Honda Accord: F-CAN Circuit Troubleshooting

1. Turn the ignition switch to LOCK (0).

2. Jump the SCS line with the HDS.

3. Disconnect ECM/PCM connector A (49P).

4. Measure the resistance between ECM/PCM connector terminals A3 and A4.

ECM/PCM CONNECTOR A (49P)

Terminal side of female terminals

Is there about 88-111 O? YES-Go to step 28.

NO-Go to step 5.

5. Disconnect these connectors:  - Gauge control module 32P (see page 22-351).

 - VSA modulator-control unit 36P (see page 19-136).

 - Yaw rate-lateral acceleration sensor 5P (see page 19-133).

 - SRS unit A (39P) (see page 24-228).

 - TPMS control unit (20P) (see page 18-83).

 -  Navigation unit B (32P) (if equipped) (see page 23-238).

6. Check for continuity between ECM/PCM connector terminals A3 and A4.

ECM/PCM CONNECTOR A (49P)

Terminal side of female terminals

Is there continuity? YES

-Repair short in the wires between ECM/PCM connector terminals A3 and A4. NO

-Go to step 7.

7. Check for continuity between ECM/PCM connector terminal A3 and gauge control module 32P connector terminal No. 30.

GAUGE CONTROL MODULE 32P CONNECTOR

Terminal side of female terminals

Is there continuity? YES-

Go to step 8.

NO

-Repair open in the wire between the ECM/PCM (A3) and the gauge control module

8. Check for continuity between ECM/PCM connector terminal A3 and VSA modulator-control unit 36P connector terminal No. 14.

VSA MODULATOR-CONTROL UNIT 36P CONNECTOR

Terminal side of female terminals

Is there continuity? YES-

Go to step 9.

NO

-Repair open in the wire between the ECM/PCM (A3) and the VSA modulator-control unit.

9. Check for continuity between ECM/PCM connector terminal A4 and gauge control module 32P connector terminal No. 29

GAUGE CONTROL MOD ULE 32P CONNECTOR

Terminal side of female terminals

Is there continuity? YES

-Go to step 10.

NO-

Repair open in the wire between the ECM/PCM (A4) and the gauge control module.

10, Check for continuity between ECM/PCM connector terminal A4 and VSA modulator-control unit 36P connector terminal No. 1.

VSA MODULATOR-CONTROL UNIT 36P CONNECTOR

Terminal side of female terminals

Is there continuity? YES

-Go to step 11.

NO-

Repair open in the wire between the ECM/PCM (A4) and the VSA modulator-control unit.G 11. Reconnect the gauge control module 32P connector.

12. Measure the resistance between ECM/PCM connector terminals A3 and A4.

ECM/PCM CONNECTOR A (49P)

Terminal side of female terminals

Is there about 2.34-2.86 kO?

YES

-Go to step 13.

NO

-Substitute a known-good gauge control module (see page 22-351), and reconnect ECM/PCM connector A (49P). If the HDS identifies the vehicle, replace the original gauge control module (see page 22-351 ) . 13. Disconnect the gauge control module 32P connector.

14. Reconnect the VSA modulator-control unit 36P connector.

15. Measure the resistance between ECM/PCM connector terminals A3 and A4.

ECM/PCM CONNECTOR A (49P)

Terminal side of female terminals

Is there about 108-132 O? YES

-Go to step 16.

NO

-Substitute a known-good VSA modulator-control unit (see page 19-136), and reconnect ECM/PCM connector A (49P). If the HDS identifies the vehicle, replace the original VSA modulator-control unit (see page 19-136).

16. Disconnect the VSA modulator-control unit 36P connector.

17. Reconnect the yaw rate-lateral acceleration sensor 5P connector.

18. Measure the resistance between ECM/PCM connector terminals A3 and A4.

ECM/PCM CONNECTOR A (49P)

Terminal side of female terminals

Is there about 2.34-2.86 kO? YES-Go to step 19.

NO-Substitute a known-good yaw rate-lateral acceleration sensor (see page 19-133), and reconnect ECM/PCM connector A (49P). If the HDS identifies the vehicle, replace the original yaw rate-lateral acceleration sensor (see page 19-133).

19. Disconnect the yaw-rate lateral acceleration sensor 5P connector.

20. Reconnect SRS unit connector A (39P).

21. Measure the resistance between ECM/PCM connector terminals A3 and A4.

ECM/PCM CONNECTOR A (49P)

Terminal side of female terminals

Is there about 2.34-2,86 kD? YES

-Go to step 22.

NO

-Substitute a known-good SRS unit (see page 24-228), and reconnect ECM/PCM connector A (49P). If the HDS identifies the vehicle, replace the original SRS unit (see page 24-228).

22. Disconnect SRS unit connector A (39P).

23. Reconnect the TPMS control unit 20P connector.

24. Measure the resistance between ECM/PCM connector terminals A3 and A4 .

ECM/PCM CONNECTOR A (49P)

Terminal side of female terminals

Is there about 2.34-2.86 kO?

YES-

- With navigation: Go to step 25.

