DTC U0131: F-CAN Malfunction (ECM/PCM-EPS Control Unit)

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review GENERAL TROUBLESHOOTING INFORMATION .

Turn the ignition switch to ON (II).
Check for Pending or Confirmed DTCs with the HDS.
Are DTC U0029 and U0131 indicated at the same time?

YES: Go to the troubleshooting for DTC U0029 (see DTC U0029: F-CAN MALFUNCTION (BUS-OFF (ECM/PCM)) ).

NO: Go to step 3.
Clear the DTC with the HDS.
Check for Pending or Confirmed 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/PCM.
Start the engine, and watch the EPS indicator.
Does the indicator come on and go off?

YES: Go to step 6.

NO: Turn the ignition switch to LOCK (0), and go to symptom troubleshooting for EPS indicator does not go off, and no DTC stored (see SYMPTOM TROUBLESHOOTING ).
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect EPS control unit connector A (11P).
Disconnect ECM/PCM connector A (49P).
Check for continuity between ECM/PCM connector terminal A3 and body ground.
Is there continuity?

YES: Go to step 11.

NO: Repair open in the wire between the ECM/PCM (A3) and the EPS control unit, then go to step 12.

Fig 1: Checking Continuity Between ECM/PCM Connector Terminal A3 & Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between ECM/PCM connector terminal A4 and body ground.
Is there continuity?

YES: Substitute a known-good EPS control unit, then go to step 12 and recheck. If DTC U0131 is not indicated after substitution, replace the original EPS control unit, then go to step 12.

NO: Repair open in the wire between the ECM/PCM (A4) and the EPS control unit, then go to step 12.

Fig 2: Checking Continuity Between ECM/PCM Connector Terminal A4 & Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the ECM/PCM with the HDS.
Do ECM/PCM IDLE LEARN PROCEDURE .
Check for Pending or Confirmed DTCs with the HDS.
Is DTC U0131 indicated?

YES: Check for poor connections or loose terminals at the EPS control unit and the ECM/PCM, then go to step 1.

NO: Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.