GM Service Manual Online
For 1990-2009 cars only

Exterior Lamps

The exterior lighting system includes the following components:

    • Headlamps (high and low beam)
    • Front fog lamps
    • Front park/turn signal lamps
    • Tail/rear turn signal lamps
    • Front sidemarker lamps
    • Rear sidemarker lamps
    • High-mounted stoplamp
    • Backup lamps
    • License lamp

This system also includes all wiring controls and related hardware required for the operation of these lamps.

Headlamps

Low Beam Operation

The headlamp switch is used to operate the low beam headlamps. The headlamp switch is located on the left side of the instrument panel. Turning the knob of the headlamp switch to the furthest position to the right will turn ON the low beam headlamps.

A warning tone will sound as a reminder to turn OFF the headlamp switch, when the ignition switch is in the OFF, LOCK or ACC positions and the driver's door is opened.

High Beam Operation

The turn signal/multifunction switch is used to operate the high beam headlamps. The turn signal/multifunction switch is located on the LH side of the steering column. Pulling the lever of the turn signal/multifunction switch toward you until the rear detent position can be felt and then releasing the lever, will cause the headlamp operation to switch between low and high or high and low beam, depending upon the starting point.

High Beam Indicator

During operation of the high beam headlamps, the high beam indicator located on the instrument panel cluster will be illuminated.

Flash-to-Pass Operation

The turn signal/multifunction switch is also used to operate the high beam headlamps in the flash-to-pass mode. Pulling the lever of the turn signal/multifunction switch toward you slightly will activate the high beam headlamps. Holding the lever in this position will maintain high beam headlamp operation for as long as needed. When the lever is released, the previous headlamp operation will resume. Flash-to-pass may be used whether the headlamps are ON or OFF.

Daytime Running Lamps (DRL)

The Daytime Running Lamp (DRL) system has two primary components; a DRL control module, (located in the instrument panel) and an ambient light sensor, (located on the top of the instrument panel upper trim plate along the base of the windshield).

The DRL system operates either the high beam headlamps at a reduced brightness, or the low beam headlamps at normal intensity along with the park/sidemarker/license lamps and instrument panel lamps, when the following conditions exist:

    • The ignition switch is ON
    • The headlamp switch is OFF
    • The park brake is released

To temporarily disable the DRL system while idling the vehicle, if necessary:

  1. Turn the ignition switch to the OFF or LOCK position.
  2. Set the park brake.
  3. Start the engine and allow it to idle.

The DRL system will remain disabled until the park brake is released.

Daytime Operation

When the ambient light sensor detects that sufficient lighting conditions exist outside the vehicle, the DRL control module will operate the high beam headlamps at a reduced brightness.

Nighttime Operation

When the ambient light sensor detects that low lighting conditions exist outside the vehicle, the DRL control module will operate the low beam headlamps at normal intensity along with the park/sidemarker/license lamps and instrument panel lamps.

Fog Lamps -- Front

The front fog lamps are located in the front bumper fascia beneath the headlamp assemblies. The front fog lamp switch is located above the headlamp switch on the left side of the instrument panel. Pressing the right side of the fog lamp switch button will turn the fog lamps ON, as long as the parking lamps are on. When the fog lamps are ON, an indicator on the fog lamp switch will illuminate. Pressing the left side of the switch will turn the fog lamps OFF.

Turn Signal Lamps

The front turn signal lamps are made up of the front park/turn signal lamps and the front sidemarker lamps, both located on the outboard ends of the headlamp assemblies. The rear turn signal lamps are located in the taillamp assemblies. The front turn signal lamps flash with the rear turn signal lamps when a turn is initiated through using the turn signal/multifunction lever. The front turn signal lamp and the front sidemarker lamp will flash in unison if the park lamps are OFF, but the lamps will flash alternately if the park lamps are ON. The turn signals will operate only with the ignition switch in the RUN position and will not operate during hazard flasher operation.

