GM Service Manual Online
For 1990-2009 cars only

To properly prepare the vehicle for vertical headlamp aiming, see Headlamp Aiming for more information.

Notice: Horizontal aiming must be performed before making any adjustments to the vertical aim. Adjusting the vertical aim first will result in an incorrect headlamp aim.

To adjust the vertical aim:

  1. Open the hood. See Hood Release for more information.
  2. Locate the aim dot on the inner projector lens of the low-beam headlamp.
  3. Measure the distance from the ground to the aim dot on each low-beam headlamp. Record this distance.

  4. Object Number: 1656201  Size: B2
  5. At the wall or other flat surface, measure from the ground upward (A) to the recorded distance from Step 3 and mark it.
  6. 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.

  7. Draw or tape a horizontal line (B) on the wall or flat surface the width of the vehicle at the height of the mark in Step 4.
  8. Turn on the low-beam headlamps and place a piece of cardboard 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.
  9. Locate the vertical headlamp aiming screws, which are under the hood near each headlamp assembly.
  10. The adjustment screw can be turned with a 6 mm male hex.


    Object Number: 1215869  Size: A2
  11. Turn the vertical aiming screw until the headlamp beam is aimed to the horizontal tape line.
  12. The top edge of the cut-off should be positioned at the bottom edge of the horizontal tape line.

  13. Object Number: 1656218  Size: B2
  14. Make sure that the light from the headlamp is positioned at the bottom edge of the horizontal tape line. The lamp on the left (A) shows the correct headlamp aim. The lamp on the right (B) shows the incorrect headlamp aim.
  15. Repeat Steps 7 through 9 for the opposite headlamp.