Courtesy Lamp: Description and Operation

COURTESY/ILLUMINATED ENTRY LAMPS
Courtesy/illuminated entry lamps are lamps that may be illuminated by opening a door, manually operating a switch or through a remote control door lock receiver (RCDLR) command. This group consist of the following lamps:
- Door courtesy lamps
- Footwell lamps
- Illuminated entry lamps
- Instrument panel (I/P) compartment lamps
- Overhead console courtesy/reading lamps
- Rear compartment lamps
- Vanity mirror lamps

The rear integration module (RIM) controls battery positive voltage and ground to the interior courtesy lamps in the following manner. Battery positive voltage is supplied through the INTERIOR LAMP fuse to both the switch side and coil side of the interior lamp relay. The RIM provides a ground to the control circuit of the interior lamp relay during all power modes except when battery run down protection is active. With the interior lamp relay energized, battery positive voltage is supplied to all the interior lamps in this group. The ground side circuits of the door, footwell, and overhead courtesy lamps are controlled by a pulse width modulated (PWM) ground circuit of the RIM. The RIM pulses the on time of the ground circuit between 0-100 percent at a frequency of approximately 100 hertz. By decreasing the on time percentage of the controlled ground circuit the intensity of the lamps will decrease. This effect is called theater dimming. The RIM will illuminate these lamps under various conditions which will be described in the following information:

COURTESY/ILLUMINATED ENTRY
Courtesy/illuminated entry occurs when any of the door control modules receive a discrete input from the door open switch located in the door latch assembly. The appropriate door control module sends a GMLAN serial data message to the RIM indicating a door is opened. If the ambient light sensor status is dark, the RIM will illuminate the courtesy lamps. The lamps will remain illuminated for 25 seconds after all the doors are closed or until the ignition is placed in the ON position. At this time the RIM will fade the lamps from full intensity to OFF in 3-5 seconds by activating the theater dim feature.