Gauge Control Module Lost Communication With VSA Modulator-Control Unit (VSA message)

DTC Troubleshooting: U0122

DTC U0122:

Gauge Control Module Lost Communication With VSA Modulator-Control Unit (VSA message)

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. Wait for at least 6 seconds.

4. Check for DTCs with the HDS.

Is DTC U0122 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 and the VSA modulator-control unit with the HDS. If F-CAN DTCs are present, check for a loose VSA ground or poor connections at the VSA modulator-control unit or gauge control module. 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 or VSA with the HDS.

Are any DTCs indicated?

YES -

Go to the ECM/PCM or VSA indicated DTC's, troubleshooting.�

NO -

Go to step 6.

6. Do the gauge control module input test Component Tests and General Diagnostics.

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. Check for DTCs with the HDS.

Is DTC U0122 indicated?

YES -

Recheck ECM/PCM for DTCs, then recheck the VSA modulator-control unit for DTCs.�

NO -

The original gauge control module is faulty; replace it Gauge Control Module Replacement.