Courtesy Lamp: Description and Operation

PRINCIPLES OF OPERATION

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

The interior lamps consist of the dome lamp and the cargo area lamp. The interior lamps can be activated by the smart junction box (SJB) using the panel dimmer switch, or by any door ajar switch. The interior 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 km/h (5 mph). The interior lamps will not be reactivated until the vehicle speed is less than 5 km/h (3 mph) and a new door open warning lamp switch signal is received.

The inputs are:
- ignition switch position
- LF door ajar switch
- RF door ajar switch
- LR door ajar switch
- RR door ajar switch

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

Illuminated Entry (option)
The illuminated entry feature requests the interior lamps be lit when the ignition switch is in the OFF position and the operator activates an external unlock feature (keyfob or transmitter, key pad, key cylinder). The illuminated entry feature requests the interior 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 remote keyless entry (RKE) module

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

Demand Lamps
The demand lamps are those lamps which have their own switch and can be operated independently. The demand lamps consist of:
- RH map lamp
- LH map lamp
- glove compartment lamp

The demand lamps are also controlled by the interior lighting arbitrator and the battery saver relay.

Interior Lighting Arbitrator
The interior lighting arbitrator decides between interior lighting, illuminated entry lighting, and battery saver features to determine which feature has precedence of turning on and off the interior lights. This feature is internal in the SJB. 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 interior lamps and the warning chimes. The battery saver has time-out periods of 10 minutes for the interior lamps if the dome switch is in the OFF position, 30 minutes for the interior lamps if the dome switch is in the ON position and 30 minutes for the demand lamps. The battery saver will restore power to the interior lamps or reset the 10/30 minute timer if 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 inputs are:
- ignition switch position
- key in ignition switch
- LF door ajar switch
- RF door ajar switch
- LR door ajar switch
- RR door ajar switch
- illuminated entry request from the remote keyless entry (RKE) module, keyfob, key cylinder lock/unlock

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