• HEADINGS
  • Component Location Index
  • Throttle Body Test
    • Carbon Accumulation Check
    • Throttle Position Learning Check
  • Throttle Body Cleaning
  • Intake Air Bypass Control Thermal Valve Test
  • Air Cleaner Removal/Installation
  • Air Cleaner Element Inspection/ Replacement
  • Resonator Removal/Installation
  • Throttle Cable Adjustment
  • Throttle Cable Removal/Installation
  • Intake Air Bypass Control Thermal Valve Replacement
  • Throttle Body Removal/Installation
  • Throttle Body Disassembly/Reassembly
  • Accelerator Pedal Replacement
• FIGURES
  • Fig. 1: Identifying Intake Air System Component Location
  • Fig. 2: Identifying Data Link Connector (DLC)
  • Fig. 3: Connecting HDS To DLC
  • Fig. 4: Identifying Throttle Shaft
  • Fig. 5: Identifying Vacuum Hose
  • Fig. 6: Identifying Bolts And Clamp W/Torque Specification
  • Fig. 7: Identifying Air Cleaner Bolts And Air Cleaner Housing Cover W/Torque Specification
  • Fig. 8: Identifying Intake Air Cover And Intake Air Duct W/Torque Specification
  • Fig. 9: Identifying Throttle Cable Cover
  • Fig. 10: Identifying Cable Free Play
  • Fig. 11: Identifying Throttle Cable, Throttle Link, Cable Housing And Cable Bracket
  • Fig. 12: Identifying Throttle Cable And Accelerator Pedal W/Torque Specification
  • Fig. 13: Identifying Adjusting Nut And Bracket W/Torque Specification
  • Fig. 14: Identifying Hoses W/Torque Specification - '04-05 Models
  • Fig. 15: Identifying Hoses W/Torque Specification - '06-08 Models
  • Fig. 16: Identifying Throttle Body Components W/Torque Specification - '04-05 Models
  • Fig. 17: Exploded View Of Throttle Body W/Torque Specifications
  • Fig. 18: Identifying Accelerator Pedal Bracket W/Torque Specifications
• TABLES

2004-08 ENGINE PERFORMANCE

Intake Air System - TSX

Component Location Index

Fig. 1: Identifying Intake Air System Component Location
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Throttle Body Test

Carbon Accumulation Check

NOTE:

If the malfunction indicator lamp (MIL) has been reported on, check for diagnostic trouble codes (DTCs).

1. Connect the HDS to the data link connector (DLC) (A) located under the driver's side of the dashboard.

   Fig. 2: Identifying Data Link Connector (DLC)
   Courtesy of AMERICAN HONDA MOTOR CO., INC.

2. Turn the ignition switch ON (II).
3. Make sure the HDS communicates with the ECM/PCM. If it doesn't, go to the DLC circuit troubleshooting, '04-06 models (see '04-06 MODELS ), '07-08 models (see '07-08 MODELS ).
4. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle.
5. Check REL TP SENSOR in the DATA LIST with the HDS. The reading should be below 2.46 deg. If it is not, clean the throttle body (see THROTTLE BODY CLEANING ).

Throttle Position Learning Check

NOTE:

If the malfunction indicator lamp (MIL) has been reported on, check for diagnostic trouble codes (DTCs).

1. Connect the HDS to the data link connector (DLC) (A) located under the driver's side of the dashboard.

   Fig. 3: Connecting HDS To DLC
   Courtesy of AMERICAN HONDA MOTOR CO., INC.

2. Turn the ignition switch ON (II).
3. Make sure the HDS communicates with the ECM/PCM. If it doesn't, go to the DLC circuit troubleshooting, '04-06 models (see '04-06 MODELS ), '07-08 models (see '07-08 MODELS ).
4. Select the INSPECTION MENU with the HDS.
5. Do the TP POSITION CHECK in the ETCS TEST. If needed, clean the throttle body (see THROTTLE BODY CLEANING ).

Throttle Body Cleaning

CAUTION:

Do not insert your fingers into the installed throttle body when you turn the ignition switch ON (II) or while the ignition switch is ON (II). If you do, you will seriously injure your fingers if the throttle valve is activated.

1. Check for damage to the air cleaner. If the air cleaner is damaged, replace it (see AIR CLEANER ELEMENT INSPECTION/ REPLACEMENT ).
2. Remove the throttle body (see THROTTLE BODY REMOVAL/INSTALLATION ).
3. Clean off the carbon from the throttle valve and inside the throttle body with a paper towel soaked in throttle plate and induction cleaner.

