The interior lighting system includes the following components:

The body control module (BCM) regulates the illumination level of the instrument dial faces and the backlighting of the multifunction display (MFD) and LCDs. The illumination level is transmitted from the BCM via the secondary data bus and the receiving assemblies read the signal and adjust the illumination level accordingly. The BCM illumination drive controls the dash and center console illumination, the display window of the trip computer and the radio illumination. Two momentary contact switches in the headlamp switch ramp the illumination intensity up and down to adjust the level of brightness. The dimmer drives to 100 percent when the ignition is ON and the park lamps are OFF. This enables maximum brightness for the trip computer, HVAC and radio illumination. When the park lamps are switched ON, the dimmer operates according to the previously set percentage value. This intensity value is based on the priority key used. The dimmer control inputs are resistor encoded onto one input line. A 'bright' input occurs when DIM+ is activated and there is a 0 ohm reference to the park lamp control output. A 'dull' output occurs when DIM- is activated and there is a 2,700 ohm reference to the park lamp control output. The resting point of this line is 5,400 ohms. The system default is 100 percent when the circuit for this line is open. The default dimmer is 100 percent, which occurs if the battery or BCM is disconnected.

The cigar lighter illumination lamp lights whenever the parking lamps or headlamps are activated. The cigar lighter illumination lamp bulb socket is attached to the cigar lighter.

The dome lamp is located in the center of the headliner. The dome lamp consists of a clear lens, the dome lamp bulb and a three position slide switch. The slide switch has the following three detent positions:

Power comes from the Interior illumination fuse, through the interior illumination relay and finally provides voltage to the dome lamp, courtesy lamps, visor lamps and the ignition cylinder lamp. When the switch is in the OFF position, the dome lamp will not light. When the dome lamp switch is in the DOOR position, the lamp will light when any door is open. The lamp will remain on until all of the doors are closed. When the dome lamp switch is placed in the ON position, it provides a path to ground to the dome lamp and the lamp will illuminate.

Keyless Entry Interior Illumination

When operating the remote coded key, an radio frequency (RF) signal is transmitted to the remote key receiver. This receiver transfers the received data to the body control module (BCM). The BCM responds to the received signal based on the frequency of the RF signal, the button on the key that is pressed. When the doors are unlocked the BCM sends a ground to the interior illumination relay causing the interior lamps to turn ON.