Circuit/System Description
WARNING: This page is about a different car, the 2016 GMC Acadia, 2016 Chevrolet Traverse, and 2016 Buick Enclave. However, it is still accessible from the selected car via links, so may be relevant.
The body control module (BCM) controls the rear fog lamps based on inputs from the headlamp switch. When the rear fog lamp switch is pressed, a ground path is provided on the rear fog lamp switch signal circuit to the BCM, indicating the rear fog lamps ON command. In response to this signal, the BCM grounds the rear fog lamp relay control circuit energizing the Rear Fog Lamp Relay. With the rear fog lamp relay energized, battery voltage is applied through the RR FOG Fuse and the rear fog lamp control circuits illuminating the rear fog lamps.