Fog Lamps

FOG LAMPS
The BCM controls the operation of the fog lamp relay that turns the fog lamps ON and OFF. The Fog lamps can only be ON when the park and low beams are ON. If the high beams are switched ON, then the Fog lamps will be automatically turned OFF.

The Fog Lamp switch is a direct input to the BCM. The BCM sends a BUS message to the Front Control Module (FCM) informing it to turn on the fog lamp relay. The fog lamp relay is then powered through low side control of the FCM. This circuit is electronically controlled and continuously monitored for malfunctions. Fog lamp functionality is not equipped on all vehicles. The FCM "learns" that the vehicle is equipped with fog lamps by reading the BCM BUS message.