GM Service Manual Online
For 1990-2009 cars only

This procedure noted below should be performed after compressor assembly, air suspension control module, or suspension position sensor replacement. Uneven suspension position can also be corrected by performing this procedure.

Tools Required

CH-47816 Suspension Position Calibration Blocks

Important: Before proceeding with the steps below, ensure:

   • There are no stored diagnostic trouble codes stored in the ASCM.
   • The vehicle is on level ground.
   • There are no occupants in the vehicle.
   • The tire pressures are at the recommended kPa/psi.
   • All vehicle doors are closed.

  1. Raise the vehicle on a hoist.
  2. Install the CH-47816 on to the LR and RR jounce bumper mounting cups.
  3. Lower the vehicle off the hoist.
  4. Depressurize the air suspension system in order to allow the full rear weight of the vehicle to rest on the blocks and rear axle. Refer to Air Suspension Depressurization .
  5. Start the engine.
  6. Install a scan tool.
  7. With the scan tool select Chassis.
  8. Select Air Suspension Control Module.
  9. Select Special Functions.
  10. Select Suspension Position Calibration and press the Enter key.
  11. Press the SELECT soft key to complete the calibration procedure.
  12. Press the Exit key.
  13. Pressurize the air suspension system until the rear weight of the vehicle is lifted off of the blocks. Refer to Air Suspension Pressurization .
  14. Remove the CH-47816 .
  15. Ensure all vehicle doors are closed. Cycle the ignition switch OFF then start and run the engine for 2 minutes to allow the vehicle to level at the designed ride height.
  16. Ensure all vehicle doors are closed. Verify the air suspension system is functioning properly by pressing the extended ride height (ERH) switch once to raise the vehicle to the extended ride height and press the switch again to level the vehicle back to the designed ride height.