DTC Troubleshooting

Control System DTCs

DTC Troubleshooting: U0155

DTC U0155 : F-CAN Malfunction (PCM-Gauge Control Module)

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information How to Troubleshoot the Fuel And Emissions Systems.


1. Problem verification:

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

-2. Clear the DTC with the HDS. How to Troubleshoot the Fuel And Emissions Systems

-3. Check for Pending or Confirmed DTCs with the HDS.

Is DTC U0155 indicated?
-YES- The failure is duplicated. Go to step 2.
-NO- Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the gauge control module and the PCM.

2. Gauge control module DTC check:

-1. Check for gauge control module DTCs with the HDS.

Is DTC U0029 and/or U0100 indicated?
-YES- Go to step 3.
-NO- Do the gauge control module input test.

3. Open wire check (F CAN-H line):

-1. Turn the ignition switch to LOCK (0).

-2. Jump the SCS line with the HDS.

-3. Disconnect the following connectors.






-4. Check for continuity between test points 1 and 2.










Is there continuity?
-YES- The F CAN-H wire is OK. Go to step 4.
-NO- Repair an open in the F CAN-H wire between the PCM (A3) and the gauge control module, then do the repair verification.

4. Open wire check (F CAN-L line):

-1. Check for continuity between test points 1 and 2.










Is there continuity?
-YES- The F CAN-L wire is OK. Substitute a known-good gauge control module Service and Repair, then do the repair verification. If DTC U0155 is not indicated after substitution, replace the original gauge control module Service and Repair, then do the repair verification.
-NO- Repair an open in the F CAN-L wire between the PCM (A4) and the gauge control module, then do the repair verification.

Repair verification:

-1. Turn the ignition switch to LOCK (0).

-2. Reconnect all connectors.

-3. Turn the ignition switch to ON (II).

-4. Reset the PCM with the HDS How to Troubleshoot the Fuel And Emissions Systems.

-5. Do the PCM idle learn procedure PCM Idle Learn Procedure.

-6. Check for Pending or Confirmed DTCs with the HDS.

Is DTC U0155 indicated?
-YES- Check for poor connections or loose terminals at the gauge control module and the 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.