GM Service Manual Online
For 1990-2009 cars only

The body control system consists the body control module (BCM).

Battery voltage is provided from the IP fuse block to the BCM. Ignition voltage is provided from the IP fuse block to the BCM. The module ground is wired to ground. The BCM is wired to the Class 2 serial data line. The various BCM input and output circuits are described in the corresponding functional areas as indicated on the BCM electrical schematics.