GM Service Manual Online
For 1990-2009 cars only

Calibration Criteria

Headlamp module calibration must be performed after a ride height sensor or headlamp module has been serviced. The calibration procedure will set the "centered" value for the front and rear ride height sensors. This value is used by the headlamp module to determine the proper amount of headlamp adjustment required for vehicle conditions. The following criteria must be met before preforming the calibration procedure:

    • The vehicle must be placed on a flat level surface.
    • There must be no occupants in the vehicle.
    • Any additional cargo weight in the rear compartment must be removed.
    • All doors must be closed.

Calibration Procedure

  1. Install a scan tool.
  2. Clear All DTCs before proceeding.
  3. Reprogram the Headlamp Control Module, refer to Service Programming System (SPS).
  4. Navigate to the Vehicle Control Systems menu.
  5. Select Module Setup menu item.
  6. Select Headlamp Control Module menu item.
  7. Select Recalibrate leveling Sensor and follow the directions displayed on the screen.
  8. Once the calibration procedure has been completed, verify the calibration by selecting the calibration procedure on the scan tool an additional time. If mechanical adjustments are required, refer to Headlamp Aiming.