B1400

DTC B1400 (3-1): Communication Bus Line Error

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

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

Is DTC B 1400 (3-1) indicated?

YES - Go to step 4.

NO - Intermittent failure, the system is OK at this time. Check for loose or poor connections at the OnStar control unit connector A (22P), and at driver's under-dash fuse/relay box connector G(6P).

4. Check for DTCs with the HDS.

Is DTC B1000 also indicated?

YES - Troubleshoot DTC B1000.

NO - If only 3-1 is indicated, replace the OnStar control unit.