SMU - New Air Suspension Pressurization Procedure

This bulletin is being issued to add the Air Suspension Pressurization Procedure to the Air Suspension sub-section of the Service Manual. Please include the following information in the Service Manual.

The following information has been added to SI. If you are using a paper version of this Service Manual, please make a reference to this bulletin on the affected page.

The following procedure needs to be followed whenever the Air Suspension Depressurization Procedure (SI Document ID #858084) is used.

Important: Any time the air suspension system has been depressurized, it is necessary to follow the steps below to avoid air spring damage upon lowering the vehicle and adding weight to the rear suspension components.

1. While the vehicle is raised, ensure that the lower end of the air springs are completely engaged in the spring supports on the axle housing.
2. Lower the vehicle but do not allow the vehicles tires to contact the ground.
3. Turn the ignition ON, with the engine OFF.
4. Install a scan tool.
5. With the scan tool in hand, raise the vehicle.
6. With the scan tool select Special Functions.
7. Select Compressor Test.
8. Press the ON soft key and visually observe the springs as their air pressures inflate.
9. When the air spring inflation pressures have reached a pressure where there are no visible wrinkles, or folds in the air springs, press the OFF soft key. This function will also stop after 90 seconds.
10. Press the Exit key.
11. Lower the vehicle.
12. Cycle the ignition OFF, then back ON, with the engine ON to allow the air suspension system to regain the desired rear suspension position.