Battery positive voltage (B+) is applied at all times to the lamp control module (LCM) through the underhood junction block HDLP MaxiFuse® and CKT 1242 (RED).

When you place the headlamp switch in the HEAD position, the headlamps input to the LCM is grounded. The LCM then applies battery positive voltage (B+) through the underhood junction block HDLOBML fuse and HDLOBMR fuse, which feed the left low beam headlamp and the right low beam headlamp respectively. When you activate the headlamp dimmer switch by pulling on the multifunction lever until the switch clicks, CKT 524 (PPL) is grounded to the LCM. The LCM then removes battery positive voltage (B+) from the low beam headlamps and supplies battery positive voltage (B+) through the underhood junction block HDHIBML fuse and HDHIBMR fuse, which feed the left high beam headlamp and the right high beam headlamp respectively.

When the multifunction lever is pulled towards the driver but does not click, CKT 307 (YEL) is grounded to the LCM. The LCM then supplies battery positive voltage (B+) to the high beam headlamps until the multifunction lever is released. The flash-to-pass function will override the low beam headlamps or the daytime running lamps (DRL) if either system is active.

The lamp control module (LCM) monitors the ambient light conditions through the ambient light sensor. The ambient light sensor is a variable resistor. The resistance of the ambient light sensor changes according to the exterior ambient light level. The resistance of the ambient light sensor increases as the ambient light decreases. The LCM measures the voltage across the ambient light sensor.

Perimeter lighting provides a personal security feature. The perimeter lighting feature illuminates the exterior lights on the outside of the vehicle for 15 seconds when the keyless entry transmitter is used to unlock the doors under nighttime conditions. The following lamps illuminate when the perimeter lighting is activated:

When you press the UNLOCK button on the keyless entry transmitter, the remote function actuator (RFA) module grounds CKT 624 (BLK/WHT) to the lamp control module (LCM). The LCM then provides battery positive voltage (B+) to the headlamps and the park lamps. The RFA provides ground for the PERIM LP relay through CKT 1655 (DK GRN). The coil energizes and the switch contacts close providing battery positive voltage (B+) to the backup lamps.