Buick 2009 Enclave Owner's Manual page 317

The vehicle should be:
•
Placed so the headlamps are 25 ft. (7.6 m) from a
light colored wall.
•
On a perfectly level surface which is level all the
way to the wall.
•
Be placed so it is at a right angle to the wall.
•
Clear of any snow, ice or mud on it.
•
Be fully assembled, with the tires properly inflated
and all other work stopped while headlamp aiming
is being done.
•
Be normally loaded with a full tank of fuel, with the
spare tire in its proper location, and one person or
160 lbs (75 kg) on the driver seat.
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.
Locate the vertical headlamp aiming screws under
the hood near the headlamps.
The adjustment screw can be turned with a 6 mm
male hex.
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