Operation CHARM: Car repair manuals for everyone.

Roof Rail Courtesy Lamps

The root rail courtesy lamps are turned ON by the interior lamp switch, the individual roof rail courtesy lamp switch, or during illuminated entry.

During illuminated entry or when the interior lamps switch is ON the BCM wakes up and then energizes the courtesy lamps supply voltage circuit, suppling voltage to all interior lamps. The BCM pulls the courtesy lamp low control circuit low, providing ground to the roof rail courtesy lamps and all courtesy lamps.

The root rail courtesy lamps can be turned on from the individual roof rail courtesy lamp switch. The BCM supplies voltage through the courtesy lamps supply voltage circuit when the BCM is awake. Manually turning on the roof rail courtesy lamp switch provides a ground path.