two speed fuel pumps, a normally closed low speed fuel pump relay is wired into the FP PWR circuit. With the low speed fuel pump relay contacts in the normally closed position, full B+ is sent to the pump for high speed operation. For low speed fuel pump operation, the PCM will ground the Low Fuel Pump circuit, which opens the relay contacts. With the relay contacts open, power to the fuel pump must now pass through a resistor that is wired into the circuit.
Fuel Pump Driver Module Applications
The FP signal is a duty cycle command sent from the PCM to the Fuel Pump Driver Module (FPDM). The FPDM uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF.
FUEL INJECTORS For information on the fuel injectors, refer to the description of the Fuel Systems.
FUEL PRESSURE REGULATOR CONTROL SOLENOID For information on the fuel pressure regulator control solenoid, refer to the description of the Fuel Systems.
INTAKE MANIFOLD TUNING VALVE For information on the intake manifold tuning valve, refer to the description of the Intake Air Systems.
SECONDARY AIR INJECTION BYPASS SOLENOID For information on the secondary air injection bypass solenoid, refer to the description of the Secondary Air Injection Systems.
SECONDARY AIR INJECTION DIVERTER SOLENOID For information on the secondary air injection diverter solenoid, refer to the description of the Secondary Air Injection Systems.
SOLID STATE RELAY For information on the solid state relay, refer to the description of the Secondary Air Injection Systems.
TRANSMISSION CONTROL INDICATOR LAMP The transmission control indicator lamp is an output signal from the PCM that controls the lamp ON/OFF function depending on the engagement or disengagement of overdrive. Refer to Transmission Control Switch in Hardware PCM Inputs.
WIDE OPEN THROTTLE A/C CUT-OFF
CCRM Applications
For these applications, the wide open throttle A/C cutoff relay (may be referred to as the A/C relay) is normally open. There is no direct electrical connection between the A/C switch or EATC Module and the A/C clutch. The PCM will receive a signal indicating that A/C is requested (for Town Car and Continental, this message is sent through the BUS + and BUS - circuits). When A/C is requested, the PCM will check other A/C related inputs that are available (such as ACP (SW), ACCS). If these inputs indicate A/C operation is OK, and the engine conditions are OK (such as coolant temperature, engine rpm, throttle position), the PCM will ground the Wide Open Throttle A/C Cut-off output, closing the relay contacts and sending voltage to the A/C clutch.
The Variable Load Control Module (VLCM), which is used on the Mark VIII, does not use a separate output circuit for Wide Open Throttle (WOT) A/C Cut-off. Instead, the A/C clutch control information is included in the two-way communication (using the BUS+ and BUS- circuits) between the VLCM and PCM. When A/C is requested the PCM will verify that A/C operation is desirable (for example, the engine not cranking, overheated, not at WOT or A/C pressure is not excessive). If A/C operation is desirable, the PCM will send a message to the VLCM to turn on the A/C clutch.
The VLCM sends messages to the PCM (through the BUS + and BUS - circuits) indicating the A/C status (ON or OFF), and if any A/C circuit faults are detected.
The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is not desirable. Under normal conditions, with the A/C OFF, the PCM will ground the WAC output, which opens the normally closed WOT A/C cut-off relay (this relay may be inside the constant control relay module). When the A/C demand switch is turned ON, and the A/C cycling switch and A/C high pressure switch high pressure contacts are closed, voltage is supplied to the WOT A/C cut-off relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable (for example, engine not cranking, overheated or not at WOT). If A/C clutch operation is desirable, the PCM will adjust idle speed as necessary and "unground"the WAC output. This closes the normally closed WOT A/C cut-off relay and for all vehicles except Contour/Mystique, allows voltage to be supplied to the A/C clutch. For Contour/Mystique, when the WOT A/C cut-off relay contacts are closed voltage is supplied to the A/C clutch relay. This will close the normally open contacts of the A/C clutch relay and allow voltage to be supplied to the A/C clutch.
VAPOR MANAGEMENT VALVE For information on the vapor management valve (EVAP canister purge valve), refer to the description of the evaporative Emission Systems.
Heleodoro Rodriguez: como puedo detertar un corto ECM y ECU
Алексей: Здравствуйте, я планирую произвести свап двигателя с 1.6 BAD на 1.8T AGU, но я хочу последний собрать на ЭБУ о AUQ. Не могу никак найти схемы двигателей AUQ и AGU для сравнения. можете как то помочь мне?
Juan carlos: muy buena ayuda mucho
Arroas: Thank you
Rubén Darío de Jesús cedano : Gracias por el aporte
hsn1987iraq@yahoo.com: yos
Ricsko: Thank you!!! :)
juck: hizit
Rubén Darío de Jesús cedano : Bueno
Rubén Darío de Jesús cedano : Thank you
Rubén Darío de Jesús cedano : Thank you very much
Maikel: vielen dank für die geile seite
diego vasquez: como acceder alldata en linea
jimmy: COMO PUEDO ACSEDER A ALLDATA EN LÍNEA
ronald alberto rivas pino: tendra informacion sobre renaut , modelo scenic megane kangoo motor 1.6 16v k4m
ronald alberto rivas pino: Esto es lo maximo lo felicito por este aporte
Matias: hola podran agregar VW GOL CLI 1995 1600cc monopunto naafta motor UNC por favor muchas graacias
Jose Luis: porque no aparece la marca Fiat
Jose Gregorio Linares Maldonado: SALUDOS DESDE ESPAÑA,ESTA PLATAFORMA SIRVE PARA EL MERCADO EUROPEP.GRACIAS
daniel: te puedes ayudar con una punta de prueba la idea es que la camioneta la dejes como si estuvieras siempre en parking o neutro
daniel: rodolfo yo por ejemplo elimine el ramal y lo que hice fue pegar 2
Rodolfo: que puedo hacer para que el circuito de encendido funcione si lo cambie de automático a mecanico
StaticX: Будет ли поддержка грузового транспорта, в частности марка DAF?
juan : hola buenas noches
silvio buitrago: exelente de mucha ayuda mucccchas gracias
freddy: necesito el diagrama electrico del Opel Astra G 2002 Z18XE, gracias.
Brayan Rolando Conejo Solis: saludos desde costa rica
Tilek: eee
Radhames: Tienen manuales para Mitsubishi L200, 2008, Diesel.?
francisco: Hello
gabriel: muy bien por la pagina
Malathion: You could include Toyota GSIC.
Абросимов Константин: Lincoln navigator 2007?
Cristian: 100 eres un crak
Леонид: Схема Audi 100 c4 2.6 ABC
Lester Eleazar Rostrán Vásquez: Tenes el diagrama de Abs con los conectores??
Lester Eleazar Rostrán Vásquez: Tenes el diagrama de Abs con los conectores??
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указание на наличие у правообладателя прав на объект авторских и (или) смежных прав, размещенный на сайте в сети «Интернет» без разрешения правообладателя или иного законного основания;
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В течение двадцати четырех часов с момента получения уведомления, указанного в части 4 настоящей статьи, заявитель принимает меры, направленные на восполнение недостающих сведений, устранение неточностей и ошибок, и направляет владельцу сайта в сети «Интернет» уточненные сведения.
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Правила настоящей статьи в равной степени распространяются на правообладателя и на лицензиата, получившего исключительную лицензию на объект авторских и (или) смежных прав.»