Air Spring Sensor Calibration

CAUTION: A sudden release of pressure may cause personal injury or damage to the vehicle. The air suspension system is under pressure until the air supply lines are disconnected. Use the following precautions when servicing the air suspension system:

Wear gloves, ear protection, and eye protection.
Wrap a clean cloth around the air supply lines.

NOTE: Depressurize the air suspension system only after the rear axle is supported and is set between D- Height and Full Jounce.

IMPORTANT: Remove the air suspension system fuse before working on the rear suspension components or the rear axle. Failure to remove the air suspension system fuse could cause the calibration of the air suspension leveling sensor to change and the air suspension system not to function properly.

Remove the air suspension system fuse.
Raise and support the vehicle. Refer to LIFTING AND JACKING THE VEHICLE in General Information.
Raise and support the rear axle at the designed D height. Refer to TRIM HEIGHT SPECIFICATIONS in Suspension General Diagnosis.
Remove the rear tire and wheels. Refer to TIRE AND WHEEL REMOVAL AND INSTALLATION in Tires and Wheels.
Remove the air compressor mounting bolts from the frame and support air compressor.

Fig 1: Removing/Installing Air Compressor Mounting Bolts
Courtesy of GENERAL MOTORS CORP.
Loosen both of the air supply line connections at the air compressor in order to depressurize the air springs.
Support the rear axle and set the rear axle to proper D height. Refer to TRIM HEIGHT SPECIFICATIONS in Suspension General Diagnosis.
Loosen the air spring level sensor to the frame mounting bolts.

Fig 2: Removing/Installing Air Spring Level Sensor Mounting Bolts
Courtesy of GENERAL MOTORS CORP.

NOTE: Failure to remove the air suspension auto level control sensor locating pin before the rear axle support is removed will cause damage to the air suspension auto level control sensor.
Install air spring level sensor locating pin.
Use proper size drill bit that fits snugly.

Fig 3: Removing/Installing Air Spring Level Sensor Locating Pin
Courtesy of GENERAL MOTORS CORP.

NOTE: Refer to FASTENER NOTICE in Cautions and Notices.

IMPORTANT: Do not remove the air spring level sensor locating pin until the air spring level sensor has been properly aligned and the proper D height has been measured and maintained. Refer to TRIM HEIGHT SPECIFICATIONS in Suspension General Diagnosis.
Tighten the air spring level sensor to the frame mounting bolts.
Tighten: Tighten the air spring level sensor to the frame mounting bolts to 8 N.m (71 lb in).

Fig 4: Removing/Installing Air Spring Level Sensor
Courtesy of GENERAL MOTORS CORP.

NOTE: Failure to remove the air suspension auto level control sensor locating pin before the rear axle support is removed will cause damage to the air suspension auto level control sensor.
Remove the air spring level sensor locating pin.

Fig 5: Removing/Installing Air Spring Level Sensor Locating Pin
Courtesy of GENERAL MOTORS CORP.

IMPORTANT: Check the air supply lines for deep scores or cuts. If the air supply lines are damaged the lines must be replaced. Refer to Air Suspension Air Line Replacement .
Tighten the air supply lines to the air compressor. Do not over tighten.
Tighten: Tighten the air supply lines to the air compressor to 2.25 N.m (20 lb in).

Fig 6: Removing/Installing Air Compressor Mounting Bolts
Courtesy of GENERAL MOTORS CORP.
Install the air compressor to frame mounting bolts.
Tighten: Tighten the air compressor mounting bolts to the frame to 20 N.m (15 lb ft).
Install the rear tire and wheels. Refer to TIRE AND WHEEL REMOVAL AND INSTALLATION in Tires and Wheels.
Remove the rear axle support.
Lower the vehicle.
Install the air suspension system fuse.
Start the vehicle and run for approximately 1 minute to ensure that the air suspension system is functioning properly.
Check the D height. Refer to TRIM HEIGHT INSPECTION PROCEDURE in Suspension General Diagnosis.