GM Service Manual Online
For 1990-2009 cars only

Aiming Screen Area


Object Number: 418400  Size: SH

The area shall consist of a level surface large enough to allow for a vehicle and an additional 7.62 m (25 ft) as measured from the face of the headlamps to the aiming screen.


Object Number: 418380  Size: SH

The screen shall be a wall or flat surface at least 1.52 m (5 ft) high by 3.66 m (12 ft) wide with a matte white surface well-shaded from extraneous light, and 90 degrees to the floor. The screen shall be provided with a permanent vertical reference line 2 feet from the left edge of the screen, 2 laterally adjustable vertical tapes, and one vertically adjustable horizontal tape.

After the aiming screen has been set up and located, paint or tape a reference line on the floor 15.24 m (50 ft) from the vertical reference line on the screen. This line shall be perpendicular to the aiming screen and a mark placed at 7.62 m (25 ft) from the screen.

Aiming Procedure

  1. Remove any snow, ice, or mud from the vehicle.
  2. Align the vehicle left tires with the reference line extending from the screen with the headlamps aligned with the reference line.
  3. Stop all unnecessary operations or work on the vehicle that affects the vehicle trim.
  4. Completely assemble all the components to the vehicle.
  5. The vehicle should have cargo or loading representative of normal vehicle use.
  6. Close the doors.
  7. Verify that the tires are inflated to the proper tire pressure.
  8. Rock the vehicle sideways to stabilize the suspension.
  9. Measure from the reference line on the floor to the left headlamp bulb aim dot on the headlamp.
  10. At the screen, measure from the reference line on the floor and place the vertical tape at the measured distance.
  11. Measure from the reference line on the floor to the right headlamp bulb aim dot on the headlamp.
  12. At the screen, measure from the reference line on the floor and place the vertical tape at the measured distance.
  13. Measure between the left and right headlamp vertical tape on the screen.
  14. Divide the measured amount in half and mark on the screen. This is the centerline of the vehicle.
  15. At the screen, measure from the floor and place the horizontal tape at 61 cm (24 in).
  16. Measure 88.9 mm (3.5 in) left of the center line and mark on screen.
  17. Hang a trouble light along the aiming screen at the measured location.
  18. Cover the windshield with a fender cover or equivalent.
  19. Turn on headlamps and night vision.
  20. Important: When aligning night vision camera leave a 1 mm (0.04 in) minimum clearance between the camera and the secondary hood latch rivet.

  21. Have an assistant turn the adjusting screws.
  22. Sight the trouble light to the center of the HUD display