Fig. 1: Identifying Fan Controls Component Location
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'04-05 models
SYMPTOM TROUBLESHOOTING CHART - 04-05 MODELS
Symptom
Diagnostic procedure
Also check for
Engine overheats
The radiator fan does not run at all
Radiator fan circuit troubleshooting (see RADIATOR FAN CIRCUIT TROUBLESHOOTING
).
Cleanliness and tightness of all connectors
The radiator fan does not run for engine cooling, but it runs with the A/C on
Radiator fan switch circuit troubleshooting (Open) (see RADIATOR FAN SWITCH CIRCUIT TROUBLESHOOTING (OPEN)
).
Cleanliness and tightness of all connectors
The radiator fan runs with the ignition switch ON (II), the A/C off, and the engine coolant temperature below 199°F (93°C)
Radiator fan switch circuit troubleshooting (Short) (see RADIATOR FAN SWITCH CIRCUIT TROUBLESHOOTING (SHORT)
).
Cleanliness and tightness of all connectors
The A/C condenser fan does not run at all (but the radiator fan runs with the A/C on)
A/C condenser fan circuit troubleshooting (see
A/C CONDENSER FAN CIRCUIT TROUBLESHOOTING
).
Both the radiator fan and the A/C condenser fan do not run with the A/C on (but the A/C compressor runs with the A/C on)
Radiator and A/C condenser fan common circuit troubleshooting (see
RADIATOR AND A/C CONDENSER FAN COMMON CIRCUIT TROUBLESHOOTING
).
'06-08 models
SYMPTOM TROUBLESHOOTING CHART - 06-08 MODELS
Symptom
Diagnostic procedure
Also check for
Engine overheats
The radiator fan does not run at all
Cleanliness and tightness of all connectors
Both the radiator fan and the A/C condenser fan run with the ignition switch ON (II), the A/C off, and the engine coolant temperature below 199°F (93°C)
Remove the radiator fan relay, and test.
Cleanliness and tightness of all connectors
The A/C condenser fan does not run at all (but the radiator fan runs with the A/C on)
A/C condenser fan circuit troubleshooting (see
A/C CONDENSER FAN CIRCUIT TROUBLESHOOTING
).
Both the radiator fan and the A/C condenser fan do not run with the A/C on (but the A/C compressor runs with the A/C on)
Radiator and A/C condenser fan common circuit troubleshooting (see
RADIATOR AND A/C CONDENSER FAN COMMON CIRCUIT TROUBLESHOOTING
).
The A/C compressor clutch does not engage (but both the radiator fan and the A/C condenser fan run with the A/C on)
A/C compressor clutch circuit troubleshooting (see
A/C COMPRESSOR CLUTCH CIRCUIT TROUBLESHOOTING
).
Fig. 2: Fan Controls Circuit Diagram
Courtesy of AMERICAN HONDA MOTOR CO., INC.
NOTE:
Before beginning this troubleshooting procedure, refer to the SYMPTOM TROUBLESHOOTING INDEX.
Are the fuses OK?
YES - Go to step 2.
NO - Replace the f use(s) and recheck.
Is the relay OK?
YES - Go to step 3.
NO - Replace the radiator fan relay.
Fig. 3: Measuring Voltage Between Radiator Fan Relay 4P Socket Terminal No. 2 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES - Go to step 4.
NO - Replace the under-hood fuse/relay box.
Fig. 4: Connecting Radiator Fan Relay 4P Socket Terminal No. 1 And No. 2 With Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Does the radiator fan run?
YES - Go to step 5.
NO - Go to step 6.
Fig. 5: Measuring Voltage Between Radiator Fan Relay 4P Socket Terminal No. 3 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES - Go to step 9.
NO - Repair open in the wire between the under-hood fuse/relay box and under-dash fuse/relay box.
Fig. 6: Checking Continuity Between Radiator Fan Relay 4P Socket Terminal No. 1 And Radiator Fan Motor 2P Terminal No. 2
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES - Go to step 8.
NO - Repair open in the wire between the under-hood fuse/relay box and radiator fan motor 2P connector terminal No. 2.
Fig. 7: Checking Continuity Between Radiator Fan Motor 2P Connector Terminal No. 1 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES - Replace the radiator fan motor (see RADIATOR AND FAN REPLACEMENT ).
NO -Repair open in the wire between radiator fan motor 2P connector terminal No. 1 and body ground. If the wire is OK, check for a poor ground at G301.
