The exterior lighting system consist of the following lamps:

The headlamps may be turned on in two different ways. First, when the driver places the headlamp switch in the HEADLAMP position, for normal operation. Second, with the headlamp switch placed in the AUTO position, for automatic lamp control (ALC). During ALC control the headlamps will be in day time running lamp (DRL) operation in daylight conditions, or low beam operation in low light conditions.

Battery positive voltage to the headlamp switch is supplied by the TBC fuse in the IP fuse block. When the headlamp switch is in the HDLP position, the headlamp power relay coil is energized. A voltage signal is also sent to the body control module (BCM) signaling that the headlamp switch is activated. Battery positive voltage is supplied to the headlamp power relay by the LIGHTING fuse in the underhood fuse block. The headlamp power relay coil is grounded at G101. When the headlamp power relay is energized, the relay supplies battery voltage to the HEADLAMP Fuse LH and HEADLAMP Fuse RH in the underhood fuse block. Both low and high beam headlamps are grounded by the multifunction headlamp dimmer switch in the their respective position through the normally closed DRL relay in the body relay block to G110.

The export vehicle headlamps function the same way as the domestic except the DRL relay is deleted out of the circuit.

The ambient light sensor is a light sensitive transistor that varies its voltage signal to the body control module (BCM) in response to changes to the outside (ambient) light level. When the BCM receives this signal it will either turn on the daytime running lamps (DRL) or the headlights for auto headlamp operation. Any function or condition that turns on the headlights will cancel the daytime running lamps operation. With the headlight switch in the OFF position, the headlights will either be turned ON or OFF, after an approximate 8 second delay depending on whether daylight or low light conditions are sensed. The DRL will operate when the ignition switch is in the RUN position, the gear selector is not in the PARK position and the parking brake is released. When these conditions have been met and the ambient light sensor indicates daytime conditions, the DRL will illuminate.

The DRL relay is supplied battery positive voltage by the GAUGES fuse in the IP fuse block. When the BCM requests DRL operation, the DRL relay coil is grounded by the BCM activating the relay. The energized DRL relay bypasses the multifunction headlamp dimmer switch by rerouting ground G110 directly to both low beam headlamp bulbs.

The automatic lamp control (ALC) system and the daytime running lamps (DRL) feature (except the Canadian version) can be temporarily disabled by performing the following procedure:

1. Turn the ignition to RUN.
2. Press the DOME OVERRIDE button four times within six seconds.

A chime will sound informing you that the system is off. The system will remain disabled until the ignition is cycled off and then on or by pressing the DOME OVERRIDE button four more times within six seconds. The chime will sound again signaling that the system has been reactivated.

The export vehicle is not equipped with the DRL feature.

The park, tail, marker and license lamps are turned on when the headlamp switch is placed in the PARK or ON position or anytime the headlights are requested. The PK LPS fuse in the IP fuse block supplies battery positive voltage to the park lamp relay and the headlamp switch. The body control module (BCM) provides a ground, or control circuit, to the park lamp relay coil circuit during ALC operation. When the park lamps are turned on during ALC, the BCM energizes the park lamp relay. The park lamps can also be supplied battery positive voltage directly from the headlamp switch. Current flow is to the park, tail, marker and license lamps. The front park and marker lamps are grounded at G100 and G101. The rear park, tail, marker and license lamps are grounded at G400 and G401. If the headlight switch is left in the ON position, the park, tail and marker lamps will remain on until turned off or the battery runs dead.

The STOP/HAZ fuse in the IP fuse block supplies battery positive voltage to the multifunction hazard switch assembly. The TURN-B/U fuse in the IP fuse block supplies Ignition positive voltage to the multifunction turn signal switch assembly. With the ignition switch in the RUN or START position, ignition positive voltage is connected through the multifunction turn signal and hazard switch assembly to the flasher module which is grounded at G105. When the turn signal switch is placed in either the left or right position, the circuit is complete from the flasher module to the turn signal lamps and to ground. The flasher module then sends an on-off voltage signal to either the left or right turn signals and their instrument panel cluster (IPC) indicator. When the hazard switch is activated, all turn signal lamps will flash including both IPC turn indicators. The front turn signals are grounded at G101 and G100. The rear turn signals are grounded at G400 and G401.

On the export vehicle, the rear turn signal lamps are separate amber lamps utilizing single filament bulbs grounded at G400 and G401. There are also amber side repeater lamps on each fender which are grounded at G101 and G100. The front side marker lamps stay on steady and do not flash alternately with the turn signals as the domestic vehicle does due to they are grounded directly to G101 and G100.

The STOP/HAZ fuse in the IP fuse block supplies battery positive voltage to the normally open stoplamp switch. When the driver presses the brake pedal, the switch contacts close and battery positive voltage is supplied to the multifunction turn signal switch. The current flow is now to the stoplamps which are grounded at G400 and G401. The center high mounted stoplamp (CHMSL) is grounded at G400.

The TURN-B/U fuse in the IP fuse block supplies battery positive voltage to the normally open backup lamp switch. When driver places the gear selector lever is in the REVERSE position, the backup lamp switch closes and the current flow is from the backup lamp switch to the backup lamps. The backup lamps are grounded at G400 and G401.