Circuit Description
WARNING: This page is about a different car, the 2006 Buick LaCrosse and 2006 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.
The body control module (BCM) controls the REAR WINDOW DEFOGGER relay circuit. When the ignition switch is in Run position and the operator has depressed the defogger switch, the BCM provides ground to the REAR WINDOW DEFOGGER relay control circuit and the electronic compass module. The electronic compass module translates the signal to compass data which is then transmitted to the instrument panel cluster (IPC) for display of the rear defogger mode.