Acura TSX / Honda Accord CL. Manual — part 589

Fig. 17: Measuring Voltage Between ECM/PCM Connector Terminal B8 & Body Ground

13. Turn the ignition switch OFF.

14. Replace the ECT sensor (see ECT SENSOR REPLACEMENT ).

15. Turn the ignition switch ON (II).

16. Reset the ECM/PCM with the HDS.

17. Do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN PROCEDURE ).

18. Check for Temporary DTCs or DTCs in the DTCs MENU with the HDS.

2004 Acura TSX

2004 ENGINE PERFORMANCE PGM-FI System - TSX

Are any Temporary DTCs or DTCs indicated?

YES: If DTC P0118 is indicated, check for poor connections or loose terminals at the ECT
sensor and the ECM/PCM, then go to step 1 . If any other Temporary DTCs or DTCs are
indicated, go to the indicated DTC troubleshooting.

NO: Troubleshooting is complete.

19. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM (see

HOW TO SUBSTITUTE THE ECM/PCM ).

20. Check for Temporary DTCs or DTCs in the DTCs MENU with the HDS.

Are any Temporary DTCs or DTCs indicated?

YES: If DTC P0118 is indicated, check for poor connections or loose terminals at the ECT
sensor and the ECM/PCM, then go to step 1 . If any other Temporary DTCs or DTCs are
indicated, go to the indicated DTC troubleshooting.

NO: If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was
substituted, replace the original ECM/PCM (see HOW TO REMOVE THE ECM/PCM
FOR TESTING ).

DTC P0125: ECT SENSOR MALFUNCTION/SLOW RESPONSE

1. Start the engine, and let it idle.

2. Check the ECT SENSOR in the DATA LIST with the HDS.

Is about 86°F (30°C) or less, or 2.61 V or higher indicated?

YES: Go to step 3.

NO: Intermittent failure, system is OK at this time. Check the thermostat and the cooling
system.

3. Let the engine idle for 6 minutes.

4. Check the ECT SENSOR in the DATA LIST with the HDS.

Is about 86°F (30°C) or less, or 2.61 V or higher indicated?

YES: Go to step 5.

NO: Intermittent failure, system is OK at this time. Check the thermostat and the cooling
system.

5. Turn the ignition switch OFF.

6. Replace the ECT sensor (see ECT SENSOR REPLACEMENT ).

7. Turn the ignition switch ON (II).

8. Reset the ECM/PCM with the HDS.

9. Do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN PROCEDURE ).

10. Allow the engine to cool between 23°F (-5°C) and 77°F (25°C).

11. Start the engine, and let it idle for 20 minutes.

12. Check for Temporary DTCs or DTCs in the DTCs MENU with the HDS.

Are any Temporary DTCs or DTCs indicated?

YES: If DTC P0125 is indicated, check for poor connections or loose terminals at the ECT

2004 Acura TSX

2004 ENGINE PERFORMANCE PGM-FI System - TSX

sensor and the ECM/PCM, then go to step 1 . If any other Temporary DTCs or DTCs are
indicated, go to the indicated DTC troubleshooting.

NO: Go to step 13.

13. Monitor the OBD STATUS for DTC P0125 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?

YES: Troubleshooting is complete.

NO: If the screen indicates FAILED, check for poor connections or loose terminals at the
ECT sensor and the ECM/PCM, then go to step 1 . If the screen indicates NOT
COMPLETED, go to step 10 and recheck.

DTC P0128: COOLING SYSTEM MALFUNCTION

1. Turn the ignition switch ON (II).

2. Clear the DTC with the HDS.

3. Turn the blower switch OFF.

4. Turn the A/C switch OFF.

5. Check the FAN CTRL in the DATA LIST with the HDS.

Is it OFF?

YES: Go to step 6.

NO: Wait until the FAN CTRL is turned off, then go to step 6.