Park/Sidemarker Lamps

The front park lamps are made up of the front park/turn signal lamps and the front sidemarker lamps, both located on the outboard ends of the headlamp assemblies. The rear park lamps are made up of the rear park/turn signal lamps and the rear sidemarker lamps located in the taillamp assemblies.

The headlamp switch is used to operate the park lamps. The headlamp switch is located on the left side of the instrument panel. Turning the knob of the headlamp switch to the middle position will turn ON the park lamps.

A warning tone will sound as a reminder to turn OFF the headlamp switch, when the ignition switch is in the OFF, LOCK or ACC positions and the driver's door is opened.

Stoplamps

There are stoplamps incorporated into the taillamp assemblies as well as a high-mounted stoplamp, located on the rear shelf, centered along the lower edge of the rear window. The stoplamps operate whenever the brake pedal is depressed.

Backup Lamps

The backup lamps are located in the taillamp assemblies. The back-up lamps operate when the ignition switch is in the RUN position and the transaxle range selector lever is in REVERSE.

License Lamp

The license lamp is located in the rear bumper fascia just above the license plate opening. The license lamp is in operation whenever the headlamp switch is in either ON position.

Interior Lamps

The interior lighting system includes the following components:

    • Instrument panel cluster/radio/switch illumination lamps
    • Overhead console (courtesy/reading) lamps
    • Side rail lamps
    • Vanity mirror lamps
    • Console shift control indicator lamp (with floor console)
    • Instrument panel compartment lamp
    • Ashtray lamp
    • Front side door courtesy lamps
    • Rear compartment lamp

This system also includes all wiring controls and related hardware required for the operation of these lamps.

Instrument Panel Cluster/Radio/Switch Illumination Lamps

The instrument panel cluster, the radio and the interior switches (with illumination provisions), are in operation whenever the headlamp switch is in either ON position. The brightness level or dimming of these lamps is controlled by the instrument panel dimmer switch, which is incorporated into the headlamp switch.

Overhead Console (Courtesy/Reading) Lamps

The overhead console reading/courtesy lamps are integrated into the overhead console assembly, mounted to the headliner, above and slightly forward of the front seats. The overhead console (courtesy) lamps are activated whenever a door is opened or whenever the IP dimmer lamp switch (headlamp switch) is rotated past the maximum brightness setting to the next detent position.

The overhead console (reading) lamps may also be activated and used individually by depressing the corresponding reading lamp switch, also located on the overhead console. Depressing the lamp switch again will turn the reading lamps OFF.

Side Rail Lamps

The side rail lamps are located above the outboard sides of the back seat, mounted to the headliner. The side rail lamps are activated whenever a door is opened or whenever the IP dimmer lamp switch (headlamp switch) is rotated past the maximum brightness setting to the next detent position. The side rail lamps may be operated individually (sedans only) by depressing the side rail lamp switch located next to the lens.

Vanity Mirror Lamps

The vanity mirror lamps are integrated into the mirror housing on the sunshade assembly. The vanity mirror lamps are activated whenever the mirror cover is opened.

Console Shift Control Indicator Lamp

The console shift control indicator lamp is integrated into the shift control indicator plate. The indicator lamp is activated whenever the headlamp switch is in either ON position

Instrument Panel Compartment Lamp

The instrument panel (IP) compartment lamp is located in the upper RH side of the IP compartment. The IP compartment lamp switch is located in the IP compartment support panel, behind the LH edge of the IP compartment door. The compartment lamp is activated whenever the IP compartment door is opened.

Ashtray Lamp

The ashtray lamp is located on the top of the ashtray bracket, just above the ashtray drawer. The ashtray lamp is activated whenever the headlamp switch is in either ON position.

Side Door Courtesy Lamps -- Front

The front side door courtesy lamps are located on the door trim panels near the rearward edge of the front doors. The side door courtesy lamps are activated whenever a door is opened or whenever the IP dimmer lamp switch (headlamp switch) is rotated past the maximum brightness setting to the next detent position.

Rear Compartment Lamp

The rear compartment lamp is located on the underside of the rear shelf support. The rear compartment lamp operates whenever the rear compartment lid is raised.