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 connector A (44P), then disconnect the HDS.

4. Measure the resistance between ECM connector terminals A36 and A37.

Is there about 88-116 Ohms?
YES - Go to step 37.

NO - Go to step 5.






5. Disconnect the gauge control module (tach) 36P connector. Gauge Control Module Replacement

6. Disconnect the ABS modulator-control unit 25P connector (without VSA) Service and Repair or the VSA modulator-control unit 37P connector (with VSA) Service and Repair and the yaw rate-lateral acceleration sensor 4P connector (with VSA). Service and Repair

7. Disconnect the SRS unit 28P connector. SRS Unit Replacement

8. Disconnect EPS control unit connector D (28P). Service and Repair

9. With TPMS: Disconnect the TPMS control unit 20P connector. Service and Repair

10. Check for continuity between ECM connector terminals A36 and A37.

Is there continuity?
YES - Repair short in the wires between ECM connector terminals A36 and A37.

NO - Go to step 11.






11. Check for continuity between ECM connector terminal A36 and gauge control module (tach) 36P connector terminal No. 1.

Is there continuity?
YES -
- With VSA: Go to step 12.

- Without VSA: Go to step 13.


NO - Repair open in the wire between the ECM (A36) and the gauge control module (tach).






12. Check for continuity between ECM connector terminal A36 and VSA modulator-control unit 37P connector terminal No. 15.

Is there continuity?
YES - Go to step 13.

NO - Repair open in the wire between the ECM (A36) and the VSA modulator-control unit.






13. Check for continuity between ECM connector terminal A36 and EPS control unit connector D (28P) terminal No. 1.

Is there continuity?
YES - Go to step 14.

NO - Repair open in the wire between the ECM (A36) and the EPS control unit.






14. Check for continuity between ECM connector terminal A37 and gauge control module (tach) 36P connector terminal No. 19.

Is there continuity?
YES -
- With VSA: Go to step 15.

- Without VSA: Go to step 16.


NO - Repair open in the wire between the ECM (A37) and the gauge control module (tach).






15. Check for continuity between ECM connector terminal A37 and VSA modulator-control unit 37P connector terminal No. 1.

Is there continuity?
YES - Go to step 16.

NO - Repair open in the wire between the ECM (A37) and the VSA modulator-control unit.






16. Check for continuity between ECM connector terminal A37 and EPS control unit connector D (28P) terminal No. 15.

Is there continuity?
YES - Go to step 17.

NO - Repair open in the wire between the ECM (A37) and the EPS control unit.






17. Reconnect the gauge control module (tach) 36P connector.

18. Measure the resistance between ECM connector terminals A36 and A37.

Is there about 108-132 Ohms?
YES -
- Without VSA: Go to step 19.

- With VSA: Go to step 22.


NO - Substitute a known-good gauge control module (tach), Gauge Control Module Replacement then reconnect ECM connector A (44P). If the HDS identifies the vehicle, replace the original gauge control module (tach). Gauge Control Module Replacement






19. Disconnect the gauge control module (tach) 36P connector.

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

21. Measure the resistance between ECM connector terminals A36 and A37.

Is there about 2.34-2.86 kOhms?
YES - Go to step 28.

NO - Substitute a known-good ABS modulator-control unit, Service and Repair then reconnect ECM connector A (44P). If the HDS identifies the vehicle, replace the original ABS modulator-control unit. Service and Repair






22. Disconnect the gauge control module (tach) 36P connector.

23. Reconnect the VSA modulator-control unit 37P connector.

24. Measure the resistance between ECM connector terminals A36 and A37.

Is there about 2.34-2.86 kOhms?
YES - Go to step 25.

NO - Substitute a known-good VSA modulator-control unit, Service and Repair then reconnect ECM connector A (44P). If the HDS identifies the vehicle, replace the original VSA modulator-control unit. Service and Repair






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

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

27. Measure the resistance between ECM connector terminals A36 and A37.

Is there about 2.34-2.86 kOhms?
YES - Go to step 28.

