Compressor Assemblies

WARNING: This page is about a different car, the 2007 Hummer H2. However, it is still accessible from the selected car via links, so may be relevant.

The air suspension system consists of 2 compressor assemblies. Both compressors run simultaneously and are controlled by one relay. One compressor has the exhaust valve mounted on its cylinder head. Each compressor has its own thermal limit switch. The compressors are a positive displacement air pump, powered by a 12-volt DC permanent magnet motor. A thermal limit switch is included to protect each compressor from being damaged as a result of each compressor running so long that it becomes overheated, which may be caused by excessive use of the inflator or a faulty air suspension relay. The thermal limit switch is normally closed and provides a ground signal to the air suspension module. If there is an overtemperature condition the thermal limit switch will open and signals the air suspension module to deactivate the compressor relay. The compressors will stop running and a DTC will set. As long as both compressors have not been damaged, the thermal limit switch will close, clearing the DTC, as the over temperature condition returns to normal leading to both compressors operating under normal conditions. Intake air for the compressors is drawn through an intake filter and line that is attached to the fuel filler pipe in the left rear wheel area. The air compressor assemblies are mounted to a bracket that is located under the rear center of the vehicle. The compressor air dryer is mounted next to the air compressors. It contains a moisture absorbing chemical that dries the compressed air before it is delivered to the rear air springs. Moisture is removed from the dryer and returned to the atmosphere when air is exhausted from the air springs during vehicle lowering.