Circuit Description
WARNING: This page is about a different car, the 2003 Pontiac Aztek and 2003 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.
The body control module (BCM) is the power mode master responsible for sending ignition switch position information on the class 2 serial data link. There are 3 discrete wires from the ignition switch contacts monitored by the BCM in order to determine the present power mode. The BCM communicates this power mode information to all class 2 modules on the class 2 serial data link. The following table represents BCM power mode data: