F-CAN Circuit Troubleshooting - Part 1
F-CAN Circuit Troubleshooting (Part 1)NOTE: Information marked with an asterisk (*) applies to the CANL line.
1. Turn the ignition switch OFF.
2. Jump the SCS line with the HDS.
3. Disconnect PCM connector A (44P), then disconnect the HDS.
4. Measure resistance between PCM connector terminals A36 and A37*.
Is there about 85 - 105 ohms, on vehicles without TPMS, or about 82 - 100 ohms on vehicles with TPMS?
YES - Go to F-CAN circuit troubleshooting (Part 2).
NO - Go to step 5.
5. Disconnect the gauge control module (tach) 36P connector.
6. Disconnect the ABS modulator-control unit 25P connector.
7. Disconnect the servo unit 25P connector.
8. Disconnect EPS control unit connector D (28P).
9. Disconnect SRS unit connector A (28P).
10. On vehicles with TPMS, disconnect the TPMS control unit 20P connector.
11. Remove the rear seat.
12. Turn the battery module switch OFF.
13. Remove the IPU lid.
14. Remove the BCM module.
15. Disconnect the MCM 20P connector.
16. Check for continuity between PCM connector terminals A36 and A37*.
Is there continuity?
YES - Repair short in the wire between PCM terminals A36 and A37.
NO - Go to step 17.
17. Connect PCM connector terminal A36 to body ground with a jumper wire.
18. Check for continuity between gauge control module (tach) 36P connector terminal No. 1 and body ground.
Is there continuity?
YES - Go to step 19.
NO - Repair open in the wire between the PCM (A36) and the gauge control module (tach).
19. Check for continuity between ABS modulator-control unit 25P connector terminal No. 1 and body ground.
Is there continuity?
YES - Go to step 20.
NO - Repair open in the wire between the PCM (A36) and the ABS modulator-control unit.
20. Check for continuity between servo unit 25P connector terminal No. 1 and body ground.
Is there continuity?
YES - Go to step 21.
NO - Repair open in the wire between the PCM (A36) and the servo unit.
21. Check for continuity between EPS control unit connector D (28P) terminal No. 1 and body ground.
Is there continuity?
YES - Go to step 22.
NO - Repair open in the wire between the PCM (A36) and the EPS control unit.
22. Check for continuity between SRS unit connector A (28P) terminal No. 11 and body ground.
Is there continuity?
YES - Go to step 23.
NO - Repair open in the wire between the PCM (A36) and the SRS unit.
23. Check for continuity between BCM module connector terminal A1 and body ground.
Is there continuity?
YES - Go to step 24.
NO - Repair open in the wire between the PCM (A36) and the BCM module.
24. Check for continuity between MCM 20P connector terminal No. 20 and body ground.
Is there continuity?
YES -
- On vehicles with TPMS, go to step 25.
- On vehicles without TPMS, go to step 26.
NO - Repair open in the wire between the PCM (A36) and the MCM
25. Check for continuity between TPMS control unit 20P connector terminal No. 2 and body ground.
Is there continuity?
YES - Go to step 26.
NO - Repair open in the wire between the PCM (A36) and the TPMS unit.
26. Remove the jumper wire from PCM connector A (44P).
27. Connect PCM connector terminal A37 to body ground with a jumper wire.
28. Check for continuity between gauge control module (tach) 36P connector terminal No. 19 and body ground.
Is there continuity?
YES - Go to step 29.
NO - Repair open in the wire between the PCM (A37) and the gauge control module (tach)
29. Check for continuity between ABS modulator-control unit 25P connector terminal No. 17 and body ground.
Is there continuity?
YES - Go to step 30.
NO - Repair open in the wire between the PCM (A37) and the ABS modulator-control unit.
30. Check for continuity between servo unit 25P connector terminal No. 17 and body ground.
Is there continuity?
YES - Go to step 31.
NO - Repair open in the wire between the PCM (A37) and the servo unit.
