Courtesy Lamp: Description and Operation

EXTERIOR COURTESY LAMPS
The body control module (BCM), driver door module (DDM), and the passenger door module (PDM) communicate through the class 2 serial data system. The DDM and the PDM supply power and ground to the left and right exterior lamps respectively. When the BCM commands illuminated entry, a command is also sent to the DDM/PDM for illumination of the exterior courtesy lamps. If the door locks are activated to the LOCK position, or if the ignition switch is turned to either the ON or RUN position the exterior courtesy lamps will deactivate immediately.

When an outside door handle is lifted or a door is opened, the exterior courtesy lamps illuminate.

COURTESY/ILLUMINATED ENTRY LAMPS
The courtesy/illuminated entry lamps, may be manually turned on or off by placing the interior lamp switch in the ON or OFF position. If an outside door handle is lifted or a door is opened, the courtesy/illuminated entry lamps illuminate. After all the doors have been closed the courtesy/illuminated entry lamps will remain illuminated approximately 15 seconds. The courtesy/illuminated entry lamps will also turn on prior to any door being opened, and remain illuminated approximately 40 seconds when the driver removes the ignition key. When the driver places the dome lamp defeat switch in the OFF position, the courtesy/illuminated entry lamps will be disabled.

The left and right front door courtesy lamps are controlled, and receive voltage and ground from the drivers door module (DDM) and the passenger door module (PDM) respectively. The body control module (BCM), DDM, and the PDM communicate through class II serial data for the lamp illumination commands and the door ajar switches.

The remaining courtesy lamps are controlled and receive voltage from the BCM. Voltage for the courtesy lamp supply voltage circuit and the backup lamp supply voltage circuit is from the TBC B fuse in the instrument panel fuse block directly through the BCM to these circuits. A short to ground on either of these circuits will open the fuse. Ground is provided to the footwell lamps and all courtesy/reading lamps at G203. Ground is provided to the right middle and right rear door at G306. Ground is provided to the left middle and left rear door at G302.