DTC B1000: Body Control Module Malfunction: Description
WARNING: This page is about a different car, the 2002 Pontiac Sunfire, 2002 Chevrolet Cavalier, 2001 Pontiac Sunfire, and 2001 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
Body Control Module (BCM) performs a self-test when ignition switch is turned to RUN position. An internal error has been sensed by BCM. No external circuits are involved.