GM Service Manual Online
For 1990-2009 cars only

When it is dark enough outside, your Automatic Headlamp System will turn on your headlamps at the normal brightness along with other lamps such as the taillamps, sidemarker, parking lamps and the instrument panel lights. The radio lights will also be on.

Your vehicle is equipped with a light sensor on the top of the instrument panel. Be sure it is not covered or the system will be on whenever the ignition is on.

The system may also turn on your lights when driving through a parking garage, heavy overcast weather or a tunnel. This is normal.

There is a delay in the transition between the daytime and nighttime operation of the Daytime Running Lamps (DRL) and the automatic headlamp systems, so that driving under bridges or bright overhead street lights does not affect the system. The DRL and automatic headlamp system will only be affected when the light sensor sees a change in lighting lasting longer than the delay.

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 the full bright position.

To idle your vehicle with the automatic headlamp system off, start your vehicle and turn the headlamp switch to the off position. The switch will automatically return to the AUTO position. The automatic headlamp system will stay off until you turn the switch to the off position again as explained in "Headlamps". See Headlamps . This feature is not available for vehicles first sold in Canada.