DTC Troubleshooting

DTC Troubleshooting: U0131

DTC U0131: F-CAN Malfunction (ECM-EPS)

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. Check for Temporary DTCs or DTCs with the HDS.

Are DTC U0028 and U0131 indicated at the same time?
YES - Go to troubleshooting DTC U0028.

NO - Go to step 3.


3. Clear the DTC with the HDS.

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

Is DTC U0131 indicated?
YES - Go to step 5.

NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the EPS control unit and the ECM.


5. Check for communication to the EPS system with the HDS.

Does the HDS communicate with the EPS control unit?
YES - Go to step 6.

NO - Go to the DLC circuit troubleshooting. Testing and Inspection


6. Turn the ignition switch OFF.

7. Jump the SCS line with the HDS.

8. Disconnect EPS control unit connector D (28P). Service and Repair

9. Disconnect ECM connector A (44P).

10. Connect ECM connector terminal A36 to body ground with a jumper wire.






11. Check for continuity between EPS control unit connector D (28P) terminal No. 1 and body ground.

Is there continuity?
YES - Go to step 12.

NO - Repair open in the wire between the ECM (A36) and the EPS control unit, then go to step 14.






12. Connect ECM connector terminal A37 to body ground with a jumper wire.






13. Check for continuity between EPS control unit connector D (28P) terminal No. 15 and body ground.

Is there continuity?
YES - Substitute a known-good EPS control unit, Service and Repair then go to step 14 and recheck. If no DTCs are indicated, replace the original EPS control unit, Service and Repair then go to step 14.

NO - Repair open in the wire between the ECM (A37) and the EPS control unit, then go to step 14.






14. Reconnect all connectors.

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

16. Reset the ECM with the HDS.

17. Do the ECM idle learn procedure. ECM Idle Learn Procedure

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

Is DTC U0131 indicated?
YES - Check for poor connections or loose terminals at the gauge control module (tach), the EPS control unit, and the ECM, 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.