GM Service Manual Online
For 1990-2009 cars only

Action

Normal Results

Important: For vehicles with accessory air inflator.

Depress the automatic level control inflator air switch ON.

    • The automatic level control air compressor motor turns on and runs continuously for up to 10 minutes before automatically shutting off.
    • The rear of the vehicle should not rise.

Important: For vehicles with accessory air inflator.

Depress the automatic level control inflator air switch OFF.

The automatic level control air compressor motor turns off.

With no load in the vehicle, turn the ignition switch to RUN.

  1. After a 40 second delay, the automatic level control air compressor runs for 3-5 seconds.
  2. The system then exhausts down to a minimum pressure of 55-97 kPa (8-14 psi).

Turn the vehicle ignition switch back OFF and add a 250-300 lb load to the rear of the passenger compartment.

  1. During (or 7-14 seconds after) the loading of the vehicle, the system exhausts for 1 second, then the automatic level control air compressor motor turns on.
  2. Within 1 minute, the rear of the vehicle rises to a predetermined height and the automatic level control air compressor turns OFF.

Remove the load from the passenger compartment.

    • During (or 7-14 seconds after) the unloading of the vehicle, the system exhausts.
    • The rear of the vehicle lowers to the original, unloaded height.
    • The system retains a minimum pressure of 55-97 kPa (8-14 psi).