6. Check the ECT SENSOR in the DATA LIST with the HDS, then check the radiator fan operation.

Does the radiator fan keep running when the engine coolant temperature is less than 158°F
(70°C)?

YES: Check the radiator fan circuit (see RADIATOR FAN CIRCUIT TROUBLE
SHOOTING ), the radiator fan switch circuit (see RADIATOR FAN SWITCH CIRCUIT
TROUBLE SHOOTING ), and the radiator fan switch (see RADIATOR FAN SWITCH ).
If the circuits and the switch are OK, go to step 21 .

NO: Go to step 7.

NOTE:

If the DTCs listed below are stored at the same time as DTC P0128, troubleshoot
those DTCs first, then recheck for P0128. DTC P0128 can occasionally set when
the hood is opened while the engine is running.

P0112, P0113: Intake air temperature (IAT) sensor

P0116, P0117, P0118, P0125: Engine coolant temperature (ECT) sensor

P0300: Random misfire

P0301, P0302, P0303, P0304: No. 1, No. 2, No. 3, or No. 4 cylinder misfire

P0335, P0339: Crankshaft position (CKP) sensor

P2227, P2228, P2229: Barometric pressure (BARO) sensor

P2646, P2647, P2648, P2648: VTEC system

P0506, P0507: Idle control system malfunction

2004 Acura TSX

2004 ENGINE PERFORMANCE PGM-FI System - TSX

7. Start the engine. Hold the engine speed at 3,000 RPM with no load (in Park or neutral) until the radiator

fan comes on, then let it idle.

8. Turn the ignition switch OFF.

9. Turn the ignition switch ON (II).

10. Do the RADIATOR FAN TEST in the INSPECTION MENU with the HDS for 20 minutes.

11. Check the ECT SENSOR in the DATA LIST with the HDS.

Is about 151°F (66°C) or less, or 1.25 V or more indicated?

YES: Intermittent failure, system is OK at this time.

NO: Go to step 12.

12. Turn the ignition switch OFF.

13. Cool down the engine until the coolant temperature is between 23°F (-5°C) and 95°F (35°C).

14. Replace the thermostat (see THERMOSTAT REPLACEMENT ).

15. Turn the ignition switch ON (II).

16. Reset the ECM/PCM with the HDS.

17. Do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN PROCEDURE ).

18. Start the engine. Hold the engine speed at 3,000 RPM with no load (in Park or neutral) until the radiator

fan comes on, then let it idle.

19. Check for Temporary DTCs or DTCs in the DTCs MENU with the HDS.

Are any Temporary DTCs or DTCs indicated?

YES: If DTC P0128 is indicated, check the cooling system, then go to step 1 . If any other
Temporary DTCs or DTCs are indicated, go to the indicated DTC troubleshooting.

NO: Go to step 20.

20. Monitor the OBD STATUS for DTC P0128 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?

YES: Troubleshooting is complete.

NO: If the screen indicates FAILED, check cooling system, then go to step 1 . If the screen
indicates NOT COMPLETED, go to step 18 and recheck.

21. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM (see

HOW TO SUBSTITUTE THE ECM/PCM ).

22. Cool down the engine until the coolant temperature is between 23°F (-5°C) and 95°F (35°C).

23. Start the engine. Hold the engine speed at 3,000 RPM with no load (in Park or neutral) until the radiator

fan comes on, then let it idle.

24. Check for Temporary DTCs or DTCs in the DTCs MENU with the HDS.

Are any Temporary DTCs or DTCs indicated?

YES: If DTC P0128 is indicated, check for poor connections or loose terminals at the ECT
sensor and the ECM/PCM, then go to step 1 . If any other Temporary DTCs or DTCs are
indicated, go to the indicated DTC troubleshooting.

NO: If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was
substituted, replace the original ECM/PCM (see HOW TO REMOVE THE ECM/PCM
FOR TESTING ).

2004 Acura TSX

2004 ENGINE PERFORMANCE PGM-FI System - TSX