Operation CHARM: Car repair manuals for everyone.
Home >> Acura >> 2012 >> MDX V6-3.7L >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Information Bus >> Testing and Inspection >> Component Tests and General Diagnostics >> F-CAN Circuit Troubleshooting
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la
If it fails: lemon-manuals.org.ua

Or, hide this message: temporarily or permanently

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 PCM connector A (49P).

4. Measure the resistance between PCM connector terminals A48 and A49, then compare your reading to the model/trim level listed the table below.

Vehicles with active damper:





Vehicles without active damper:









Is the resistance OK?

YES -

Go to step 20.

NO -

Go to step 5.

5. Disconnect these connectors:

- Gauge control module connector A (12P) Service and Repair.
- VSA modulator-control unit 46P connector Service and Repair.
- Yaw rate-lateral/longitudinal acceleration sensor 4P connector Service and Repair.
- Steering angle sensor 5P connector Service and Repair.
- SRS unit connector A (39P) Service and Repair.
- TPMS control unit 20P connector Service and Repair.
- Active damper control unit connector B (14P) (with active damper) Service and Repair.
- SH-AWD control unit connector A (20P) Service and Repair.
- ACC unit 20P connector (with ACC) Service and Repair.
- E-pretensioner unit connector B (14P) (with ACC) Removal and Replacement.
- AcuraLink control unit connector A (32P) (USA model with AcuraLink) AcuraLink Control Unit (XM Receiver) Removal/Installation.

6. Check for continuity between PCM connector terminals A48 and A49.





Is there continuity?

YES -

Repair a short in the wires between PCM connector terminals A48 and A49.

NO -

Go to step 7.

7. Check for continuity between PCM connector terminal A48 and gauge control module connector A (12P) terminal No. 12.





Is there continuity?

YES -

Go to step 8.

NO -

Repair an open in the wire between the PCM (A48) and the gauge control module.

8. Check for continuity between PCM connector terminal A48 and VSA modulator-control unit 46P connector terminal No. 39.





Is there continuity?

YES -

Go to step 9.

NO -

Repair an open in the wire between the PCM (A48) and the VSA modulator-control unit.

9. Check for continuity between PCM connector terminal A48 and SH-AWD control unit connector A (20P) terminal No. 10.





Is there continuity?

YES -

- With ACC: Go to step 10.
- Without ACC: Go to step 11.

NO -

Repair an open in the wire between the PCM (A48) and the SH-AWD control unit.

10. Check for continuity between PCM connector terminal A48 and ACC unit 20P connector terminal No. 10.





Is there continuity?

YES -

Go to step 11.

NO -

Repair an open in the wire between the PCM (A48) and the ACC unit.

11. Check for continuity between PCM connector terminal A49 and gauge control module connector A (12P) terminal No. 6.





Is there continuity?

YES -

Go to step 12.

NO -

Repair an open in the wire between the PCM (A49) and the gauge control module.

12. Check for continuity between PCM connector terminal A49 and VSA modulator-control unit 46P connector terminal No. 38.





Is there continuity?

YES -

Go to step 13.

NO -

Repair an open in the wire between the PCM (A49) and the VSA modulator-control unit.

13. Check for continuity between PCM connector terminal A49 and SH-AWD control unit connector A (20P) terminal No. 20.





Is there continuity?

YES -

- With ACC: Go to step 14.
- Without ACC: Go to step 15.

NO -

Repair an open in the wire between the PCM (A49) and the SH-AWD control unit.

14. Check for continuity between PCM connector terminal A49 and ACC unit 20P connector terminal No. 20.





Is there continuity?

YES -

Go to step 15.

NO -

Repair an open in the wire between the PCM (A49) and the ACC unit.

15. Reconnect the VSA modulator-control unit 46P connector.

16. Measure the resistance between PCM connector terminals A48 and A49.





Is there about 108-132 Ohms?

YES -

Go to step 17.

NO -

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

17. Disconnect the VSA modulator-control unit 46P connector.

18. Reconnect SH-AWD control unit connector A (20P).

19. Measure the resistance between PCM connector terminals A48 and A49.





Is there about 108-132 Ohms?

YES -

Go to step 20.

NO -

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

20. Disconnect these connectors:

- Gauge control module connector A (12P) Service and Repair.
- VSA modulator-control unit 46P connector Service and Repair.
- Yaw rate-lateral/longitudinal acceleration sensor 4P connector Service and Repair.
- Steering angle sensor 5P connector Service and Repair.
- SRS unit connector A (39P) Service and Repair.
- TPMS control unit 20P connector Service and Repair.
- Active damper control unit connector B (14P) (with active damper) Service and Repair.
- SH-AWD control unit connector A (20P) Service and Repair.
- ACC unit 20P connector (with ACC) Service and Repair.
- E-pretensioner unit connector B (14P) (with ACC) Removal and Replacement.
- AcuraLink control unit connector A (32P) (USA model with AcuraLink) AcuraLink Control Unit (XM Receiver) Removal/Installation.

