U0037
DTC U0037: IMA-CAN Malfunction (Bus-Off) (MCM-PCM)NOTE:
- Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.
- Information marked with an asterisk (*) applies to the IMACANL line.
1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Check for Temporary DTCs or DTCs in the DTCs MENU with the HDS.
Is DTC U0037 indicated?
YES - Go to step 4.
NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the MCM, the A/C compressor driver and the PCM.
4. Turn the ignition switch OFF.
5. Measure resistance between PCM connector terminals D1* and D13.
Is there about 54-66 Ohm, at room temperature?
YES - Go to step 21.
NO - Go to step 6.
6. Jump the SCS line with the HDS.
7. Disconnect PCM connector D(17P).
8. Remove the IPU lid.
9. Disconnect MCM connector A (31P).
10. Disconnect the A/C compressor driver 4P connector.
11. Check for continuity between PCM connector terminals D1* and D13.
Is there continuity?
YES - Repair short in the wires between the PCM (D13 (IMACANH line)) and (D1 (IMACANL line)), then go to step 43.
NO - Go to step 12.
12. Connect between PCM connector terminal D1, D13 to body ground with a jumper wire individually.
13. Check for continuity between MCM connector terminals A6*,A7 and body ground individually.
Is there continuity?
YES - Go to step 14.
NO - Repair open in the wire between the MCM (A7 (A6)*) and the PCM (D13 (D1)*),then go to step 43.
14. Check for continuity between the A/C compressor driver 4P connector terminals No. 2, No. 3* and body ground individually.
Is there continuity?
YES - Go to step 15.
NO - Repair open in the wire between the A/C compressor driver (No. 2 (No. 3)*) and the PCM (D13 (D1)*), then go to step 43.
15. Remove the jumper wire from PCM connector D(17P).
16. Reconnect MCM connector A (31P).
17. Measure resistance between MCM connector terminals A6* and A7.
Is there about 108-132 Ohm, at room temperature?
YES - Go to step 18.
NO - Substitute a known-good MCM, then go to step 43 and recheck. If DTC U0037 is not indicated, replace the original MCM, then go to step 43.
18. Disconnect MCM connector A (31P).
19. Reconnect the A/C compressor driver 4P connector.
20. Measure resistance between A/C compressor driver 4P connector terminals No. 2 and No. 3*.
Is there about 2.3-2.9 k Ohm at room temperature?
YES - Go to step 49.
NO - Substitute a known-good A/C compressor driver , then go to step 43 and recheck. If DTC U0037 is not indicated, replace the original A/C compressor driver, then go to step 43.
21. Jump the SCS line with the HDS.
22. Disconnect PCM connector D (17P).
23. Remove the IPU lid.
24. Disconnect MCM connector A (31P).
25. Disconnect the A/C compressor control unit 4P connector.
26. Check for continuity between PCM connector terminal D1* and body ground, and between terminal D13 and body ground individually.
Is there continuity?
YES - Repair short in the wire between the MCM, the A/C compressor driver and the PCM (D13 (D1)*), then go to step 43.
NO - Go to step 27.
27. Disconnect PCM connector A (31P).
28. Check for continuity between PCM connector terminal A3 and body ground, and between terminal D16 and body ground individually.
Is there continuity?
YES - Go to step 29.
NO - Repair open in the wire between the PCM (A3, D16) and G101, then go to step 43.
29. Disconnect MCM connector B (24P).
30. Check for continuity between MCM connector terminal B3 and body ground, and between terminal B5 and body ground individually.
Is there continuity?
YES - Go to step 31.
NO - Repair open in the wire between the MCM (B3, B5) and G651, then go to step 43.
31. Check for continuity between A/C compressor driver 4P connector terminal No. 1 and body ground.
Is there continuity?
YES - Go to step 32.
NO - Repair open in the wire between the A/C compressor driver and G651, then go to step 43.
32. Reconnect PCM connectors A (31P) and D(17P).
33. Reconnect MCM connectors A (31P) and B (24P)
34. Turn the ignition switch ON (II).
35. Clear the DTC with the HDS.
36. Check for Temporary DTCs or DTCs with the HDS.
Is only DTC U0164 indicated?
YES - Substitute a known-good A/C compressor driver, then go to step 43 and recheck. If DTC U0037 is not indicated, replace the original A/C compressor driver, then go to step 43.
NO - Go to step 37.
37. Turn the ignition switch OFF.
38. Reconnect the A/C compressor driver 4P connector.
39. Disconnect MCM connector A (31P).
40. Turn the ignition switch ON (II).
41. Clear the DTC with the HDS.
42. Check for Temporary DTCs or DTCs with the HDS.
Is only DTC U0110 indicated?
YES - Substitute a known-good MCM, then go to step 43 and recheck. If DTC U0037 is not indicated, replace the original MCM, then go to step 43.
NO - Go to step 49.
43. Turn the ignition switch OFF.
44. Reconnect all connectors.
45. Turn the ignition switch ON (II).
46. Reset the PCM with the HDS.
47. Do the PCM idle learn procedure.
48. Check for Temporary DTCs or DTCs with the HDS.
Are any Temporary DTCs or DTCs indicated?
YES - If DTC U0037 is indicated, check for poor connections or loose terminals at the MCM, the A/C compressor driver and the PCM, then go to step 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.
NO - Troubleshooting is complete.
49. Update the PCM if it does not have the latest software, or substitute a known-good PCM.
50. Check for Temporary DTCs or DTCs with the HDS.
Are any Temporary DTCs or DTCs indicated?
YES - If DTC U0037 is indicated, check for poor connections or loose terminals at the MCM, the A/C compressor driver and the PCM, then go to step 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.
NO - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM.