Inputs and Outputs

The Air Suspension System maintains the vehicle's front and rear end height within predetermined limits when passengers enter or exit the vehicle and objects are placed in or removed from the trunk.

Vehicles equipped with the Air Suspension System do not have conventional coil springs placed between the suspension control arms and the frame. Instead, the vehicles are equipped with inflatable air springs that are inflated or deflated by an Air Suspension Compressor/Vent Solenoid assembly, which is controlled by the Air Suspension Control Module.

MODULE INPUTS

Air Suspension Switch

The Air Suspension Switch turns the system on and off during repair and/or diagnostic procedures.

Door Jamb Switches

With any door open (or ajar), battery voltage is present on circuit 24 (DB/O) at the Air Suspension Control Module. With this signal present, the Module will not lower the vehicle.

This prevents an open door from being lowered onto a curb or other object.

Linear Height Sensors

Three linear Height Sensors are used to determine whether or not vehicle height is within predetermined limits. The Air Suspension Control Module supplies power and ground to each Sensor and then monitors the signals it gets back on the "logic" circuits. Each Height Sensor can indicate only three conditions: vehicle at trim height, vehicle above trim height and vehicle below trim height.

Stop Lamp Switch

The Stop Lamp Switch provides a brake on/off input to the Air Suspension Control Module. With the brakes applied and a door open, the Module may raise (but not lower) the front or rear of the vehicle. With the brakes applied and all doors closed, the Module will not raise or lower the front or rear of the vehicle.

MODULE OUTPUTS

Air Spring Solenoids

Each air spring assembly has a replaceable Air Spring Solenoid. This Solenoid operates a valve that blocks air from entering or leaving air spring assembly. The Air Spring Solenoid windings are grounded by the Air Suspension Control Module when air must be added or removed from the air springs.

Vent Solenoid

The Vent Solenoid is located inside the Air Suspension Compressor. When energized, the Solenoid operates a valve that allows air released from the air springs to be vented to the atmosphere.

Compressor Relay

Voltage is present at the Compressor Relay coil and contacts at all times. The Compressor Relay coil ground circuit is controlled by the Air Suspension Control Module. When the Module grounds the coil, the Relay contacts close, and power flows to the Air Suspension Compressor Motor.

Warning Indicator

When the Air Suspension Control Module detects a system fault, it grounds circuit 419 (DG/LG) to the Overhead Warning Indicator Display and the CHECK SUSPENSION Indicator turns on. Also, the Indicator turns on when the Air Suspension Switch is turned OFF.