Demand Lamps
WARNING: This page is about a different car, the 2014 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.
The demand lamps subsystem consists of the map/reading lamps and the vanity mirror lamps located in the visors. The BCM energizes the battery saver relay to supply voltage to the demand lamps when the battery saver feature is not active.