Fog Lamps

WARNING: This page is about a different car, the 2008 Buick LaCrosse and 2008 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.

The FOG LAMPS fuse in the underhood fuse block supplies battery positive voltage to the coil and switch side FOG LAMP relay in the underhood fuse block. When the fog lamp switch is placed in the ON position, ground is applied from G202 through the fog lamp switch to the body control module (BCM). The BCM then applies a ground to the FOG LAMP relay control circuit. This energizes the FOG LAMP relay, and applies battery positive voltage to the fog lamp voltage supply circuit. Ground is applied to the left fog lamp from G101 and to the right fog lamp from G100. The park lamps or low beam headlights must be ON in order for the fog lamps to illuminate. In addition, the BCM will send the serial data class 2 message to illuminate the fog lamp indicator in the IPC. Fog lamp operation will be cancelled whenever the park lamps are turned OFF or the high beam headlamps are turned ON.