Fog/Driving Lamp: Description and Operation

The fog lamps are located in the bumper fascia beneath the headlamp assemblies. The front fog lamp switch is located below the headlamp switch on the left side of the Instrument Panel Cluster (IPC). Pressing the fog lamp switch button will turn the fog lamps ON, as long as the headlamp switch is NOT in the OFF position. When the fog lamps are ON, an indicator on the fog lamp switch will illuminate. Pressing the switch again will turn the fog lamps OFF. The FOG LAMP relay in the fuse block - underhood controls the fog lamps. The switched side of the relay receives battery voltage at all times from the FOG LP Fuse. The coil side feed circuit of the fog lamp relay receives voltage from the HDLP fuses via an inactive high beam headlamp (the voltage will be pulled low with the high beams ON disabling the fog lamps). The BCM will provide an enable signal to the tog lamp switch when the ignition is ON and the headlamp switch is in PARK or HEAD position. With the tog lamp enable circuit active and the tog lamp switch is pressed, a ground is applied to the fog lamp relay control circuit. This energizes the relay, closing the switched contact and applying battery voltage to the fog lamps. The fog lamps receive a constant ground.