NO - Substitute a known-good yaw rate-lateral acceleration sensor, Service and Repair then reconnect ECM connector A (44P). If the HDS identifies the vehicle, replace the original yaw rate-lateral acceleration sensor. Service and Repair






28. Disconnect the ABS modulator-control unit 25P connector (or the yaw rate-lateral acceleration sensor 5P connector).

29. Reconnect SRS unit connector A (28P).

30. Measure the resistance between ECM connector terminals A36 and A37.

Is there about 2.34-2.86 kOhms?
YES - Go to step 31.

NO - Substitute a known-good SRS unit, SRS Unit Replacement then reconnect ECM connector A (44P). If the HDS identifies the vehicle, replace the original SRS unit. SRS Unit Replacement






31. Disconnect SRS unit connector A (28P).

32. Reconnect EPS control unit connector D (28P).

33. Measure the resistance between ECM connector terminals A36 and A37.

Is there about 2.34-2.86 kOhms?
YES -
- With TPMS: Go to step 34.

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


NO - Substitute a known-good EPS control unit, Service and Repair then reconnect ECM connector A (44P). If the HDS identifies the vehicle, replace the original EPS control unit. Service and Repair






34. Disconnect EPS control unit connector D (28P).

35. Reconnect the TPMS control unit 20P connector.

36. Measure the resistance between ECM connector terminals A36 and A37.

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

NO - Substitute a known-good TPMS control unit, Service and Repair then reconnect ECM connector A (44P). If the HDS identifies the vehicle, replace the original TPMS control unit. Service and Repair






37. Disconnect the gauge control module (tach) 36P connector. Gauge Control Module Replacement

38. Disconnect the ABS modulator-control unit 25P connector (without VSA) Service and Repair or the VSA modulator-control unit 37P connector (with VSA) Service and Repair and the yaw rate-lateral acceleration sensor 5P connector (with VSA). Service and Repair

39. Disconnect SRS unit connector A (28P). SRS Unit Replacement

40. Disconnect EPS control unit connector D (28P). Service and Repair

41. With TPMS: Disconnect the TPMS control unit 20P connector. Service and Repair

42. Check for continuity between ECM connector terminal A36 and body ground.

Is there continuity?
YES - Repair short in the wire between ECM connector terminal A36 and the gauge control module, the ABS modulator-control unit (without VSA), the VSA modulator-control unit (with VSA), the yaw rate-lateral acceleration sensor (with VSA), the SRS unit, the EPS control unit, TPMS control unit (with TPMS), or the DLC.

NO - Go to step 51.






43. Check for continuity between ECM connector terminal A37 and body ground.

Is there continuity?
YES - Repair short in the wire between ECM connector terminal A37 and the gauge control module, the ABS modulator-control unit (without VSA), the VSA modulator-control unit (with VSA), the yaw rate-lateral acceleration sensor (with VSA), the SRS unit, the EPS control unit, the TPMS control unit (with TPMS), or the DLC.

NO - Go to step 44.






44. Reconnect all connectors.

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

46. Disconnect the gauge control module (tach) 36P connector.

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

Does the HDS identify the vehicle?
YES - Replace the gauge control module (tach). Gauge Control Module Replacement

NO -
- Without VSA: Go to step 48.

- With VSA: Go to step 52.



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

49. Reconnect the gauge control module (tach) 36P connector.

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

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

Does the HDS identify the vehicle?
YES - Replace the ABS modulator-control unit. Service and Repair

NO - Go to step 60.


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

53. Reconnect the gauge control module (tach) 36P connector.

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

55. 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 56.


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

57. Reconnect the VSA modulator-control unit 37P connector.

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

59. 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 60.


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

61. Reconnect the ABS modulator-control unit 25P connector (or yaw rate-lateral acceleration sensor 5P connector).

62. Disconnect SRS unit connector A (28P).

63. 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 64.


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

65. Reconnect SRS unit connector A (28P).

66. Disconnect EPS control unit connector D (28P).

67. 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 -
- With TPMS: Go to step 68.

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



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

69. Reconnect EPS control unit connector D (28P).

70. Disconnect the TPMS control unit 20P connector.

71. 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 - Reconnect all connectors, then update the ECM if it does not have the latest software, ECM/PCM Update or substitute a known-good ECM, Reading and Clearing Diagnostic Trouble Codes then recheck. If the HDS identifies the vehicle and the ECM was updated, troubleshooting is complete. If the HDS identifies the vehicle and the ECM was substituted, replace the original ECM. Service and Repair