Hummer 2006 H2 - Manual (Page 156)

When the DRL are on, only your DRL lamps will be on.
The taillamps, sidemarker and other lamps won’t be
on. The instrument panel won’t be lit up either.
When it begins to get dark, the automatic headlamp
system will switch from DRL to the headlamps.
As with any vehicle, you should turn on the regular
headlamp system when you need it.
Automatic Headlamp System
When it is dark enough outside and the headlamp
switch is in AUTO, your automatic headlamp system will
turn on your headlamps at the normal brightness
along with other lamps such as the taillamps,
sidemarker, parking lamps, roof marker lamps and the
instrument panel lights. The radio lights will also be dim.
To turn off the automatic headlamp system, turn the
exterior lamps switch to the off position and then
release. Turning off the automatic headlamp system
with the headlamp switch is not available for vehicles
first sold in Canada. For vehicles first sold in Canada,
you can turn off the automatic headlamp system
when parked at night by applying the parking brake
before starting your vehicle. The headlamps will remain
off once the vehicle is started for as long as you are
parked. If you release the parking brake, the lights will
turn on. If the parking brake is not released before you
begin to drive, the exterior lamps will turn on above
2 mph (3.2 km/h).
Your vehicle has a light sensor located 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 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. 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 approximately
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. See Instrument Panel
Brightness on page 3-17.
3-16