GM Service Manual Online
For 1990-2009 cars only

Adjustment Procedure

The front foglamps can be adjusted by turning the adjustment screws.

The adjustment thumb screw is located on the top inboard corner of the foglamp.

Use the following guidelines in order to adjust the aim:

    • Turn the adjustment screw clockwise in order to raise the aim.
    • Turn the screw counterclockwise in order to lower the aim.

The front foglamps may be adjusted using the screen method. Refer to Headlamp Aiming for information on setting up an aiming screen.

Use the following procedure in order to aim the foglamps using the screen method:

  1. Position the vehicle on a level surface, squarely in front of the screen, so that the front surfaces of the foglamps are 7.62 m (25 ft) from the aiming screen.
  2. Ensure that all vehicle components are properly installed, if other work has been performed on the vehicle.
  3. Ensure that the vehicle has ½ tank of fuel or less.
  4. Close all of the vehicle doors.
  5. Rock the vehicle to stabilize the suspension.

  6. Object Number: 277181  Size: SH
  7. Adjust the height of the horizontal tape line (3) on the aiming screen so that the distance between the line and the floor is 101.6 mm (4 in) LESS than the distance between the floor and the horizontal centerline (5) of the front foglamps.
  8. Turn on the front foglamps, and block the light from the headlamps, if necessary.
  9. Important: The top edge of the high intensity zones must be at or below the level of the horizontal tape line.

  10. Observe the top edge of the high intensity zones on the aiming screen.
  11. Using the adjusting screw, adjust the foglamps so that the top edge of the high intensity light zone is at or just below the horizontal tape line.