DESCRIPTION
Note. Electronic suspension system may also be referred to as the load levelling control system or vehicle dynamic suspension system.
Two optional computer controlled air suspension systems are available. Rear Air Suspension (RAS) system, available only on 2WD models, replaces conventional steel coil rear springs with 2 air springs providing low spring rates for improved ride and automatic rear load leveling. Air springs are mounted on the rear axle spring seats and to the frame upper spring seats, much like conventional steel coil springs.
Four Wheel Air Suspension (4WAS) system is available only on 4WD models. To control ride height at all 4 corners of vehicle, RAS system is combined with front air shock absorbers. Other components include air compressor assembly, air lines, solenoids, height sensor(s) and Generic Control Module (GEM). On both systems, ride height is determined by GEM in response to load, road and driving condition inputs received from 2 suspension mounted height sensors (1 sensor on RAS system), Vehicle Speed Sensor (VSS) and Throttle Position Sensor (TPS).
OPERATION
Both air suspension systems are operational with ignition switch in RUN position and have limited operation for 40 minutes after ignition is turned off. The air suspension switch, located under glove box in right kick panel, must be turned off when vehicle is being hoisted, towed or jump-started.
Air suspension warning light is located in instrument cluster. Warning light stays on when air suspension is turned off or a system malfunction is detected.
Air required for leveling vehicle is distributed from air compressor to front and rear fill solenoids through nylon air lines. Front air system can be pneumatically separated from side to side by control module activation of front gate solenoid. This separation provides vehicle stability during roll conditions.
For safety during loading and unloading, vehicle height is memorized and maintained when any door is opened. Vehicle will return to commanded height when doors are closed or vehicle speed exceeds 10 MPH.