F-CAN Circuit Troubleshooting
F-CAN Circuit Troubleshooting1. Turn the ignition switch to LOCK (0).
2. Jump the SCS line with the HDS.
3. Disconnect ECM/PCM connector A (49P).
4. Measure resistance between ECM/PCM connector terminals A3 and A4.
Is there about 88 - 111 ohms?
YES - Go to step 39.
NO - Go to step 5.
5. Disconnect these connectors:
- Gauge control module 32P.
- VSA modulator-control unit 36P.
- Yaw rate-lateral acceleration sensor 5P.
- SRS unit A (28P).
- TPMS control unit (20P).
- Navigation unit A (32P) (if equipped).
6. Check for continuity between ECM/PCM connector terminals A3 and A4.
Is there continuity?
YES - Repair short in the wires between ECM/PCM connector terminals A3 and A4.
NO - Go to step 7.
7. Connect ECM/PCM connector terminal A3 to body ground with a jumper wire.
8. Check for continuity between gauge control module 32P connector terminal No. 30 and body ground.
Is there continuity?
YES - Go to step 9.
NO - Repair open in the wire between the ECM/PCM (A3) and the gauge control module.
9. Check for continuity between VSA modulator-control unit 36P connector terminal No. 14 and body ground.
Is there continuity?
YES - Go to step 10.
NO - Repair open in the wire between the ECM/PCM (A3) and the VSA modulator-control unit.
10. Check for continuity between yaw rate-lateral acceleration sensor 5P connector terminal No. 3 and body ground.
Is there continuity?
YES - Go to step 11.
NO - Repair open in the wire between the ECM/PCM (A3) and the yaw rate-lateral acceleration sensor.
11. Check for continuity between SRS unit connector A (28P) terminal No. 17 and body ground.
Is there continuity?
YES - Go to step 12.
NO - Repair open in the wire between the ECM/PCM (A3) and the SRS unit.
12. Check for continuity between TPMS control unit 20P connector terminal No. 1 and body ground.
Is there continuity?
YES -
- With navigation system: Go to step 13.
- Without navigation system: Go to step 14.
NO - Repair open in the wire between the ECM/PCM (A3) and the TPMS control unit.
13. Check for continuity between navigation unit connector A (32P) terminal No. 8 and body ground.
Is there continuity?
YES - Go to step 14.
NO - Repair open in the wire between the ECM/PCM (A3) and the navigation unit.
14. Connect ECM/PCM connector terminal A4 to body ground with a jumper wire.
15. Check for continuity between gauge control module 32P connector terminal No. 29 and body ground.
Is there continuity?
YES - Go to step 16.
NO - Repair open in the wire between the ECM/PCM (A4) and the gauge control module.
16. Check for continuity between VSA modulator-control unit 36P connector terminal No. 1 and body ground.
Is there continuity?
YES - Go to step 17.
NO - Repair open in the wire between the ECM/PCM (A4) and the VSA modulator-control unit.
17. Check for continuity between yaw rate-lateral acceleration sensor 5P connector terminal No. 4 and body ground.
Is there continuity?
YES - Go to step 18.
NO - Repair open in the wire between the ECM/PCM (A4) and the yaw rate-lateral acceleration sensor.
18. Check for continuity between SRS unit connector A (28P) terminal No. 16 and body ground.
Is there continuity?
YES - Go to step 19.
NO - Repair open in the wire between the ECM/PCM (A4) and the SRS unit.
19. Check for continuity between TPMS control unit 20P connector terminal No. 11 and body ground.
Is there continuity?
YES -
- With navigation system: Go to step 20.
- Without navigation system: Go to step 21.
NO - Repair open in the wire between the ECM/PCM (A4) and the TPMS control unit.
20. Check for continuity between navigation unit connector A (32P) terminal No. 24 and body ground.
Is there continuity?
YES - Go to step 21.
NO - Repair open in the wire between the ECM/PCM (A4) and the navigation unit.
21. Remove the jumper wire from the ECM/PCM connector.
22. Reconnect the gauge control module 32P connector.
23. Measure resistance between ECM/PCM connector terminals A3 and A4.
Is there about 2.34 - 2.86 kohms?
YES - Go to step 24.
NO - Substitute a known-good gauge control module, and reconnect ECM/PCM connector A. If the HDS identifies the vehicle, replace the original gauge control module.
