GM Service Manual Online
For 1990-2009 cars only

The optical headlamp aiming system has been preset at the factory and should need no further adjustment

However, if the vehicle is damaged adjustment may be necessary.

If oncoming vehicles flash their high beams at you, this may also mean the vertical aim needs to be adjusted.

It is recommended that the vehicle is taken to your dealer/retailer for service if the headlamps need to be re-aimed. It is possible however, to re-aim the headlamps as described.

The vehicle should:

    • Be placed so the headlamps are 25 ft. (7.6 m) from a light colored wall.
    • Have all four tires on a perfectly level surface which is level all the way to the wall.
    • Be placed so it is at a right angle to the wall.
    • Not have any snow, ice, or mud on it.
    • Be fully assembled and all other work stopped while headlamp aiming is being done.
    • Have a full tank of fuel and one person or 160 lbs (75 kg) on the driver seat.
    • Have all tires properly inflated.

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 on the headlamps:

  1. Open the hood. Hood Release .

  2. Object Number: 1968823  Size: G1
  3. Locate the aim dot on the lens of the low-beam headlamp.
  4. Record the distance from the ground to the aim dot on the low-beam headlamp.

  5. Object Number: 1988140  Size: G1
  6. At the wall, measure from the ground upward (A) to the recorded distance from Step 3 and mark it.
  7. Draw or tape a horizontal line (B) on the wall the width of the vehicle at the height of the mark in Step 4.
  8. 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.

  9. Turn on the low-beam headlamps and place a piece of cardboard or equivalent in front of the headlamp not being adjusted. Do not place it directly on the headlamp. This allows only the beam of light from the headlamp being adjusted to be seen on the flat surface.
  10. Driver Side (Passenger Side Similar)


    Object Number: 2023495  Size: G1
  11. Locate the vertical headlamp aiming screws, which are under the hood near each headlamp assembly.
  12. The adjustment screw can be turned with a 6 mm socket wrench.

  13. Turn the vertical aiming screw clockwise or counterclockwise until the headlamp beam is aimed to the horizontal tape line.

  14. Object Number: 1988142  Size: G1
  15. 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.
  16. Repeat Steps 7 through 9 for the opposite headlamp.