DTC Troubleshooting: U0131 (126)

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


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.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.n


NO - Go to 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 5.


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


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

Does the HDS communicate with the EPS control unit?


YES - Go to 6.


NO - Go to the DLC circuit troubleshooting.n


6.Turn the ignition switch OFF.

7.Jump the SCS line with the HDS.

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

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 12.


NO - Repair open in the wire between the ECM (A36) and the EPS control unit, then go to 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, then go to 14 and recheck. If DTC U0131 is not indicated, replace the original EPS control unit, then go to 14.


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

14.Reconnect all connectors and the battery.

15.Turn the ignition switch ON (II).

16.Reset the ECM with the HDS.

17.Do the ECM idle learn procedure.

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

Are any Temporary DTCs or DTCs indicated?


YES - If DTC U0131 is indicated, check for poor connections or loose terminals at the gauge control module (tach), the EPS control unit, and the ECM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.


NO - Troubleshooting is complete.n