Cadillac 2007 CTS Owner's Manual page 385

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, do the following:
1. Open the hood. See Hood Release on
page 341 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) the width of
the vehicle at the wall where it was marked
it 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 aimed. This should
allow only the beam of light from the headlamp
being aimed to be seen on the flat surface.
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