B1408

DTC B1408 (3-5): OnStar Control Unit Lost Communication with Gauge Control Module (VSP/NE Message)

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

1. Delete the DTCs.
2. Turn the ignition switch OFF, and then back ON (II).
3. Check for DTCs).

Is DTC B1408 (3-5) indicated?

YES - Go to step 4.

NO - Intermittent failure. The system is OK at this time. Check for loose or poor connections.

4. Check for DTCs with the HDS.

Are DTCs B1011, B1060, B1205, B1610, B1805 and B2160 also indicated?

YES - Go to the gauge control module input test. Gauge Control Module Input Test If the gauge control module input test is OK, replace the OnStar control unit.

NO - Replace the OnStar control unit.