24. Disconnect the gauge control module 32P connector.
25. Reconnect the VSA modulator-control unit 36P connector.
26. Measure resistance between ECM/PCM connector terminals A3 and A4.
Is there about 108 - 132 ohms?
YES - Go to step 27.
NO - Substitute a known-good VSA modulator-control unit, and reconnect ECM/PCM connector A. If the HDS identifies the vehicle, replace the original VSA modulator-control unit.
27. Disconnect the VSA modulator-control unit 36P connector.
28. Reconnect the yaw rate-lateral acceleration sensor 5P connector.
29. Measure resistance between ECM/PCM connector terminals A3 and A4.
Is there about 2.34 - 2.86 kohms?
YES - Go to step 30.
NO - Substitute a known-good yaw rate-lateral acceleration sensor, and reconnect ECM/PCM connector A. If the HDS identifies the vehicle, replace the original yaw rate-lateral acceleration sensor.
30. Disconnect the yaw-rate lateral acceleration sensor 5P connector.
31. Reconnect SRS unit connector A (28P).
32. Measure resistance between ECM/PCM connector terminals A3 and A4.
Is there about 2.34 - 2.86 kohms?
YES - Go to step 33.
NO - Substitute a known-good SRS unit, and reconnect ECM/PCM connector A. If the HDS identifies the vehicle, replace the original SRS unit.
33. Disconnect SRS unit connector A (28P).
34. Reconnect the TPMS control unit 20P connector.
35. Measure resistance between ECM/PCM connector terminals A3 and A4.
Is there about 2.34 - 2.86 kohms?
YES -
- With navigation system: Go to step 36.
- Without navigation system: Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the HDS identifies the vehicle with a known-good ECM/PCM, replace the original ECM/PCM.
NO - Substitute a known-good TPMS control unit, and reconnect ECM/PCM connector A. If the HDS identifies the vehicle, replace the original TPMS control unit.
36. Disconnect the TPMS control unit 20P connector.
37. Reconnect navigation unit connector A (32P).
38. Measure 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, or substitute a known-good ECM/PCM, then recheck. If the HDS identifies the vehicle with a known-good ECM/PCM, replace the original ECM/PCM.
NO - Substitute a known-good navigation unit, and reconnect ECM/PCM connector A. If the HDS identifies the vehicle, replace the original navigation unit.
39. Disconnect these connectors:
- Gauge control module 32P.
- VSA modulator-control unit 36P.
- Yaw rate-lateral acceleration sensor 5P.
- SRS unit A (28P).
- TPMS control unit (20P).
- Navigation unit A (32P) (if equipped).
40. Check for continuity between ECM/PCM connector terminal A3 and body ground.
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 41.
41. Check for continuity between ECM/PCM connector terminal A4 and body ground.
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 DLC.
NO - Go to step 42.
42. Reconnect all connectors.
43. Connect the HDS to the DLC.
44. Disconnect the gauge control module 32P connector.
45. Turn the ignition switch to ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES - Replace the gauge control module.
NO - Go to step 46.
46. Turn the ignition switch to LOCK (0).
47. Reconnect the gauge control module 32P connector.
48. Disconnect the VSA modulator-control unit 36P connector.
49. Turn the ignition switch to ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES - Replace the VSA control unit.
NO - Go to step 50.
50. Turn the ignition switch to LOCK (0).
51. Reconnect the VSA modulator-control unit 36P connector.
52. Disconnect the yaw rate-lateral acceleration sensor 5P connector.
53. 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 54.
54. Turn the ignition switch to LOCK (0).
55. Reconnect the yaw rate-lateral acceleration sensor 5P connector.
56. Disconnect SRS unit connector A (28P).
57. Turn the ignition switch to ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES - Replace the SRS unit.
NO - Go to step 58.
58. Turn the ignition switch to LOCK (0).
59. Reconnect SRS unit connector A (28P).
60. Disconnect the TPMS control unit 20P connector.
61. Turn the ignition switch to ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES - Replace the TPMS control unit.
NO -
- With navigation system: Go to step 62.
- Without navigation system: Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the HDS identifies the vehicle with a known-good ECM/PCM, replace the original ECM/PCM.
62. Turn the ignition switch to LOCK (0).
63. Reconnect the TPMS control unit 20P connector.
64. Disconnect navigation unit connector A (32P).
65. Turn the ignition switch to ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES - Replace the navigation unit.
NO - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the HDS identifies the vehicle with a known-good ECM/PCM, replace the original ECM/PCM.