GMC 2011 Terrain Owner's Manual page 322

10-32 Vehicle Care
To adjust the vertical aim, do the
following:
1. Open the hood. See Hood on
page 10 5 for more information.
2. Locate the aim dot on the lens of
the low beam headlamp.
3. Measure the distance from the
ground to the aim dot on the
low beam headlamp. Record the
distance.
4. At the wall, measure from
the ground upward (A) to the
recorded distance from
Step 3 and mark it.
5. Draw or tape a horizontal line (B)
on the wall the width of the
vehicle at the height of the mark
in Step 4.
Notice: Do not cover a headlamp
to improve beam cut-off when
aiming. Covering a headlamp may
cause excessive heat build-up
which may cause damage to the
headlamp.
6. Turn on the low-beam
headlamps and place a piece
of cardboard or equivalent in
front of the headlamp not being
adjusted. This allows only the
beam of light from the headlamp
being adjusted to be seen on the
flat surface.