GM Service Manual Online
For 1990-2009 cars only

Diagnostic System Check - Automatic Level Control With Inflator

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. The presence of DTCs

  2. The symptom list in Symptoms will determine the correct diagnostic procedure to use.

Step

Action

Yes

No

Schematic Reference: Automatic Level Control Schematics

1

Turn ON the ignition, with the engine OFF.

Press the accessory inflator switch for 3 seconds to enter diagnostic mode.

After 200 seconds does the LED flash code 12?

Go to Step 2

Go to Step 4

2

Press and release the accessory inflator switch.

Does the LED in the Switch stop flashing?

Go to Step 3

--

3

Cycle the ignition switch from ON to OFF.

Did you complete the procedure?

System OK

--

4

Does the LED in the accessory inflator switch flash other codes?

Go to Diagnostic Trouble Code (DTC) List

Go to Symptoms - Automatic Level Control

Diagnostic System Check - Automatic Level Control without inflator

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. The presence of damage to any components of the system.

Step

Action

Yes

No

Schematic Reference: Automatic Level Control Schematics

1

    • Check airlines for blockage or disconnection.
    • Check for damage or kinks in airlines.
    • Check for damage to shock absorbers.
    • Check for damage to air compressor assembly.

Did you find and correct the condition?

System OK

Go to Symptoms - Automatic Level Control