   NOTE:

   Remove the throttle body to clean it. Be careful not to pinch your fingers. To avoid removing the molybdenum coating, do not clean the bearing area of the throttle shaft (A). Do not spray throttle plate and induction cleaner directly on the throttle body. Use Honda genuine throttle plate and induction cleaner. Fig. 4: Identifying Throttle Shaft Courtesy of AMERICAN HONDA MOTOR CO., INC.

4. Install the throttle body (see THROTTLE BODY REMOVAL/INSTALLATION ).
5. Reset the ECM/PCM with the HDS.
6. Turn the ignition switch ON (II), and wait 2 seconds.
7. Do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN PROCEDURE ).

Intake Air Bypass Control Thermal Valve Test

Special Tools Required

Vacuum pump/gauge, 0-30 in.Hg, Snap-on YA4000A or equivalent, commercially available

1. Start the engine, and let it idle.

   NOTE:

   The engine coolant temperature must be below 131°F (55°C).

2. Remove the vacuum hose (A) from the intake air duct, and connect a vacuum pump/gauge, 0-30 in.Hg, to the hose.

   Fig. 5: Identifying Vacuum Hose
   Courtesy of AMERICAN HONDA MOTOR CO., INC.

3. Raise and lower the engine speed; the vacuum gauge reading should change as the engine speed changes.

   If the vacuum reading does not change, check for these problems:

   • Misrouted, leaking, broken, or clogged intake air bypass control system vacuum lines.
   • A cracked or damaged intake air bypass control thermal valve. Replace the valve if needed (see INTAKE AIR BYPASS CONTROL THERMAL VALVE REPLACEMENT ).
4. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle.
5. Raise and lower the engine speed, and make sure the vacuum gauge reading does not change as the rpm changes.

   If there is a vacuum reading, check for these problems:

   • Misrouted, leaking, broken, or clogged intake air bypass control system vacuum lines.
   • A cracked or damaged intake air bypass control thermal valve. Replace the valve if needed (see INTAKE AIR BYPASS CONTROL THERMAL VALVE REPLACEMENT ).

Air Cleaner Removal/Installation

1. Remove the bolts (A) and clamp (B).

   Fig. 6: Identifying Bolts And Clamp W/Torque Specification
   Courtesy of AMERICAN HONDA MOTOR CO., INC.

2. Remove the air cleaner (C).
3. Install the parts in the reverse order of removal.

Air Cleaner Element Inspection/ Replacement

1. Remove the air cleaner bolts (A) and the air cleaner housing cover (B).

   Fig. 7: Identifying Air Cleaner Bolts And Air Cleaner Housing Cover W/Torque Specification
   Courtesy of AMERICAN HONDA MOTOR CO., INC.

2. Remove the air cleaner element (C) from the air cleaner housing (D).
3. Check the air cleaner element for damage or clogging. If it is damage or clogging, replace it.

   NOTE:

   Do not use compressed air to clean the air cleaner element.

4. Clean and remove any debris from inside the air cleaner housing.
5. Install the parts in the reverse order of removal.
6. Reset the maintenance minder, if needed (see RESETTING THE MAINTENANCE INFORMATION DISPLAY ).

Resonator Removal/Installation

1. Remove the front bumper (see FRONT BUMPER REMOVAL/INSTALLATION ).
2. Remove the intake air cover (A), then remove the intake air duct (B).

   Fig. 8: Identifying Intake Air Cover And Intake Air Duct W/Torque Specification
   Courtesy of AMERICAN HONDA MOTOR CO., INC.

3. Remove the resonator (C).
4. Install the parts in the reverse order of removal.

Throttle Cable Adjustment

1. Remove the throttle cable cover (A).

   Fig. 9: Identifying Throttle Cable Cover
   Courtesy of AMERICAN HONDA MOTOR CO., INC.

2. Check cable free play at the throttle linkage. Cable free play (A) should be 0.59-0.71 in. (15-18 mm).

   Fig. 10: Identifying Cable Free Play
   Courtesy of AMERICAN HONDA MOTOR CO., INC.

