This group of interior lighting includes lamps which may be dimmed. This group uses a combination of class 2 controlled illumination and incandescent lamps:

The RH instrument panel (I/P) fuse block supplies battery positive voltage to both the coil and normally open switch contacts of the park lamp relay. When the body control module (BCM) energizes the park lamp relay, current flows from the park lamp relay switched contacts through the REAR PARK LP fuse to the I/P dimming switch. When dimming is selected, by moving the I/P dimming switch, all incandescent back lighting lamps, see schematics, and the BCM are provided with a variable voltage through the instrument panel lamp supply voltage #1 circuit. The incandescent back lighting lamps are then grounded at G201, G203 and G302. The BCM then applies a message signal to the class 2 circuit to the IPC and radio. The class 2 displays then dim to the level set by the I/P dimmer switch. When the I/P dimmer switch is moved from MIN to MAX, all class 2 displays and all incandescent back lighting respond from minimum intensity to maximum brightness.

Parade mode may be selected by manually turning on the park lamps during daylight conditions. The front park lamp circuit supplies voltage the HVAC assembly for a park lamp on input, and the display will become full bright. The BCM applies a message signal to the class 2 circuit to the IPC and radio commanding the displays to become full bright. The surveillance mode switch (SEO) overrides this feature.

The body control module (BCM) controls the lighting system through circuits that enable the park lamps, head lamps and fog lamps as well as the interior lamps. The BCM opens these enabling circuits 20 minutes after the ignition switch is turned OFF with no subsequent lamp switch activity. If the ignition switch is turned to any position other than OFF, or if a lamp switch is activated, during this 20-minute period, the timer will reset for another 20 minutes.