Air Suspension

Suspension Position Calibration

After air suspension control module (ASCM), or suspension position sensor replacement, or if the vehicle exhibits an uneven rear suspension position, the following calibration procedure must be performed.

Important: Before proceeding with the procedure below, ensure:

* The vehicle is parked on level ground.

* There are no stored DTCs in the ASCM.

* If the vehicle has been lowered from a hoist, roll the vehicle back and forth 2 full tire revolutions to ensure the suspension is not bound.

* All tire pressures are set to the recommended kPa/psi.

* There are no occupants in the vehicle.

* There are no heavy objects stored in the luggage compartment.

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. Using 2 adjustable lifting devices, support the rear of the vehicle at the lifting points forward of the rear wheel arches.
4. Depressurize the air suspension system, allowing the weight of the vehicle to rest on the lifting devices. Refer to Air Suspension Depressurization.
5. Measuring from the wheel center to the wheel arch, ensure a 46 cm (18.1 in) distance between the 2 points for both left and right sides. Adjust the lifting devices as needed.
6. With the scan tool select Suspension, and then Air Suspension.
7. Select Special Functions, Air Suspension Control Module.
8. Select Suspension Position Calibration and press the Set key.
9. Remove the lifting devices.
10. Cycle the ignition OFF, then start the engine and allow to run for 1 minute. Verify the air suspension system is functioning properly.
11. If additional adjustments are required for slight variation in the trim height after completing the Suspension Position Calibration, use the Suspension Calibration Adjustment procedure under Special Functions and follow the Tech2 on-screen instructions to adjust each rear wheel to the correct trim height. The Suspension Calibration Adjustment will increase or decrease the left and/or right rear wheel center to wheel arch measurement from 0.64 cm (0.25 in) to as much as 2.54 cm (1 in) to correct the variation in the trim height.