3. If the free play is not within spec (0.59-0.71 in., 15-18 mm), loosen the locknut (B), turn the adjusting nut (C) until the deflection is as specified, then retighten the locknut.
4. With the cable properly adjusted, check the throttle link to be sure it opens fully when you push the accelerator pedal to the floor. Also check the throttle link to be sure it returns whenever you release the accelerator pedal.

Throttle Cable Removal/Installation

1. Remove the throttle cable cover (see THROTTLE CABLE ADJUSTMENT ).
2. Fully open the throttle link, then remove the throttle cable (A) from the throttle link (B).

   Fig. 11: Identifying Throttle Cable, Throttle Link, Cable Housing And Cable Bracket
   Courtesy of AMERICAN HONDA MOTOR CO., INC.

3. Remove the cable housing (C) from the cable bracket (D).
4. Remove the throttle cable (A) from the accelerator pedal (B).

   Fig. 12: Identifying Throttle Cable And Accelerator Pedal W/Torque Specification
   Courtesy of AMERICAN HONDA MOTOR CO., INC.

5. Install the parts in the reverse order of removal.
6. Hold the cable, removing all slack from it.
7. Set the cable on the bracket (A).

   Turn the adjusting nut (B) so that its free play is 0 mm.

   Fig. 13: Identifying Adjusting Nut And Bracket W/Torque Specification
   Courtesy of AMERICAN HONDA MOTOR CO., INC.

8. Position the adjusting nut on the other side of the bracket, then tighten the locknut (C).
9. Check the throttle cable free play (see THROTTLE CABLE ADJUSTMENT ).
10. With the cable properly adjusted, check the throttle link to be sure it opens fully when you push the accelerator pedal to the floor. Also check the throttle link to be sure it returns whenever you release the accelerator pedal.

Intake Air Bypass Control Thermal Valve Replacement

1. Remove the engine cover; '04-05 models (see REMOVAL ('04-05 MODELS) ), '06-08 models (see REMOVAL ('06-08 MODELS) ).
2. Remove the throttle cable bracket.
3. Disconnect the hoses (A).

   '04-05 models

   Fig. 14: Identifying Hoses W/Torque Specification - '04-05 Models
   Courtesy of AMERICAN HONDA MOTOR CO., INC.

   '06-08 models

   Fig. 15: Identifying Hoses W/Torque Specification - '06-08 Models
   Courtesy of AMERICAN HONDA MOTOR CO., INC.

4. Remove the intake air bypass control thermal valve (B).
5. Install the parts in the reverse order of removal.

   NOTE:

   Position the valve angle as shown. '06-08 models: Make sure the center of clamp (C) and the lever end of clamp (D) are the position within the range shown.

Throttle Body Removal/Installation

CAUTION:

Do not insert your fingers into the installed throttle body when you turn the ignition switch ON (II) or while the ignition switch is ON (II). If you do, you will seriously injure your fingers if the throttle valve is activated.

NOTE:

If you are replacing the throttle body, begin from step 1. If you are removing the throttle body, skip step 1 to 3, and begin from step 4.

1. Connect the HDS while the engine is stopped.
2. Select the INSPECTION MENU with the HDS.
3. Do the TP POSITION CHECK in the ETCS TEST.
4. Turn the ignition switch OFF.
5. Disconnect the IAT sensor 2P connector (A), and remove the intake air duct (B).

   Fig. 16: Identifying Throttle Body Components W/Torque Specification - '04-05 Models
   Courtesy of AMERICAN HONDA MOTOR CO., INC.

6. Disconnect the throttle body 6P connector (C).
7. Disconnect the water bypass hoses (D), and plug them.
8. Disconnect the vacuum hose (E).
9. Remove the harness clip (F) and the throttle body (G).
10. Install the parts in the reverse order of removal with a new gasket (H), then do this:
    • Do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN PROCEDURE ).
    • Refill the radiator with engine coolant; '04-05 models (see '04-05 MODELS ), '06-08 models (see '06-08 MODELS ).

Throttle Body Disassembly/Reassembly

Fig. 17: Exploded View Of Throttle Body W/Torque Specifications
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Accelerator Pedal Replacement

1. Remove the throttle cable from the accelerator pedal (see THROTTLE CABLE REMOVAL/INSTALLATION ).
2. Remove the accelerator pedal bracket (A).

   Fig. 18: Identifying Accelerator Pedal Bracket W/Torque Specifications
   Courtesy of AMERICAN HONDA MOTOR CO., INC.

3. Install the parts in the reverse order of removal.