GM Service Manual Online
For 1990-2009 cars only

    Object Number: 295903  Size: SH
  1. Ensure that the aiming area has the following characteristics:
  2. • A dark location
    • Large enough area in order to accommodate the vehicle and an additional 7.6 m (25 ft) measured from the face of the headlamp to the visual screen (5)
    • Ensure that the floor is level with the bottom of the screen.
    • Compensate for a floor that is not level.
  3. Ensure that the aiming screen (5) has the following characteristics:
  4. • Is 1.52 m (5 ft) high by 3.66 m (12 ft) wide
    • Has a matte white surface
    • Is well shaded from outside light
    • Is properly adjusted to the floor on which the vehicle stands
    • Has the following lines:
       - A vertical centerline (8)
       - 2 laterally adjustable vertical tapes (9)
       - A vertically adjustable horizontal tape (3)
       - If a regular commercial aiming screen is not available, the screen may consist of a vertical wall having a clear uninterrupted area approximately 1.83 m (6 ft) high by 3.66 m (12 ft) wide, finished with a washable non-gloss white paint.

    Important: Use the following procedure when checking different vehicles:

       • Adjust the horizontal line or tape (3) on the screen for each vehicle that you check.
            Vehicles of the same model and year will have different standing height for the headlamps.
       • Align the screen parallel with the rear axle.
       • Draw a horizontal line that is perpendicular to the centerline of the screen and pass the line through the center point between the headlamps (8).
       • Paint a reference line (7) on the floor once you have set the screen in a permanent location.
            Use the reference line in order to identify the proper location of the headlamps while you are aiming the headlamps.

  5. Use the following procedure in order to check for beam aim:
  6. 3.1. Completely assemble all of the components on the vehicle.
    3.2. Verify that the fuel load is at one-half tank or less.
    3.3. Ensure that the only other load in the vehicle is the driver.
    3.4. Position the vehicle square with the aiming screen.
    3.5. Ensure that the headlamps are directly over the reference line (7) that has been painted on the floor.
    3.6. Locate the vertical centerline (2) on the aiming screen (5) so that the aiming screen is in line with the center of the vehicle (8).
    3.7. Close the doors.
    3.8. Rock the vehicle sideways in order to stabilize the suspension.

    Object Number: 295898  Size: SH
  7. Switch the headlamps ON to low beam.
  8. Observe the left and the top edges of the high intensity zone on the screen.
  9. Adjust the horizontal aim by using the horizontal adjusting screw, if the left edge is beyond the following specifications:
  10. • 102 mm (4 in) right (2) of the straight ahead position (3,5)
    • 102 mm (4 in) left (4) of the straight ahead position (3,5)
  11. Adjust the vertical aim by using the vertical adjusting screw, if the top edge is beyond the following specifications:
  12. • 102 mm (4 in) above (7) the horizontal line (1).
    • 102 mm (4 in) below (6) the horizontal line (1).