DTC Troubleshooting

DTC Troubleshooting: U1101

DTC U1101: F-CAN Malfunction (PCM-ACM)

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

1. Turn the ignition switch to ON (II).

2. Clear the DTC with the HDS.

3. Check for Temporary DTCs or DTCs with the HDS.

Is DTC U1101 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 engine mount control unit and the PCM.


4. Check for ACM system DTCs in the DTCs MENU with the HDS.

Is DTC P15AB indicated?
YES - Go to the ACM system's DTC P15AB troubleshooting. P15AB

NO - Go to step 5.


5. Turn the ignition switch to LOCK (0).

6. Jump the SCS line with the HDS.

7. Disconnect the engine mount control unit 16P connector.

8. Disconnect PCM connector A (49P).

9. Connect engine mount control unit 16P connector terminal No. 14 to body ground with a jumper wire.






10. Check for continuity between PCM connector terminal A48 and body ground.

Is there continuity?
YES - Go to step 11.

NO - Repair open in the wire between the PCM (A48) and the engine mount control unit, then go to step 13.






11. Connect engine mount control unit 16P connector terminal No. 12 to body ground with a jumper wire.






12. Check for continuity between PCM connector terminal A49 and body ground.

Is there continuity?
YES - Substitute a known-good engine mount control unit, Service and Repair then go to step 13 and recheck. If DTC U1101 is not indicated after substitution, replace the original engine mount control unit, Service and Repair then go to step 13.

NO - Repair open in the wire between the PCM (A49) and the engine mount control unit, then go to step 14.






13. Reconnect all connectors.

14. Turn the ignition switch to ON (II).

15. Reset the PCM with the HDS.

16. Do the PCM idle learn procedure. ECM/PCM Idle Learn Procedure

17. Check for Temporary DTCs or DTCs with the HDS.

Is DTC U1101 indicated?
YES - Check for poor connections or loose terminals at the engine mount control unit 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 DTC's troubleshooting.