Fig. 8: Connecting Radiator Fan Switch 2P Connector Terminal No. 1 And No. 2 With Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Does the radiator fan run?
YES - Replace the radiator fan switch (see RADIATOR FAN SWITCH REPLACEMENT ).
NO - Go to step 12.
Fig. 9: Measuring Voltage Between Radiator Fan Switch 2P Connector Terminal No. 2 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES - Repair open in the wire between radiator fan switch 2P connector terminal No. 1 and body ground. If the wire is OK, check for a poor ground at G301.
NO - Repair open in the wire between radiator fan switch 2P connector terminal No. 2 and the under-hood fuse/relay box.
NOTE:
Before beginning this troubleshooting procedure, refer to the SYMPTOM TROUBLESHOOTING INDEX.
Are the fuses OK?
YES - Go to step 3.
NO - Replace the fuse(s) and recheck.
Is the relay OK?
YES - Go to step 4.
NO - Replace the radiator fan relay.
Fig. 10: Measuring Voltage Between Radiator Fan Relay 4P Socket Terminal No. 2 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES - Go to step 5.
NO - Replace the under-hood fuse/relay box.
Fig. 11: Connecting Radiator Fan Relay 4P Socket Terminal No. 1 And No. 2 With A Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Does the radiator fan run?
YES - Go to step 6.
NO - Go to step 7.
Fig. 12: Checking Voltage Between Radiator Fan Relay 4P Socket Terminal No. 3 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES - Go to step 10.
NO - Repair open in the wire between the under-hood fuse/relay box and under-dash fuse/relay box.
Fig. 13: Checking Continuity Between Radiator Fan Relay 4P Socket Terminal No. 1 And Radiator Fan Motor 2P Terminal No. 2
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES - Go to step 9.
NO - Repair open in the wire between the under-hood fuse/relay box and radiator fan motor 2P connector terminal No. 2.a
Fig. 14: Checking Continuity Between Radiator Fan Motor 2P Connector Terminal No. 1 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES - Replace the radiator fan motor (see RADIATOR AND FAN REPLACEMENT ).
NO - Repair open in the wire between radiator fan motor 2P connector terminal No. 1 and body ground. If the wire is OK, check for a poor ground at G301.
NOTE:
This step must be done to protect the ECM/PCM from damage.
Fig. 15: Checking Continuity Between ECM/PCM Connector Terminal E12 And Under-Hood Fuse/Relay Box Terminal E14
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES - Circuit is OK. Update the ECM/PCM if it does not have the latest software (see UPDATING THE ECM/PCM ), or substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then recheck. if the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see ECM/PCM REPLACEMENT ).
NO - Repair open in the wire between the under-hood fuse/relay box and the ECM/PCM.
NOTE:
Before beginning this troubleshooting procedure, refer to the SYMPTOM TROUBLESHOOTING INDEX.
Fig. 16: Measuring Voltage Between Radiator Fan Switch 2P Connector Terminal No. 2 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES - Go to step 4.
NO - Repair open in the wire between radiator fan switch 2P connector terminal No. 2 and under-hood fuse/relay box.
Fig. 17: Checking Continuity Between Radiator Fan Switch 2P Connector Terminal No. 1 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES - Replace the radiator fan switch (see RADIATOR FAN SWITCH REPLACEMENT ).
NO - Repair open in the wire between radiator fan switch 2P connector terminal No. 1 and body ground. If the wire is OK, check for a poor ground at G301.
NOTE:
Before beginning this troubleshooting procedure, refer to the SYMPTOM TROUBLESHOOTING INDEX.
Is the relay OK?
YES - Go to step 2.
NO - Replace the radiator fan relay.
Is the radiator fan switch OK?
YES - Go to step 3.
NO - Replace the radiator fan switch (see RADIATOR FAN SWITCH REPLACEMENT ).
Fig. 18: Checking Continuity Between Radiator Fan Switch 2P Connector Terminal No. 2 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES - Repair short in the wire between radiator fan switch 2P connector terminal No. 2 and under-hood fuse/relay box.
NO - Replace the under-hood fuse/relay box.
NOTE:
Bleed air from the cooling system after installing the radiator fan switch (see
COOLANT REPLACEMENT
).
Fig. 19: Suspending Radiator Fan Switch In Container Of Water
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Fig. 20: Measuring Continuity Between Terminal No. 1 And Terminal No. 2
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Fig. 21: Identifying Radiator Fan Switch Connector And Radiator Fan Switch W/Torque Specification
Courtesy of AMERICAN HONDA MOTOR CO., INC.