31. Check for continuity between EPS control unit connector D (28P) terminal No. 15 and body ground.
Is there continuity?
YES - Go to step 32.
NO - Repair open in the wire between the PCM (A37) and the EPS control unit.
32. Check for continuity between SRS unit connector A (28P) terminal No. 12 and body ground.
Is there continuity?
YES - Go to step 33.
NO - Repair open in the wire between the PCM (A37) and the SRS unit.
33. Check for continuity between BCM module connector terminal A21 and body ground.
Is there continuity?
YES - Go to step 34.
NO - Repair open in the wire between the PCM (A37) and the BCM module.
34. Check for continuity between MCM 20P connector terminal No. 10 and body ground.
Is there continuity?
YES -
- On vehicles with TPMS, go to step 35.
- On vehicles without TPMS, go to step 36.
NO - Repair open in the wire between the PCM (A37) and the MCM
35. Check for continuity between TPMS control unit 20P connector terminal No. 11 and body ground.
Is there continuity?
YES - Go to step 36.
NO - Repair open in the wire between the PCM (A37) and the TPMS unit.
36. Remove the jumper wire from PCM connector A (44P).
37. Reconnect the gauge control module (tach) 36P connector.
38. Measure resistance between PCM connector terminals A36 and A37.
Is there about 2.34 - 2.86 kohms?
YES - Go to step 39.
NO - Substitute a known-good gauge control module (tach). If the HDS identifies the vehicle, replace the original gauge control module (tach).
39. Disconnect the gauge control module (tach) 36P connector.
40. Reconnect the ABS modulator-control unit 25P connector.
41. Measure resistance between PCM connector terminals A36 and A37.
Is there about 2.34 - 2.86 kohms?
YES - Go to step 42.
NO - Substitute a known-good ABS modulator-control unit. If the HDS identifies the vehicle, replace the original ABS modulator-control unit.
42. Disconnect the ABS modulator-control unit 25P connector.
43. Reconnect the servo unit 25P connector.
44. Measure resistance between PCM connector terminals A36 and A37.
Is there about 2.34 - 2.86 kohms?
YES - Go to step 45.
NO - Substitute a known-good servo unit. If the HDS identifies the vehicle, replace the original servo unit.
45. Disconnect the servo unit 25P connector.
46. Reconnect EPS control unit connector D (28P).
47. Measure resistance between PCM connector terminals A36 and A37*.
Is there about 2.34 - 2.86 kohms?
YES - Go to step 48.
NO - Substitute a known-good EPS control unit. If the HDS identifies the vehicle, replace the original EPS control unit.
48. Disconnect EPS control unit connector D (28P).
49. Reconnect SRS unit connector A (28P).
50. Measure resistance between PCM connector terminals A36 and A37*.
Is there about 2.34 - 2.86 kohms?
YES - Go to step 51.
NO - Substitute a known-good SRS unit. If the HDS identifies the vehicle, replace the original SRS unit.
51. Disconnect SRS unit connector A (28P).
52. Reconnect BCM module connector A (40P).
53. Measure resistance between PCM connector terminals A36 and A37*.
Is there about 108 - 132 ohms?
YES - Go to step 54.
NO - Substitute a known-good BCM module. If the HDS identifies the vehicle, replace the original BCM module.
54. Disconnect BCM module connector A (40P).
55. Reconnect the MCM 20P connector.
56. Measure resistance between PCM connector terminals A36 and A37*.
Is there about 2.34 - 2.86 kohms?
YES -
- On vehicles with TPMS, go to step 57.
- On vehicles without TPMS, update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM.
NO - Substitute a known-good MCM. If the HDS identifies the vehicle, replace the original MCM.
57. Disconnect the MCM 20P connector.
58. Reconnect the TPMS control unit 20P connector.
59. Measure resistance between PCM connector terminals A36 and A37*.
Is there about 2.34 - 2.86 kohms?
YES - Update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM.
NO - Substitute a known-good TPMS control unit. If the HDS identifies the vehicle, replace the original TPMS control unit.