The air suspension system fully suspends the rear of the vehicle and maintains a desired rear suspension position during all types of hauling and loading conditions. The primary mission of the air suspension system is the following for the rear suspension under loaded and unloaded conditions:

The air suspension system consists of the following items:

When the vehicle is unloaded, the rear suspension is at a desired position, which is monitored by the ASCM using its LR and RR position sensor signal voltage inputs. As weight is added to the rear of the vehicle, the rear suspension position changes thus changing the position sensor's signal voltage inputs. If the ASCM detects a steady constant change in position sensor signal voltage for at least 3 seconds, it responds by commanding on the compressor relay causing the air compressor to activate. Once the air compressor is activated, the ACSM opens the LR and RR air spring control valves, causing the rear air spring pressures to inflate. This inflation raises the rear of the vehicle to regain the desired suspension position. When weight is removed from the rear of the vehicle, the ASCM responds by commanding ON the exhaust valve and LR and RR air spring control valves, causing the air spring pressures to deflate. This deflation lowers the rear of the vehicle to regain the desired suspension position. The ASCM also monitors the engine run status from the ECM via the serial data circuit and will not allow compressor activity unless the engine is running to avoid battery run down.

The compressor is a positive displacement air pump driven by a 12-volt DC permanent magnet motor. The compressor draws filtered air through an intake line attached to the chassis rail which is then run through a dryer containing a moisture-absorbing chemical that dries the air before it is sent to the air springs. The moisture is removed from the dryer during exhaust events, or when the system is depressurized. If the compressor is exposed to high thermal conditions due to excessive run time, the ASCM will command the compressor relay OFF to protect the compressors from thermal damage

The air compressor is controlled by the air suspension control module by the use of a relay. The relay and wiring are protected with a 60-amp fuse. The air suspension control module will only activate the compressor relay when the engine is running.

The air suspension control module (ASCM) has the ability to detect malfunctions within the air suspension system. Any malfunction detected will cause the driver information center (DIC) to display the SERVICE SUSPENSION SYSTEM message.

The air springs are mounted in the frame in the same location were the coil spring is mounted for a vehicle without air suspension. Support pieces are affixed to the control arm for the air springs.