Gauge Control Module

DTC Troubleshooting: U0100 (Gauge Control Module)

DTC U0100: Gauge Control Module Lost Communication with ECM/PCM

NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A. Troubleshooting - B-CAN System Diagnosis Test Mode A

1. Clear the DTCs with the HDS.

2. Turn the ignition switch to LOCK (0) and then back to ON (II).

3. Start and run the engine for at least 5 seconds, then turn the engine off.

4. Check for DTCs with the HDS.

Is DTC U0100 indicated?
YES - Go to step 5.

NO - Intermittent failure, the F-CAN communication line is OK at this time. Check for DTCs in the ECM/PCM with the HDS. If F-CAN DTCs are present, check for loose or poor connections at the gauge control module and the ECM/PCM. If the connections are good, check the battery condition and the charging system, then clear all DTCs.


5. Check for DTCs in the ECM/PCM with the HDS.

Are any DTCs indicated?
YES - Go to the ECM/PCM indicated DTC's troubleshooting.

NO - Go to step 6.


6. Do the gauge control module input test.

Are all inputs OK?
YES - Go to step 7.

NO - Repair the faulty input, then recheck the DTCs.


7. Substitute a known-good gauge control module.

8. Clear the DTCs with the HDS.

9. Turn the ignition switch to LOCK (0) and then back to ON (II).

10. Start and run the engine for at least 5 seconds, then turn the engine off.

11. Check for DTCs with the HDS.

Is DTC U0100 indicated?
YES - Replace the ECM/PCM.

NO - The original gauge control module is faulty; replace it.