21. Check for continuity between PCM connector terminal A48 and body ground.





Is there continuity?

YES -

Repair a short in the wire between the PCM (A48) and the gauge control module, the VSA modulator-control unit, the SRS unit, the TPMS control unit, the yaw rate-lateral/longitudinal acceleration sensor, the steering angle sensor, the SH-AWD control unit, the active damper control unit (with active damper), the AcuraLink control unit (with AcuraLink), the ACC unit (with ACC), the E-pretensioner unit (with ACC), or the DLC.

NO -

Go to step 22.

22. Check for continuity between PCM connector terminal A49 and body ground.





Is there continuity?

YES -

Repair a short in the wire between the PCM (A49) and the gauge control module, the VSA modulator-control unit, the SRS unit, the TPMS control unit, the yaw rate-lateral/longitudinal acceleration sensor, the steering angle sensor, the SH-AWD control unit, the active damper control unit (with active damper), the AcuraLink control unit (with AcuraLink), the ACC unit (with ACC), the E-pretensioner unit (ACC), or the DLC.

NO -

Go to step 23.

23. Reconnect all connectors.

24. Connect the HDS to the DLC.

25. Disconnect gauge control module connector A (12P).

26. 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 -

Go to step 27.

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

28. Reconnect gauge control module connector A (12P).

29. Disconnect the VSA modulator-control unit 46P connector.

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

Does the HDS identify the vehicle?

YES -

Replace the VSA modulator-control unit Service and Repair.

NO -

Go to step 31.

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

32. Reconnect the VSA modulator-control unit 46P connector.

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

34. 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 35.

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

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

37. Disconnect the TPMS control unit 20P connector.

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

Does the HDS identify the vehicle?

YES -

Replace TPMS control unit Service and Repair.

NO -

Go to step 39.

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

40. Reconnect the TPMS control unit 20P connector.

41. Disconnect the yaw rate-lateral/longitudinal acceleration sensor 4P 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/longitudinal acceleration sensor Service and Repair.

NO -

Go to step 43.

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

44. Reconnect the yaw rate-lateral/longitudinal acceleration sensor 4P connector.

45. Disconnect the steering angle sensor 5P connector.

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

Does the HDS identify the vehicle?

YES -

Replace the steering angle sensor Service and Repair.

NO -

- With active damper: Go to step 47.
- Without active damper: Go to step 51.

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

48. Reconnect the steering angle sensor 5P connector.

49. Disconnect active damper control unit connector B (14P).

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

Does the HDS identify the vehicle?

YES -

Replace the active damper control unit Service and Repair.

NO -

Go to step 51.

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

52. Reconnect the steering angle sensor 5P connector or active damper control unit connector B (14P).

53. Disconnect SH-AWD control unit connector A (20P)

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

Does the HDS identify the vehicle?

YES -

Replace the SH-AWD control unit Service and Repair.

NO -

- With ACC: Go to step 55.
- Without ACC: Update the PCM if it does not have the latest software PCM Update, or substitute a known-good PCM, then recheck. If the HDS identifies the vehicle with a known-good PCM, replace the original PCM Service and Repair.

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

56. Reconnect SH-AWD control unit connector A (20P).

57. Disconnect the ACC unit 20P connector.

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

Does the HDS identify the vehicle?

YES -

Replace the ACC unit Service and Repair.

NO -

Go to step 59.

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

60. Reconnect the ACC unit 20P connector.

61. Disconnect E-pretensioner unit connector B (14P).

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

Does the HDS identify the vehicle?

YES -

Replace the E-pretensioner unit Removal and Replacement.

NO -

- With AcuraLink: Go to step 63.
- Without AcuraLink: Update the PCM if it does not have the latest software PCM Update, or substitute a known-good PCM, then recheck. If the HDS identifies the vehicle with a known-good PCM, replace the original PCM Service and Repair.

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

64. Reconnect E-pretensioner unit connector B (14P).

65. Disconnect AcuraLink control unit connector A (32P).

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

Does the HDS identify the vehicle?

YES -

Replace the AcuraLink control unit AcuraLink Control Unit (XM Receiver) Removal/Installation.

NO -

Update the PCM if it does not have the latest software PCM Update, or substitute a known-good PCM, then recheck. If the HDS identifies the vehicle with a known-good PCM, replace the original PCM Service and Repair.

pro multis · About Operation CHARM