Courtesy Lamp: Description and Operation

Interior Lighting
The interior lighting is broken down into two groups: the courtesy lamps and the illuminated entry lamps. Both lighting features interact with the courtesy light arbitrator. The battery saver is also listed.

Courtesy Lighting
The courtesy lamps consist of the dome lamp and/or map lights. The courtesy lamps can be activated by the Generic Electronic Module (GEM) using the panel dimmer switch, or by any ajar door. The courtesy lamps will shut off when the doors are closed and the illuminated entry feature is not active, or when the vehicle speed is greater than 8 kph (5 mph). The interior lamps will not be reactivated until the vehicle speed is less than 5 kph (3 mph) and a new door open warning lamp switch signal is received.

The inputs are:
^ ignition switch position
^ driver door ajar switch
^ front passenger door ajar switch
^ rear left door ajar switch
^ rear right door ajar switch
^ Vehicle Speed Switch (VSS)

The outputs are:
^ battery saver relay
^ interior lamp relay

Illuminated Entry (option)
The illuminated entry feature requests the courtesy lamps be lit when the ignition switch is turned OFF and the customer activates an external unlock feature (keyfob or transmitter, key pad, key cylinder). The illuminated entry feature requests the courtesy lamps to extinguish when: 25 seconds expire, the ignition transitions out of OFF, or the customer activates an external lock feature. If a door becomes ajar before the 25 second timer expires, the timer will be reset. A second door ajar event will have no effect on the timer.

The inputs are:
^ ignition switch position
^ illuminated entry request (from the automatic transmission module)

The outputs are:
^ battery saver relay
^ interior lamp relay

Courtesy Lighting Arbitrator
The courtesy lighting arbitrator arbitrates between courtesy lighting, illuminated entry lighting, and battery saver features to determine which feature has precedence of turning on and off the courtesy lights. This feature is internal in the GEM.

The outputs are:
^ battery saver relay
^ interior lamp relay

Battery Saver
When ignition is OFF or the key is out, the battery saver timer feature provides timed automatic shut-off of power to the courtesy lamps, the demand lamps and the warning chimes. The battery saver has a time-out period of 10 minutes. If the battery saver has the power to the courtesy lamps, the demand lamps and the warning chimes turned off, it will restore power to the courtesy lamps, the demand lamps and the warning chimes when any of the following interactions is detected:
^ the ignition key is put in the ignition
^ the ignition is turned in any position other than OFF
^ any door becomes ajar
^ any button of a remote or exterior device which provides access to the vehicle is pressed (keyfob, keypad).

The battery saver will also reset the 10 minute timer if any of the above interactions occur.

The inputs are:
^ ignition switch position
^ key in ignition switch
^ driver door ajar switch
^ front passenger door ajar switch
^ rear left door ajar switch
^ rear right door ajar switch
^ illuminated entry request (from the automatic transmission module, keyfob valid Transponder Identification Code [(TIC)], key cylinder lock/unlock)

The outputs are:
^ interior lamp relay
^ battery saver relay
^ warning chimes (internal to the GEM)