GM Service Manual Online
For 1990-2009 cars only

To adjust the horizontal aim, do the following:

  1. Open the hood. See Hood Release for more information.
  2. Locate the horizontal aiming screw (A).

  3. Object Number: 810593  Size: B2
  4. Turn the horizontal aiming screw (A) until the indicator (B) is lined up with zero.

Once the horizontal aim is adjusted, then adjust the vertical aim.