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 (44P), then disconnect the HDS.
4. Measure the resistance between PCM connector terminals A36 and A37.
Is there about 95-121 Ohms?
YES -
Go to step 23.
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 Service and Repair.
7. Disconnect SRS unit connector A (28P) SRS Unit Replacement.
8. With TPMS: Disconnect the TPMS control unit 20P connector Service and Repair.
9. Check for continuity between PCM connector terminals A36 and A37.
Is there continuity?
YES -
Repair short in the wires between PCM connector terminals A36 and A37.�
NO -
Go to step 10.
10. Check for continuity between PCM connector terminal A36 and gauge control module (tach) 36P connector terminal No. 1.
Is there continuity?
YES -
Go to step 11.
NO -
Repair open in the wire between the PCM (A36) and the gauge control module (tach).�
11. Check for continuity between PCM connector terminal A37 and gauge control module (tach) 36P connector terminal No. 19.
Is there continuity?
YES -
Go to step 12.
NO -
Repair open in the wire between the PCM (A37) and the gauge control module (tach).�
12. Reconnect the gauge control module (tach) 36P connector.
13. Measure the resistance between PCM connector terminals A36 and A37.
Is there about 108-132 Ohms?
YES -
Go to step 14.
NO -
Substitute a known-good gauge control module (tach) Gauge Control Module Replacement, then reconnect PCM connector A (44P). If the HDS identifies the vehicle, replace the original gauge control module (tach) Gauge Control Module Replacement.�
14. Disconnect the gauge control module (tach) 36P connector.
15. Reconnect the ABS modulator-control unit 25P connector.
16. Measure the resistance between PCM connector terminals A36 and A37.
Is there about 2.34-2.86 kOhms?
YES -
Go to step 17.
NO -
Substitute a known-good ABS modulator-control unit Service and Repair, then reconnect PCM connector A (44P). If the HDS identifies the vehicle, replace the original ABS modulator-control unit Service and Repair.�
17. Disconnect the ABS modulator-control unit 25P connector.
18. Reconnect SRS unit connector A (28P).
19. Measure the resistance between PCM connector terminals A36 and A37.
Is there about 2.34-2.86 kOhms?
YES -
Reconnect all connectors, then update the PCM if it does not have the latest software ECM/PCM Update, or substitute a known-good PCM, 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 -
- With TPMS: Go to step 20.
- Without TPMS: Substitute a known-good SRS unit SRS Unit Replacement, then reconnect PCM connector A (44P). If the HDS identifies the vehicle, replace the original SRS unit SRS Unit Replacement.�
20. Disconnect SRS unit connector A (28P).
21. Reconnect the TPMS control unit 20P connector.
22. Measure the resistance between PCM connector terminals A36 and A37.
Is there about 2.34-2.86 kOhms?
YES -
Reconnect all connectors, then update the PCM if it does not have the latest software ECM/PCM Update, or substitute a known-good PCM, 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, then reconnect PCM connector A (44P). If the HDS identifies the vehicle, replace the original TPMS control unit Service and Repair.�
23. Disconnect the gauge control module (tach) 36P connector Gauge Control Module Replacement.
24. Disconnect the ABS modulator-control unit 25P connector Service and Repair.
25. Disconnect SRS unit connector A (28P) SRS Unit Replacement.
26. With TPMS: Disconnect the TPMS control unit 20P connector Service and Repair.
27. Check for continuity between PCM connector terminal A36 and body ground.
Is there continuity?
YES -
Repair short in the wire between PCM connector terminal A36 and the gauge control module (tach), the ABS modulator-control unit, the SRS unit, the TPMS control unit (with TPMS), or the DLC.�
NO -
Go to step 28.
28. Check for continuity between PCM connector terminal A37 and body ground.
Is there continuity?
YES -
Repair short in the wire between PCM connector terminal A37 and the gauge control module (tach), the ABS modulator-control unit, the SRS unit, the TPMS control unit (with TPMS), or the DLC.�
NO -
Go to step 29.
29. Reconnect all connectors.
30. Connect the HDS to the DLC.
31. Disconnect the gauge control module (tach) 36P connector.
32. 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 -
Go to step 33.
33. Turn the ignition switch to LOCK (0).
34. Reconnect the gauge control module (tach) 36P connector.
35. Disconnect the ABS modulator-control unit 25P connector.
36. 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 37.
37. Turn the ignition switch to LOCK (0).
38. Reconnect the ABS modulator-control unit 25P connector.
39. Disconnect SRS unit connector A (28P).
40. 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 -
- With TPMS: Go to step 41.
- Without TPMS: Reconnect all connectors, then update the PCM if it does not have the latest software ECM/PCM Update, or substitute a known-good PCM, 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.�
41. Turn the ignition switch to LOCK (0).
42. Reconnect SRS unit connector A (28P).
43. Disconnect the TPMS control unit 20P connector.
44. 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 PCM if it does not have the latest software ECM/PCM Update, or substitute a known-good PCM, 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.