GM Service Manual Online
For 1990-2009 cars only

Step

Action

Normal Result(s)

Abnormal Result(s)*

1

Turn the ignition switch to the ON position.

After approximately 35-55 seconds, the air compressor runs for 3-5 seconds. NOTE: This action may be overridden by the height sensor if a load has been added or removed from the vehicle.

    • The air compressor cycles on and off frequently. If no air leaks are present, go to Rear of Vehicle Low .
    • The air compressor runs excessively. Check for a disconnected or damaged air tube or a damaged strut. If OK, go to Rear of Vehicle Low .

2

Add a 300 lb. load to the luggage compartment.

After a 17-27 second delay, the air compressor runs and the rear of the vehicle rises to the correct trim height. Refer to Trim Height in Suspension General Diagnostics.

    • The air compressor cycles on and off frequently. If no air leaks are present, go to Rear of Vehicle Low .
    • The air compressor runs excessively. Check for a disconnected or damaged air tube or a damaged strut. If OK, go to Rear of Vehicle Low ..

3

Turn the ignition switch to the OFF position.

Remove the load from the luggage compartment.

After a 17-27 second delay, a hiss of escaping air may be heard, and the rear of the vehicle lowers to the correct trim height. Refer to Trim Height in Suspension General Diagnostics.

The rear of the vehicle remains high. Refer to Rear of Vehicle High .