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.

Is there about 81-99 Ohms?
YES - Go to step 36.

NO - Go to step 5.






5. Disconnect these connectors:
- Gauge control module 32P. Service and Repair

- VSA modulator-control unit 47P. Service and Repair

- EPS control unit 28P connector. Service and Repair

- Yaw rate-lateral acceleration sensor 5P. Service and Repair

- SRS unit A (39P). SRS Unit Replacement

- TPMS control unit 20P. Service and Repair

- Navigation unit B (32P) (with navigation). Service and Repair

- AcuraLink control unit (XM receiver) connector A (32P) (USA model with navigation). AcuraLink Control Unit (XM Receiver) Removal/Installation

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

Is there continuity?
YES - Repair 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 32P connector terminal No. 22.

Is there continuity?
YES - Go to step 8.

NO - Repair 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 47P connector terminal No. 12.

Is there continuity?
YES - Go to step 9.

NO - Repair open in the wire between the PCM (A48) and the VSA modulator-control unit.






9. Check for continuity between PCM connector terminal A48 and EPS control unit connector D (28P) terminal No. 1.

Is there continuity?
YES - Go to step 10.

NO - Repair open in the wire between the PCM (A48) and the EPS control unit.






10. Check for continuity between PCM connector terminal A49 and gauge control module 32P connector terminal No. 21.

Is there continuity?
YES - Go to step 11.

NO - Repair open in the wire between the PCM (A49) and the gauge control module.






11. Check for continuity between PCM connector terminal A49 and VSA modulator-control unit 47P connector terminal No. 13.

Is there continuity?
YES - Go to step 12.

NO - Repair open in the wire between the PCM (A49) and the VSA modulator-control unit.






12. Check for continuity between PCM connector terminal A49 and EPS control unit connector D (28P) terminal No. 15.

Is there continuity?
YES - Go to step 13.

NO - Repair open in the wire between the PCM (A49) and the EPS control unit.






13. Reconnect the gauge control module 32P connector.

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

Is there about 2.34-2.86 kOhms?
YES - Go to step 15.

NO - Substitute a known-good gauge control module, Service and Repair and reconnect PCM connector A (49P). If the HDS identifies the vehicle, replace the original gauge control module. Service and Repair






15. Disconnect the gauge control module 32P connector.

16. Reconnect the VSA modulator-control unit 47P connector.

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

Is there about 108-132 Ohms?
YES - Go to step 18.

NO - Substitute a known-good VSA modulator-control unit, Service and Repair and reconnect PCM connector A (49P). If the HDS identifies the vehicle, replace the original VSA modulator-control unit. Service and Repair






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

19. Reconnect the EPS control unit 28P connector.

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

Is there about 2.34-2.86 kOhms?
YES - Go to step 21.

NO - Substitute a known-good EPS control unit, Service and Repair and reconnect PCM connector A (49P). If the HDS identifies the vehicle, replace the original EPS control unit. Service and Repair






21. Disconnect the EPS control unit 28P connector.

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

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

Is there about 2.16-2.64 kOhms?
YES - Go to step 24.

NO - Substitute a known-good yaw rate-lateral acceleration sensor, Service and Repair and reconnect PCM connector A (49P). If the HDS identifies the vehicle, replace the original yaw rate-lateral acceleration sensor. Service and Repair






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

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

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

Is there about 2.34-2.86 kOhms?
YES - Go to step 27.

NO - Substitute a known-good SRS unit, SRS Unit Replacement and reconnect PCM connector A (49P). If the HDS identifies the vehicle, replace the original SRS unit. SRS Unit Replacement






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

28. Reconnect the TPMS control unit 20P connector.

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

Is there about 2.34-2.86 kOhms?
YES -
- With navigation: Go to step 30.

- Without navigation: Update the PCM if it does not have the latest software ECM/PCM Update, or substitute a known-good PCM, Reading and Clearing Diagnostic Trouble Codes then recheck. If the HDS identifies the vehicle and the PCM was updated, troubleshooting is complete. If the HDS identifies the vehicle and the PCM was substituted, replace the original PCM. Service and Repair


NO - Substitute a known-good TPMS control unit, Service and Repair and reconnect PCM connector A (49P). If the HDS identifies the vehicle, replace the original TPMS control unit. Service and Repair






30. Disconnect TPMS control unit 20P connector.

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

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

Is there about 2.34-2.86 kOhms?
YES -
- USA model with navigation: Go to step 33.

