Fog/Driving Lamp: Description and Operation

The fog lamp switch is a momentary switch that changes the fog lamp state from off to on or from on to off when pressed. The state of the fog lamps will remain the same until the fog lamp switch is pressed, even between ignition cycles. The fog lamps operate only when the ignition switch is in the ON or START position and the fog lamp state is on. The fog lamps will not illuminate when the high beam headlamps are on. When the fog lamps are on, the park lamps will also be activated. The fog lamp indicator will also illuminate. The underhood fuse block provides ignition 1 voltage to the Fog Lamp Relay coil through the IGN 1 fuse. The underhood fuse block also provides battery positive voltage to the Fog Lamp Relay switch through the FOG fuse. When the ignition switch is in the RUN OR START position, and the fog lamps switch is enabled, the instrument cluster fog lamps input is grounded through the headlamp switch to G205. In response to this input the IPC sends a class 2 message to the BCM in order to activate the fog lamps. The BCM provides ground to the Fog Lamp Relay coil.

The coil is then energized, closing the switch contacts. Battery positive voltage is then supplied to the fog lamps and the fog lamps ON indicator. The BCM also activates the park lamps when the fog lamps are on. When the fog lamps are enabled and the high beams or flash-to-pass are activated, the front fog lamps will be temporarily disabled for as long as the high beams or flash-to-pass are enabled. The park lamps will remain on during this period.