Body Control System Description and Operation: Notes

WARNING: This page is about a different car, the 2006 Chevrolet Monte Carlo and 2006 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.

The body control system consists of the body control module (BCM), communications, and various input and outputs, some outputs and messages requesting other modules to interact with the BCM. Battery positive voltage is provided to the BCM from the BCM fuse in the underhood fuse block. The module has two grounds at G202. The BCM is wired to the GMLAN High speed serial data buss and the GMLAN Low speed serial data buss and acts as a gateway between them. The BCM also has discrete input and output terminals to control the vehicle's body functions. If the BCM does not communicate the vehicle will not start due to the inability of the Engine/Powertrain Control Module (ECM/PCM) and Vehicle Theft Deterrent (VTD) Control Module to communicate without the BCM providing the gateway function.