- Canada model without navigation: Update the PCM if it does not have the latest software, ECM/PCM Update or substitute a known-good PCM Reading and Clearing Diagnostic Trouble Codes, then recheck. If the HDS identifies the vehicle and the PCM was updated, troubleshooting is complete. If the HDS identifies the vehicle and the PCM was substituted, replace the original PCM. Service and Repair


NO - Substitute a known-good navigation unit, Service and Repair then reconnect PCM connector A (49P). If the HDS identifies the vehicle, replace the original navigation unit. Service and Repair






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

34. Reconnect AcuraLink control unit connector A (32P).

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

Is there about 2.34-2.86 kOhms?
YES - Update the PCM if it does not have the latest software, ECM/PCM Update or substitute a known-good PCM Reading and Clearing Diagnostic Trouble Codes, then recheck. If the HDS identifies the vehicle and the PCM was updated, troubleshooting is complete. If the HDS identifies the vehicle and the PCM was substituted, replace the original PCM. Service and Repair

NO - Substitute a known-good AcuraLink control unit, AcuraLink Control Unit (XM Receiver) Removal/Installation then reconnect PCM connector A (49P). If the HDS identifies the vehicle, replace the original AcuraLink control unit (XM receiver). AcuraLink Control Unit (XM Receiver) Removal/Installation






36. Disconnect these connectors:
- Gauge control module 32P. Service and Repair

- VSA modulator-control unit 47P. Service and Repair

- EPS control unit 28P connector. Service and Repair

- Yaw rate-lateral acceleration sensor 5P. Service and Repair

- SRS unit A (39P). SRS Unit Replacement

- TPMS control unit 20P. Service and Repair

- Navigation unit B (32P) (with navigation). Service and Repair

- AcuraLink control unit (XM receiver) connector A (32P) (USA model with navigation). AcuraLink Control Unit (XM Receiver) Removal/Installation

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

Is there continuity?
YES - Repair short in the wire between the PCM (A48) and the gauge control module, the VSA modulator-control unit, the EPS control unit, the yaw rate-lateral acceleration sensor, the SRS unit, the TPMS control unit, the navigation unit, the AcuraLink control unit (XM receiver) (USA model with navigation), or the DLC.

NO - Go to step 38.






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

Is there continuity?
YES - Repair short in the wire between the PCM (A49) and the gauge control module, the VSA modulator-control unit, the EPS control unit, the yaw rate-lateral acceleration sensor, the SRS unit, the TPMS control unit, the navigation unit, the AcuraLink control unit (XM receiver) (USA model with navigation), or the DLC.

NO - Go to step 39.






39. Reconnect all connectors.

40. Connect the HDS to the DLC. Reading and Clearing Diagnostic Trouble Codes

41. Disconnect the gauge control module 32P connector.

42. 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 43.


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

44. Reconnect the gauge control module 32P connector.

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

46. 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 47.


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

48. Reconnect the VSA modulator-control unit 47P connector.

49. Disconnect the EPS control unit 28P connector.

50. 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 51.


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

52. Reconnect the EPS control unit 28P connector.

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

54. 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. Service and Repair

NO - Go to step 55.


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

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

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

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

Does the HDS identify the vehicle?
YES - Replace the SRS unit. SRS Unit Replacement

NO - Go to step 59.


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

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

61. Disconnect the TPMS control unit 20P connector.

62. 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 -
- With navigation: Go to step 63.

- Without navigation: Reconnect all connectors, then update the PCM if it does not have the latest software, ECM/PCM Update or substitute a known-good PCM, Reading and Clearing Diagnostic Trouble Codes then recheck. If the HDS identifies the vehicle and the PCM was updated, troubleshooting is complete. If the HDS identifies the vehicle and the PCM was substituted, replace the original PCM. Service and Repair



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

64. Reconnect TPMS control unit 20P connector.

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

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

Does the HDS identify the vehicle?
YES - Replace the navigation unit. Service and Repair

NO -
- USA model with AcuraLink: Go to step 67.

- Canada model without AcuraLink: Reconnect all connectors, then update the PCM if it does not have the latest software, ECM/PCM Update or substitute a known-good PCM, Reading and Clearing Diagnostic Trouble Codes then recheck. If the HDS identifies the vehicle and the PCM was updated, troubleshooting is complete. If the HDS identifies the vehicle and the PCM was substituted, replace the original PCM. Service and Repair



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

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

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

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

Does the HDS identify the vehicle?
YES - Replace the AcuraLink control unit (XM receiver). AcuraLink Control Unit (XM Receiver) Removal/Installation

NO - Reconnect all connectors, then update the PCM if it does not have the latest software, ECM/PCM Update or substitute a known-good PCM, Reading and Clearing Diagnostic Trouble Codes then recheck. If the HDS identifies the vehicle and the PCM was updated, troubleshooting is complete. If the HDS identifies the vehicle and the PCM was substituted, replace the original PCM. Service and Repair