GM Service Manual Online
For 1990-2009 cars only

Review the system operation in order to familiarize yourself with the system functions. Refer to Automatic Level Control Description and Operation .

Visual/Physical Inspection

    • Inspect for aftermarket devices which could affect the operation of the automatic level control suspension. Refer to Checking Aftermarket Accessories in Wiring Systems.
    • Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
    • Inspect for binding or damaged shock absorbers.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

    •  Automatic Level Control Air Compressor Performance Test
    •  Automatic Level Control System Leak Test
    •  Rear of Vehicle High
    •  Rear of Vehicle Low