Automatic Level Control Sensor Adjustment

1. Perform the trim height inspection. Refer to TRIM HEIGHT INSPECTION PROCEDURE .
2. Load 250-300 lbs into the rear of the passenger compartment, (enough load to activate the automatic level control air compressor, distributed evenly from left to right.
3. Turn ON the ignition, with the engine OFF. Wait for approximately one minute for the Air Replenishment Cycle to complete.
4. Turn OFF the ignition.
5. Repeat the trim height inspection. Refer to TRIM HEIGHT INSPECTION PROCEDURE . Do not adjust the automatic level control sensor if the vehicle is within the correct trim height range.
6. Raise and suitably support the vehicle. Refer to LIFTING AND JACKING THE VEHICLE . Ensure that the vehicle is roughly level and supported by the rear wheels or axle.
   Fig 1: Loosening Lock Bolt Clamping Metal Actuating Arm To Plastic Actuating Arm

   Courtesy of GENERAL MOTORS CORP.
   NOTE: When diagnosis or repair requires raising the vehicle on a hoist, it is important that the rear axle remains in the normal trim height position at all times. Therefore, the hoists should support the rear wheels or axle housing. Use two additional jack stands to support the rear axle when a frame contact hoist is used or damage to the auto level control air compressor could occur.
7. Inspect the automatic level control sensor for damage. Ensure that the automatic level control sensor link is properly connected.

   Important:  The link must be attached to the height sensor arm and the suspension control arm during the adjustment.

8. Loosen the lock bolt (5) that clamps the metal actuating arm (4) to the plastic actuating arm.
9. To increase the trim height, move the plastic arm up in relation to the metal arm. To decrease the trim height, move the plastic arm down in relation to the metal arm.
   NOTE: Refer to FASTENER NOTICE .
10. Tighten the lock bolt.

    Tighten 

    Tighten the lock bolt to 5 N.m (44 lb in).

11. Perform the trim height inspection. Refer to TRIM HEIGHT INSPECTION PROCEDURE .

Optional Sensor Adjustment Method 

Special Tool J 34825  may be used for sensor adjustment. Instructions are provided with the tool.