Operation CHARM: Car repair manuals for everyone.
Home >> Honda >> 2012 >> Fit L4-1.5L >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Information Bus >> Testing and Inspection >> Component Tests and General Diagnostics >> F-CAN Circuit Troubleshooting

F-CAN Circuit Troubleshooting




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), then disconnect the HDS.

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





Is there about 85-111 Ohms?

YES -

Go to step 38.

NO -

Go to step 5.

5. Disconnect these connectors:

- Gauge control module 32P Service and Repair.
- VSA modulator-control unit 36P (with VSA system).
- Yaw rate-lateral acceleration sensor 5P (with VSA system).
- ABS modulator-control unit 25P (with ABS).
- EPS control unit A (11P) Service and Repair.
- SRS unit A (39P) Service and Repair.
- TPMS control unit 20P Service and Repair.
- Audio-navigation unit D (20P) Audio-Navigation Unit Removal/Installation (With Navigation)

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





Is there continuity?

YES -

Repair a short in the wire between ECM/PCM 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.





Is there continuity?

YES -

- With VSA system: Go to step 8.
- With ABS: Go to step 9.

NO -

Repair an 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.





Is there continuity?

YES -

Go to step 10.

NO -

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

9. Check for continuity between ECM/PCM connector terminal A3 and ABS modulator-control unit 25P connector terminal No. 1.





Is there continuity?

YES -

Go to step 10.

NO -

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

10. Check for continuity between ECM/PCM connector terminal A3 and EPS control unit connector A (11P) terminal No. 5.





Is there continuity?

YES -

Go to step 11.

NO -

Repair an open in the wire between the ECM/PCM (A3) and the EPS control unit.

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





Is there continuity?

YES -

- With VSA system: Go to step 12.
- With ABS: Go to step 13.

NO -

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

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





Is there continuity?

YES -

Go to step 14.

NO -

Repair an open in the wire between the ECM/PCM (A4) and the VSA modulator-control unit.

13. Check for continuity between ECM/PCM connector terminal A4 and ABS modulator-control unit 25P connector terminal No. 17.





Is there continuity?

YES -

Go to step 14.

NO -

Repair an open in the wire between the ECM/PCM (A4) and the ABS modulator-control unit.

14. Check for continuity between ECM/PCM connector terminal A4 and EPS control unit connector A (11P) terminal No. 3.





Is there continuity?

YES -

Go to step 15.

NO -

Repair an open in the wire between the ECM/PCM (A4) and the EPS control unit.

15. Reconnect the gauge control module 32P connector.

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





Is there about 2.34-2.86 kOhms?

YES -

- With VSA system: Go to step 17.
- With ABS: Go to step 23.

NO -

Substitute a known-good gauge control module Service and Repair, then reconnect ECM/PCM connector A. If the HDS identifies the vehicle, replace the original gauge control module Service and Repair.

17. Disconnect the gauge control module 32P connector.

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

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





Is there about 108-132 Ohms?

YES -

Go to step 20.

NO -

Substitute a known-good VSA modulator-control unit, then reconnect ECM/PCM connector A. If the HDS identifies the vehicle, replace the original VSA modulator-control unit.

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

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

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





Is there about 2.34-2.86 kOhms?

YES -

Go to step 26.

NO -

Substitute a known-good yaw rate-lateral acceleration sensor, then reconnect ECM/PCM connector A. If the HDS identifies the vehicle, replace the original yaw rate-lateral acceleration sensor.

23. Disconnect the gauge control module 32P connector.

24. Reconnect the ABS modulator-control unit 25P connector.

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





Is there about 108-132 Ohms?

YES -

Go to step 26.

NO -

Substitute a known-good ABS modulator-control unit, then reconnect ECM/PCM connector A. If the HDS identifies the vehicle, replace the original ABS modulator-control unit.

26. Disconnect the yaw rate/lateral acceleration sensor 5P connector (with VSA system) or the ABS modulator-control unit 25P connector (with ABS).

27. Reconnect EPS control unit connector A (11P).

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





Is there about 2.34-2.86 kOhms?

YES -

Go to step 29.

NO -

Substitute a known-good EPS control unit Service and Repair, then reconnect ECM/PCM connector A. If the HDS identifies the vehicle, replace the original EPS control unit Service and Repair.

