Courtesy Lamp: Description and Operation

The Body Control Module (BCM) illuminates the courtesy lamps whenever a door is opened. When the last door is closed, the BCM "fades-to-OFF" the courtesy lamps in five seconds. If a door is left ajar, the courtesy lamps remain on for a maximum of one hour when ignition switch is OFF. After one hour, the BCM "fades-to-OFF" the courtesy lamps.