Fuel and Emissions

DTC U1205: IMA-CAN Malfunction (PCM-MCM)

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 '06-07 models.

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

Are DTC U0037 and U1205 indicated at the same time?

YES - Go to troubleshooting for DTC U0037.

NO - Go to step 4.

4. Clear the DTC with the HDS.
5. Check for Temporary DTCs or DTCs with the HDS.

Is DTC U1205 indicated?

YES - Go to step 6.

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

6. Check for Temporary DTCs or DTCs with the HDS again.

Are DTC U0110 and U1205 indicated at the same time?

YES - Go to step 7.

NO - Go to step 15.

7. Turn the ignition switch OFF.
8. Remove the rear seat.
9. Turn the battery module switch OFF.
10. Remove the IPU lid.
11. Remove the BCM module.
12. Check for poor connections at the MCM 20P connector.

Are the connections OK?

YES - Go to step 12.

NO - Repair the poor connections at the MCM 20P connector, then go to step 32.

13. Reconnect BCM module connector A (40P), then turn the ignition switch ON (II), and measure voltage between MCM 20P connector terminal No. 18 and body ground within 1 second.

Is there battery voltage?

YES - Go to step 14.

NO - Go to step 23.

14. Check for continuity between body ground and MCM 20P connector terminals No. 2 and No. 9 individually.

Is there continuity?

YES - Go to step 22.

NO - Repair open in the wire between the BCM module (A20) and the MCM (No. 11), then go to step 32.

22. Check for continuity between BCM module connector terminal A40 and MCM 20P connector terminal No. 1.

Is there continuity?

YES - Update the MCM if it does not have the latest software, or substitute a known-good MCM, then go to step 32 and recheck. If DTC U1205 is not indicated with a known-good MCM, replace the original MCM, then go to step 32.

NO - Repair open in the wire between the BCM module (A40) and the MCM (No. 1), then go to step 32.

23. Turn the ignition switch OFF.
24. Remove MCM relay 2, and test it.

Is MCM relay 2 OK?

YES - Go to step 25.

NO - Replace MCM relay 2, then go to step 32.

25. Check the +B IMA2 (10 A) fuse in the auxiliary under-hood fuse/relay box.

Is the fuse OK?

YES - Go to step 26.

NO -
- Repair short in the wire between the +B IMA2 (10 A) fuse and MCM relay 2. Also replace the +B IMA2 (10 A) fuse, then go to step 32.
- Repair short in the wire between MCM relay 2 and the MCM, the IPU module fan. Also replace the +B IMA2 (10 A) fuse, then go to step 32.

26. Measure voltage between MCM relay 2 4P connector terminal No. 2 and body ground.

Is there battery voltage?

YES - Go to step 27.

NO - Repair open in the wire between the +B IMA2 (10 A) fuse and MCM relay 2, then go to step 32.

27. Check for continuity between MCM relay 2 4P connector terminal No. 1 and MCM 20P connector terminal No. 18.

Is there continuity?

YES - Go to step 28.

NO - Repair open in the wire between the MCM (No. 18) and MCM relay 2, then go to step 32.

28. Disconnect BCM module connector A (40P).
29. Check for continuity between MCM relay 2 4P connector terminal No. 3 and BCM module connector terminal A12.

Is there continuity?

YES - Go to step 30.

NO - Repair open in the wire between the BCM module (A12) and MCM relay 2, then go to step 32.

30. Remove MCM relay 1.
31. Check for continuity between MCM relay 1 4P connector terminal No. 1 and MCM relay 2 4P connector terminal No. 4.

Is there continuity?

YES - Update the BCM module if it does not have the latest software, or substitute a known-good BCM module, then go to step 32 and recheck. If DTC U1205 is not indicated with a known-good BCM module, replace the original BCM module, then go to step 32.

NO - Repair open in the wire between MCM relay 1 and MCM relay 2, then go to step 32.

32. Turn the ignition switch OFF.
33. Reconnect all connectors.
34. Reinstall the IPU lid, then turn the battery module switch ON.
35. Turn the ignition switch ON (II).
36. Reset the PCM with the HDS.
37. Do the PCM idle learn procedure.
38. Check for Temporary DTCs or DTCs with the HDS.

Is DTC U1205 indicated?

YES - Check for poor connections or loose terminals at the MCM, the BCM module, 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.