GM Service Manual Online
For 1990-2009 cars only

The exterior lamp switch on the turn signal/multifunction lever operates the headlamps.

The exterior lamp switch has three positions:

OFF: Turn the switch to this position to turn off all lamps, except the Daytime Running Lamps (DRL).

(Parking Lamps): Turn the switch to this position to turn on the parking lamps, together with the following:

    • Taillamps
    • Parking Lamps
    • Sidemarker Lamps
(Headlamps): Turn the switch to this position to turn on the headlamps, together with the previously listed lamps.

Headlamps Doors


Object Number: 807642  Size: B3

The headlamp doors are designed to open when you turn the headlamps on, and close when you turn the headlamps and parking lamps off. If you turn the headlamps on, then turn back to the parking lamps setting, the headlamp doors will stay open.

You can open the doors manually using the knob next to the headlamp assembly. Turn the knob counterclockwise until the doors are open. Turn the knob clockwise to close the doors manually.

The headlamp doors should be open when driving in icy or snowy conditions to prevent the doors from freezing closed and when washing the vehicle to help clean the headlamps.

Notice: If the hood comes into contact with the headlamp doors when you raise the hood, you could damage the hood and/or the headlamp doors. Always close the headlamp doors before opening the hood.

Daytime Running Lamps

Daytime Running Lamps (DRL) can make it easier for others to see the front of your vehicle during the day. DRL can be helpful in many different driving conditions, but they can be especially helpful in the short periods after dawn and before sunset. Fully functional daytime running lamps are required on all vehicles first sold in Canada.

The DRL system will make the front turn signal lamps come on when the following conditions are met:

    • The ignition is on,
    • the exterior lamp switch is off and
    • the parking brake is released.

When the DRL are on, only the front turn signal lamps will be on. The headlamps, taillamps, sidemarker and other lamps will not be on. Your instrument panel will not be lit up either.

To idle the vehicle with the DRL off, set the parking brake while the ignition is in OFF. Then start the vehicle. The DRL, headlamps and parking lamps will stay off until you release the parking brake.

As with any vehicle, you should turn on the regular headlamp system when you need it.

Fog Lamps


Object Number: 807287  Size: B3

Your vehicle may have this feature. Use the fog lamps for better vision in foggy or misty conditions. Your parking lamps or low-beam headlamps must be on or the fog lamps will not work.

To turn the fog lamps on, press the button located on the instrument panel, to the left of the steering column. A light in the button will come on while the fog lamps are on. Press the button again to turn the fog lamps off.

Twilight Sentinel® (Optional in United States, Standard in Canada)

Twilight Sentinel® can turn your lamps on and off for you. A light sensor on top of the instrument panel makes the Twilight Sentinel® work, so be sure it is not covered.

You can customize your vehicle to turn Twilight Sentinel® on or off, except for vehicles first sold in Canada. See Driver Information Center (DIC) to turn this feature on or off.

When Twilight Sentinel® is turned on, you will see the following happen:

    • When it is dark enough outside, the front turn signal lamps (DRL) will go off, and the headlamps and parking lamps will come on. The other lamps that come on with headlamps will also come on.
    • When it is bright enough outside, the headlamps will go off, and the front turn signal lamps (DRL) will come on, as long as the exterior lamp switch is in the OFF position.

If you start your vehicle in a dark garage, the automatic headlamp system will come on immediately. Once you leave the garage, it will take about one minute for the automatic headlamp system to change to DRL if it is light outside. During that delay, your instrument panel cluster may not be as bright as usual. Make sure your instrument panel brightness control is in full bright position. See "Instrument Panel Brightness Control" under Interior Lamps .

With Twilight Sentinel® turned on, you can idle the vehicle with the lamps off, even when it is dark outside. First set the parking brake while the ignition is in OFF. Then start the vehicle. The lamps will stay off until you release the parking brake.

Twilight Sentinel® also provides exterior illumination as you leave the vehicle. If Twilight Sentinel® has turned on the lamps when you turn off the ignition, your lamps will remain on until:

    • The exterior lamp switch is moved from OFF to the parking lamp position, or
    • a delay time that you select has elapsed.

See Driver Information Center (DIC) to select the delay time that you want. You can also select no delay time.

If you turn off the ignition with the exterior lamp switch in the parking lamp or headlamp position, the Twilight Sentinel® delay will not occur. The lamps will turn off as soon as the switch is turned off.

As with any vehicle, you should turn on the regular headlamp system when you need it.