Automatic Headlamp System - GMC Sierra Classic 2007 Owner's Manual

Automatic Headlamp System

When it is dark enough outside, the automatic
headlamp system will turn on the headlamps at the
normal brightness, along with the taillamps,
sidemarker, parking lamps, and the instrument
panel lights. The radio back lighting will also
be dimly lit.
To turn off the automatic headlamp system, turn
the exterior lamps switch to the off position.
Turning off the automatic headlamp system with
the headlamp switch is not available for vehicles
first sold in Canada.
Your vehicle has a light sensor located on the top
of the instrument panel in the defroster grille
that regulates when the automatic headlamps turn
on. Be sure it is not covered, or the headlamps
will come on whenever the ignition is on.
The system may also turn on the headlamps 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.
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The DRL and automatic headlamp system will only
be affected when the light sensor detects 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 approximately one minute for the automatic
headlamp system to change to DRL if it is
bright enough 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. See Instrument
Panel Brightness on page 224.
To idle your vehicle with the automatic headlamp
system off, turn the control to the off position.
You may be able to turn off your Automatic
Headlamp System. See Daytime Running Lamps
(DRL) on page 221 for more information.
Your headlamps will also stay on after you exit the
vehicle. You can program this feature using the
Driver Information Center (DIC). See DIC Vehicle
Customization on page 279.
As with any vehicle, you should turn on the
regular headlamp system when needed.