DeVille V8-4.6L VIN Y (1998)
Ride Height Sensor: Description and Operation
GENERAL DESCRIPTION
Height Sensor
IMPORTANT: The height sensor does not apply to vehicle equipped with Road Sensing Suspension.
The solid-state height sensor detects height changes at the rear of the vehicle and, in turn, controls the functions of the compressor and exhaust
solenoid. To prevent energizing the compressor relay or exhaust solenoid during normal ride motions, the sensor circuit provides a fixed delay before
ground is completed to either circuit. In addition, the sensor limits compressor run time and exhaust solenoid energized time to a range of 4.5 to 7.5
minutes. This prevents continuous compressor operation in case of a severe system leak or continuous exhaust solenoid operation. The timer circuit is
reset whenever the ignition is cycled OFF and ON, or the sensor exhaust or compress output signal changes. The sensor is mounted on the left front
side of the rear suspension support assembly. The sensor actuation arm is attached to the upper left control arm by a link.
Position Sensor
IMPORTANT: The height sensor does not apply to vehicle equipped with Road Sensing Suspension.
The two position sensors that are utilized by the Automatic Level Control (ALC) system are mounted on the body, one sensor over each upper control
arm of the rear suspension. Each rear position sensor has a link that is connected to corresponding rear suspension upper control arm. The
Continuously Variable Road Sensing Suspension (CVRSS) control module provides supply voltage (8 volts) and ground to the position sensors. The
position sensors then supply an analog output voltage of 0.35 to 4.75 volts back to the CVRSS control module. The amount of voltage (0.35 to 4.75)
is dictated by the vertical height of the rear of the vehicle.
