B1401
DTC B1401 (1-1): OnStar Control Unit Internal Error (CPU Error)1. Delete the DTCs.
2. Turn the ignition switch OFF, and then back ON (II).
3. Check for DTCs.
Is DTC B1401 (1-1) indicated?
YES - Replace the OnStar control unit.
NO - Intermittent failure. The system is OK at this time. Check for loose or poor connections.