29. Disconnect EPS control unit connector A (11P).

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

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





Is there about 2.34-2.86 kOhms?

YES -

Go to step 32.

NO -

Substitute a known-good SRS unit Service and Repair, then reconnect ECM/PCM connector A. If the HDS identifies the vehicle, replace the original SRS unit Service and Repair.

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

33. Reconnect the TPMS control unit 20P connector.

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





Is there about 2.34-2.86 kOhms?

YES -

- '12 model with navigation system: Go to step 35.
- Except '12 model with navigation system: Update the ECM/PCM if it does not have the latest software ECM/PCM Update, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM Service and Repair.

NO -

Substitute a known-good TPMS control unit Service and Repair, then reconnect ECM/PCM connector A. If the HDS identifies the vehicle, replace the original TPMS control unit Service and Repair.

35. Disconnect the TPMS control unit 20P connector.

36. Reconnect audio-navigation unit connector D (20P).

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





Is there about 2.34-2.86 kOhms?

YES -

Update the ECM/PCM if it does not have the latest software ECM/PCM Update, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM Service and Repair.

NO -

Substitute a known-good audio-navigation unit, then reconnect ECM/PCM connector A. If the HDS identifies the vehicle, replace the original audio-navigation unit.

38. Disconnect these connectors:

- Gauge control module 32P Service and Repair.
- VSA modulator-control unit 36P (with VSA system).
- Yaw rate-lateral acceleration sensor 5P (with VSA system).
- ABS modulator-control unit 25P (with ABS).
- EPS control unit A (11P) Service and Repair.
- SRS unit A (39P) Service and Repair.
- TPMS control unit 20P Service and Repair.
- Audio-navigation unit D (20P) Audio-Navigation Unit Removal/Installation (With Navigation)

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





Is there continuity?

YES -

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

NO -

Go to step 40.

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





Is there continuity?

YES -

Repair a short in the wire between ECM/PCM terminal A4 and the gauge control module, the VSA modulator-control unit (with VSA system), the yaw rate-lateral acceleration sensor (with VSA system), the ABS modulator-control unit (with ABS), the EPS control unit, the SRS unit, the TPMS control unit, or the DLC.

NO -

Go to step 41.

41. Reconnect all connectors.

42. Connect the HDS to the DLC.

43. Disconnect the gauge control module 32P connector.

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

Does the HDS identify the vehicle?

YES -

Replace the gauge control module Service and Repair.

NO -

- With VSA system: Go to step 45.
- With ABS: Go to step 53.

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

46. Reconnect the gauge control module 32P connector.

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

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

Does the HDS identify the vehicle?

YES -

Replace the VSA modulator-control unit.

NO -

Go to step 49.

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

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

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

52. 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.

NO -

Go to step 57.

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

54. Reconnect the gauge control module 32P connector.

55. Disconnect the ABS modulator-control unit 25P connector.

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

Does the HDS identify the vehicle?

YES -

Replace the ABS modulator-control unit.

NO -

Go to step 57.

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

58. Reconnect the yaw rate-lateral acceleration sensor 5P connector (with VSA system) or the ABS modulator-control unit (with ABS).

59. Disconnect EPS control unit connector A (11P).

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

Does the HDS identify the vehicle?

YES -

Replace the EPS control unit Service and Repair.

NO -

Go to step 61.

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

62. Reconnect EPS control unit connector A (11P).

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

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

Does the HDS identify the vehicle?

YES -

Replace the SRS unit Service and Repair.

NO -

Go to step 65.

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

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

67. Disconnect the TPMS control unit 20P connector.

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

Does the HDS identify the vehicle?

YES -

Replace the TPMS control unit Service and Repair.

NO -

- '12 model with navigation system: Go to step 69.
- Except '12 model with navigation system: Update the ECM/PCM if it does not have the latest software ECM/PCM Update, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM Service and Repair.

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

70. Reconnect the TPMS control unit 20P connector.

71. Disconnect audio-navigation unit connector D (20P).

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

Does the HDS identify the vehicle?

YES -

Replace the audio-navigation unit Audio-Navigation Unit Removal/Installation (With Navigation).

NO -

Update the ECM/PCM if it does not have the latest software ECM/PCM Update, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM Service and Repair.

pro multis · About Operation CHARM