Dome Lamp
WARNING: This page is about a different car, the 2009 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
The dome lamp is turned ON by the lamp switch assembly or during illuminated entry.
During illuminated entry or when the lamp switch assembly is in the DOME position, the body control module (BCM) wakes up and then energizes the courtesy lamps supply voltage circuit, suppling voltage to all interior lamps.