- Without navigation: Update the ECM/PCM if it does not have the latest software (see page 11-203), or substitute a known-good ECM/PCM (see page 11-7), then recheck. If the HDS identifies the vehicle and the ECM/PCM was updated, troubleshooting is complete. If the HDS identifies the vehicle and the ECM/PCM was substituted, replace the original ECM/PCM (see page 11-204

NO-

Substitute a known-good TPMS control unit (see page 18-83), and reconnect ECM/PCM connector A (49P). If the HDS identifies the vehicle, replace the original TPMS control unit (see page 18-83).

25. Disconnect the TPMS control unit 20P connector.

26. Reconnect navigation unit connector B (32P).

27. Measure the resistance between ECM/PCM connector terminals A3 and A4.

ECM/PCM CONNECTOR A (49P)

Terminal side of female terminals

Is there about 2.34-2,86 kD? YES

-Update the ECM/PCM if it does not have the latest software (see page 11-203), or substitute a known-good ECM/PCM (see page 11-7), then recheck.

if the HDS identifies the vehicle and the ECM/PCM was updated, troubleshooting is complete. If the HDS identifies the vehicle and the ECM/PCM was substituted, replace the original ECM/PCM (see page 11-204).

NO

-Substitute a known-good navigation unit (see page 23-238), and reconnect ECM/PCM connector A (49P). If the HDS identifies the vehicle, replace the original navigation unit (see page 23-238).

28. Disconnect these connectors:  - Gauge control module 32P (see page 22-351).

 - VSA modulator-control unit 36P (see page 19-136).

 - Yaw rate-lateral acceleration sensor 5P (see page 19-133).

 -  SRS unit A (39P) (see page 24-228).

 - TPMS control unit (20P) (see page 18-83).

 -  Navigation unit B (32P) (if equipped) (see page 23-238).

29. Check for continuity between ECM/PCM connector terminal A3 and body ground.

ECM/PCM CONNECTOR A (49P)

Terminal side of female terminals

Is there continuity? YES

-Repair short in the wire between the ECM/PCM (A3) and the gauge control module, the VSA modulator-control unit, the yaw rate-lateral acceleration sensor, the SRS unit, the TPMS control unit, the navigation unit, or the DLC.

NO-Go to step 30.

30. Check for continuity between ECM/PCM connector terminal A4 and body ground.

ECM/PCM CONNECTOR A (49P)

Terminal side of female terminals

Is there continuity? YES

-Repair short in the wire between the ECM/PCM (A4) and the gauge control module, the VSA modulator-control unit, the yaw rate-lateral acceleration sensor, the SRS unit, the TPMS control unit, the navigation unit, or the D L C . NO

-Go to step 31.

31. Reconnect all connectors.

32. Connect the HDS to the DLC (see page 11-3).

33. Disconnect the gauge control module 32P connector.

34. Turn the ignition switch to ON (II), and read the HDS.

Does the HDS identify the vehicle? YES

-Replace the gauge control module (see page 22-351 ) . NO

-Go to step 35.

35. Turn the ignition switch to LOCK (0).

36. Reconnect the gauge control module 32P connector.

37. Disconnect the VSA modulator-control unit 36P connector.

38. Turn the ignition switch to ON (II), and read the HDS.

Does the HDS identify the vehicle? YES

-Replace the VSA modulator-control unit (see page 19-136).

NO

-Go to step 39.

39. Turn the ignition switch to LOCK (0).

40. Reconnect the VSA modulator-control unit 36P connector.

41. Disconnect the yaw rate-lateral acceleration sensor 5P connector.

42. Turn the ignition switch to ON (II), and read the HDS.

Does the HDS identify the vehicle? YES

-Replace the yaw rate-lateral acceleration sensor (see page 19-133).

NO

-Go to step 43.

43. Turn the ignition switch to LOCK (0).

44. Reconnect the yaw rate-lateral acceleration sensor 5P connector.

45. Disconnect SRS unit connector A (39P).

46. Turn the ignition switch to ON (II), and read the HDS.

Does the HDS identify the vehicle? YES-

Replace the SRS unit (see page 24-228).

NO

-Go to step 47.

47. Turn the ignition switch to LOCK (0).

48. Reconnect SRS unit connector A (39P).

49. Disconnect the TPMS control unit 20P connector.

50. Turn the ignition switch to ON (II), and read the HDS.

Does the HDS identify the vehicle? YES

-Replace the TPMS control unit (see page 18-83).

NO-

- With navigation: Go to step 51.

- Without navigation: Update the ECM/PCM if it does not have the latest software (see page 11-203), or substitute a known-good ECM/PCM (see page 11-7), then recheck. If the HDS identifies the vehicle and the ECM/PCM was updated, troubleshooting is complete. If the HDS identifies the vehicle and the ECM/PCM was substituted, replace the original ECM/PCM (see page 11-204).

51. Turn the ignition switch to LOCK (0).

52. Reconnect the TPMS control unit 20P connector.

53. Disconnect navigation unit connector B (32P).

54. Turn the ignition switch to ON (ll)f and read the HDS.

Does the HDS identify the vehicle? YES

-Replace the navigation unit (see page 23-238).

NO

-Update the ECM/PCM if it does not have the latest software (see page 11-203), or substitute a known-good ECM/PCM (see page 11-7), then recheck.

If the HDS identifies the vehicle and the ECM/PCM was updated, troubleshooting is complete. If the HDS identifies the vehicle and the ECM/PCM was substituted, replace the original ECM/PCM (see page 11-204).