GMC 2008 Yukon XL Denali, Owner'S Manual, Page: 386 / 502

Headlamp Aiming
The vehicle has a visual optical headlamp aiming
system. The aim of the headlamps have been preset
at the factory and should need no further adjustment.
However, if the vehicle is damaged in a crash, the aim
of the headlamps may be affected and adjustment may
be necessary.
If oncoming vehicles flash their high beams at you, this
may mean the vertical aim of your headlamps needs
to be adjusted.
It is recommended that the vehicle is taken to your
dealer/retailer for service if the headlamps need to
be adjusted. It is possible however, to re-aim the
headlamps as described.
The vehicle should:
•
Be placed so the headlamps are 25 ft. (7.6 m) from
a light colored wall.
•
Have all four tires on a level surface which is level
all the way to the wall.
•
Be placed so it is perpendicular to the wall.
•
Not have any snow, ice, or mud on it.
•
Be fully assembled and all other work stopped while
headlamp aiming is being performed.
•
Normally loaded with a full tank of fuel and one
person or 160 lbs (75 kg) sitting on the driver seat.
•
Have the tires properly inflated.
•
Have the spare tire is in its proper location in the
vehicle.
Headlamp aiming is done with the vehicle’s low-beam
headlamps. The high-beam headlamps will be correctly
aimed if the low-beam headlamps are aimed properly.
To adjust the vertical aim:
1. Open the hood. See Hood Release on page 5-10
for more information.
2. Locate the aim dot on the lens of the low-beam
headlamp.
3. Record the distance from the ground to the aim dot
on the low-beam headlamp.
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