Buick 2004 Park Avenue - Manual (Page 293)

Headlamp Aiming
The headlamp aiming device is under the hood, directly
behind the headlamps.
Your vehicle has a headlamp system equipped with
horizontal and vertical aim indicators. The aim has been
pre-set at the factory and should need no further
adjustment. This is true even though your vertical and
horizontal aim indicators may not fall exactly on the
“0” (zero) marks on their scales.
If your vehicle is damaged in an accident, the headlamp
aim may be affected. Aim adjustment may be necessary
if it is difficult to see lane markers (for horizontal
aim), or if oncoming drivers flash their high beams at
you (for vertical aim). If you believe your headlamps
need to be re-aimed, we recommend that you take it to
your dealer for service; however, it is possible for
you to re-aim your headlamps as described in the
following procedure.
Notice: To make sure your headlamps are aimed
properly, read all the instructions before beginning.
Failure to follow these instructions could cause
damage to headlamp parts.
5-49