Fuel and Emissions

DTC U0037: IMA-CAN Malfunction (BUS-OFF)

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.

1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Check for Temporary DTCs or DTCs with the HDS.

Is DTC U0037 indicated?

YES - Go to step 4.

NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the MCM, the BCM module, the A/C compressor driver, and the PCM.

4. Check for DTCs in the IMA system with the HDS.

Is DTC U0037 indicated?

YES - Go to step 5.

NO - Go to step 16.

5. Turn the ignition switch OFF.
6. Jump the SCS line with the HDS.
7. Disconnect PCM connector A (44P).
8. Remove the rear seat.
9. Turn the battery module switch OFF.
10. Remove the IPU lid.
11. Disconnect BCM module connector A (40P).
12. Connect PCM connector terminal A38 to body ground with a jumper wire.






13. Check for continuity between BCM module connector terminal A20 to body ground.






Is there continuity?

YES - Go to step 14.

NO - Repair open in the wire between the PCM (A38) and the BCM module (A20), then go to step 41.

14. Connect PCM connector terminal A39 to body ground with a jumper wire.






15. Check for continuity between BCM module connector terminal A40 to body ground.






Is there continuity?

YES - Go to step 47.

NO - Repair open in the wire between the PCM (A39) and the BCM module (A40), then go to step 41.

16. Turn the ignition switch OFF.
17. Remove the rear seat.
18. Turn the battery module switch OFF.
19. Remove the IPU lid.
20. Measure resistance between BCM module connector terminals A20 and A40 with connector connected.






Is there about 50.4 - 61.6 ohms?

YES - Go to step 22.

NO - Go to step 21.

21. Check the value of the resistance again.

Is there about 1 ohm or less?

YES - Repair short in the wires between the PCM (A38: IMACANH line) and (A39: IMACANL line), then go to step 41.

NO - Go to step 29.

22. Jump the SCS line with the HDS.
23. Disconnect PCM connector A (44P).
24. Remove the BCM module.
25. Disconnect the MCM 20P connector.
26. Disconnect the A/C compressor driver 4P connector.
27. Check for continuity between BCM module connector terminal A20 to body ground.






Is there continuity?

YES - Repair short in the wire between the PCM (A38) and the BCM module (A20), then go to step 41.

NO - Go to step 28.

28. Check for continuity between BCM module connector terminal A40 and body ground.






Is there continuity?

YES - Repair short in the wire between the PCM (A39) and the BCM module (A40), then go to step 41.

NO - Go to step 47.

29. Jump the SCS line with the HDS.
30. Disconnect PCM connector A (44P).
31. Disconnect the BCM module connectors (A), then remove the BCM module (B).






32. Disconnect the MCM 20P connector (C).
33. Disconnect the A/C compressor driver 4P connector.
34. Connect the BCM module connector A (40P), then measure resistance between BCM module connector terminals A20 and A40 with connector connected.






Is there about 108 - 132 ohms?

YES - Go to step 35.

NO - Substitute a known-good BCM module, then go to step 41 and recheck. If DTC U0037 is not indicated, replace the original BCM module, then go to step 41.

35. Disconnect BCM module connector A (40P).
36. Reconnect the MCM 20P connector.
37. Measure resistance between BCM module connector terminals A20 and A40.






Is there about 2.34 - 2.86 kohms?

YES - Go to step 38.

NO - Substitute a known-good the MCM, then go to step 41 and recheck. If DTC U0037 is not indicated, replace the original MCM, then go to step 41.

38. Disconnect the MCM 20P connector.
39. Reconnect the A/C compressor driver 4P connector.
40. Measure resistance between BCM module connector terminals A20 and A40.






Is there about 2.34 - 2.86 kohms?

YES - Go to step 47.

NO - Substitute a known-good the A/C compressor driver, then go to step 41 and recheck. If DTC U0037 is not indicated, replace the original A/C compressor driver, then go to step 41.

41. Reconnect all connectors.
42. Reinstall the IPU lid, then turn the battery module switch ON.
43. Turn the ignition switch ON (II).
44. Reset the PCM with the HDS.
45. Do the PCM idle learn procedure.
46. Check for Temporary DTCs or DTCs with the HDS.

Is DTC U0037 indicated?

YES - Check for poor connections or loose terminals at the MCM, the BCM module, the A/C compressor driver, and the PCM, then go to step 1.

NO - Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTCs troubleshooting.

47. Reconnect all connectors.
48. Reinstall the IPU lid, then turn the battery module switch ON.
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.

Is DTC U0037 indicated?

YES - Check for poor connections or loose terminals at the MCM, the BCM module, the A/C compressor driver, and the PCM. If the PCM was updated, substitute a known-good PCM, then recheck. If the PCM was substituted, go to step 1.

NO - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTCs troubleshooting.