Circuit/System Description
WARNING: This page is about a different car, the 2006 Chevrolet Monte Carlo and 2006 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.
The fog lamps are controlled by the body control module (BCM) by inputs from the for lamp switch. When the BCM receives a fog lamps ON signal, it grounds the fog lamp relay control circuit in order to energize the FOG LAMP PCB Relay. With the relay energized, battery voltage is applied through the switch side of the relay, the FOG LAMPS Fuse, and the fog lamps supply voltage circuits to the fog lamps.