Automatic Headlamp System - GMC 2006 Envoy Owner's Manual

Automatic Headlamp System

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.
3-16
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.
Only vehicles first sold in the United States can idle with
the automatic headlamp system off. To idle with the
automatic headlamp system off, set the parking brake
while the ignition is off. Then start your vehicle. The
automatic headlamp system will stay off until you release
the parking brake, shift out of park or turn the exterior
lamp control to the off position (US vehicles only)
as described previously.