Body Control Module (BCM)
WARNING: This page is about a different car, the 2006 Pontiac Montana SV6, 2006 Chevrolet Uplander, and 2006 Buick Terraza. However, it is still accessible from the selected car via links, so may be relevant.
The body control module (BCM) is a class 2 device. It communicates with the powertrain control module (PCM)/engine control module (ECM) and the instrument panel cluster (IPC) for electrical power management (EPM) operation. The BCM determines the output of the generator and sends the information to the PCM/ECM for control of the generator field control circuit. It monitors the generator field duty cycle signal circuit information sent from the PCM/ECM for control of the generator. It monitors a battery current sensor, the battery positive voltage circuit and estimated battery temperature to determine battery state-of-charge (SOC). The BCM performs idle boost and load management operations.