Suspension: Service and Repair

The content of this article reflects the changes identified in TSB 05-03-99-001.

A new essential tool has been developed and shipped to all North American dealers for the H2 air suspension system. These Suspension Position Calibration Blocks, CH-47816, are to be used during the suspension position calibration procedure.

Suspension Position Calibration

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.

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.


1. Raise the vehicle on a hoist.

Suspension Position Calibration Blocks CH-47816:

2. Install the suspension position calibration blocks on 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.
5. Turn ON the ignition, with the engine OFF.
6. Install a scan tool.
7. With the scan tool select Chassis.
8. Select Air Suspension.
9. Select Special Functions.
10. Select Trim Height Calibration and press the Enter key. The scan tool will flash Calibration In Progress, then display Calibration Complete.
11. Press the Exit key.
12. Pressurize the air suspension system until the rear weight of the vehicle is lifted off the blocks.
13. Remove the calibration blocks.
14. Cycle the ignition switch Off then start and run the engine for 2 minutes. Verify the Air Suspension system is functioning properly.