F-CAN Circuit Troubleshooting
F-CAN Circuit TroubleshootingNOTE: 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 (49P), then disconnect the HDS.
4. Measure resistance between PCM connector terminals A48 and A49*.
Is there about 20 - 62 ohms?
YES - Go to step 38.
NO - Go to step 5.
5. Disconnect the gauge control module 30P connector.
6. Disconnect the VSA modulator-control unit 47P connector.
7. Disconnect SRS unit connector A (28P).
8. Disconnect TPMS control unit connector B (20P).
9. With VCM system: Disconnect engine mount control unit 20P connector.
10. 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 11.
11. Connect PCM connector terminal A48 to body ground with a jumper wire.
12. Check for continuity between gauge control module 30P connector terminal No. 24 and body ground.
Is there continuity?
YES - Go to step 13.
NO - Repair open in the wire between the PCM (A48) and the gauge control module.
13. Check for continuity between VSA modulator-control unit 47P connector terminal No. 11 and body ground.
Is there continuity?
YES - Go to step 14.
NO - Repair open in the wire between the PCM (A48) and the VSA modulator-control unit.
14. Check for continuity between SRS unit connector A (28P) terminal No. 11 and body ground.
Is there continuity?
YES - Go to step 15.
NO - Repair open in the wire between the PCM (A48) and the SRS unit.
15. Check for continuity between TPMS control unit connector B (20P) terminal No. 19 and body ground.
Is there continuity?
YES -
- With VCM system: Go to step 16.
- Without VCM system: Go to step 17.
NO - Repair open in the wire between the PCM (A48) and the TPMS control unit.
16. Check for continuity between engine mount control unit 20P connector terminal No. 5 and body ground.
Is there continuity?
YES - Go to step 17.
NO - Repair open in the wire between the PCM (A48) and the engine mount control unit.
17. Remove the jumper wire from PCM connector A (49P).
18. Connect PCM connector terminal A49 to body ground with a jumper wire.
19. Check for continuity between gauge control module 30P connector terminal No. 23 and body ground.
Is there continuity?
YES - Go to step 20.
NO - Repair open in the wire between the PCM (A49) and the gauge control module.
20. Check for continuity between VSA modulator-control unit 47P connector terminal No. 15 and body ground.
Is there continuity?
YES - Go to step 21.
NO - Repair open in the wire between the PCM (49P) and the VSA modulator-control unit.
21. Check for continuity between SRS unit connector A (28P) terminal No. 12 and body ground.
Is there continuity?
YES - Go to step 22.
NO - Repair open in the wire between the PCM (49P) and the SRS unit.
22. Check for continuity between TPMS control unit connector B (20P) terminal No. 10 and body ground.
Is there continuity?
YES -
- With VCM system: Go to step 23.
- Without VCM system: Go to step 24.
NO - Repair open in the wire between the PCM (A49) and the TPMS control unit.
23. Check for continuity between engine mount control unit 20P connector terminal No. 17 and body ground.
Is there continuity?
YES - Go to step 24.
NO - Repair open in the wire between the PCM (49P) and the engine mount control unit.
24. Reconnect the gauge control module 30P connector.
25. Measure resistance between PCM connector terminals A48 and A49*.
Is there about 2.34 - 2.86 KOhms?
YES - Go to step 26.
NO - Substitute a known-good gauge control module. If the HDS identifies the vehicle, replace the original gauge control module.
26. Disconnect the gauge control module 30P connector.
27. Reconnect the VSA modulator-control unit 47P connector.
28. Measure resistance between PCM connector terminals A48 and A49*.
Is there about 108 - 132 KOhms?
YES - Go to step 29.
NO - Substitute a known-good VSA modulator-control unit. If the HDS identifies the vehicle, replace the original VSA modulator-control unit.
29. Disconnect the VSA modulator-control unit 47P connector.
30. Reconnect SRS unit connector A (28P).
31. Measure resistance between PCM connector terminals A48 and A49*.
Is there about 2.34 - 2.86 KOhms?
YES - Go to step 32.
NO - Substitute a known-good SRS unit. If the HDS identifies the vehicle, replace the original SRS unit.
32. Disconnect SRS unit connector A (28P).
33. Reconnect TPMS control unit connector B (20P).
34. Measure resistance between PCM connector terminals A48 and A49*.
Is there about 108 - 132 ohms?
YES -
- With VCM system: Go to step 35.
- Without VCM system: 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.
35. Disconnect TPMS control unit connector B (20P).
36. Reconnect the engine mount control unit 20P connector.
37. Measure 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, 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 engine mount control unit. If the HDS identifies the vehicle, replace the original engine mount control unit.
38. Disconnect the gauge control module 30P connector.
39. Disconnect the VSA modulator-control unit 47P connector.
40. Disconnect SRS unit connector A (28P).
41. Disconnect TPMS control unit connector B (20P).
42. With VCM system: Disconnect the engine mount control unit 20P connector.
43. Check for continuity between PCM connector terminal A48 and body ground.
Is there continuity?
YES - Repair short in the wire between PCM connector terminal A48 and the gauge control module, the VSA modulator-control unit, the SRS unit, the TPMS control unit, the engine mount control unit (with VCM system), or the DLC.
NO - Go to step 44.
44. Check for continuity between PCM connector terminal A49 and body ground.
Is there continuity?
YES - Repair short in the wire between PCM connector terminal A49 and the gauge control module, the VSA modulator-control unit, the SRS unit, the TPMS control unit, the engine mount control unit (with VCM system), or the DLC.
NO - Go to step 45.
45. Reconnect all connectors.
46. Connect the HDS to the DLC.
47. Disconnect the gauge control module 30P connector.
48. Turn the ignition switch ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES - Replace the gauge control module.
NO - Go to step 49.
49. Turn the ignition switch OFF.
50. Reconnect the gauge control module 30P connector.
51. Disconnect the VSA modulator-control unit 47P connector.
52. Turn the ignition switch ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES - Replace the VSA control unit.
NO - Go to step 53.
53. Turn the ignition switch OFF.
54. Reconnect the VSA modulator-control unit 47P connector.
55. Disconnect SRS unit connector A (28P).
56. Turn the ignition switch ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES - Replace the SRS unit.
NO - Go to step 57.
57. Turn the ignition switch OFF.
58. Reconnect SRS unit connector A (28P).
59. Disconnect TPMS control unit connector B (20P).
60. Turn the ignition switch ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES - Replace the TPMS control unit.
NO -
- With VCM system: Go to step 61.
- Without VCM system: 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.
61. Turn the ignition switch OFF.
62. Reconnect TPMS control unit connector B (20P).
63. Disconnect the engine mount control unit 20P connector.
64. Turn the ignition switch ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES - Replace the engine mount control unit.
NO - 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.