Component Tests and General Diagnostics

Vehicle Dynamic Suspension

Component Test


Air Suspension Relay

Refer to Air Suspension Relay for component testing.


Pneumatic Test

This test verifies that the air lines are connected and that they are not restricted. It also verifies that the air compressor, air compressor vent solenoid and air spring solenoid valves are functioning correctly. Verify that the following conditions are met before running the Pneumatic Test.

- All doors, the liftgate and the liftgate glass must be closed.
- Transmission must be in PARK.
- The ignition switch is in the RUN position.
- The air suspension service switch must be in the ON position.
- Battery voltage is greater than 11 volts for the duration of the test.

1. Fulfill the pre-test conditions.

2. Follow the directions on the scan tool to carry out the Pneumatic Test.


Trim Height Test (or Accurate Trim Test)

NOTE: The trim height test is used to verify trim height only. If trim height needs to be adjusted, refer to Ride Height Adjustments Ride Height Adjustments.

The trim height test is used to make the vehicle level to within 2 mm (0.08 in) of the calibrated trim height. Accurate trim test should be run before setting vehicle alignment.

- All doors, the liftgate and the liftgate glass must be closed.
- Transmission must be in PARK.
- The ignition switch is in the RUN position.
- The air suspension service switch must be in the ON position.
- Battery voltage is greater than 11 volts for the duration of the test.

1. Fulfill the pre-test conditions.

2. Install a battery charger for the Trim Height Test to prevent battery drain.

3. Follow the directions on the scan tool to carry out the Trim Height Test.