Expedition 4WD V8-4.6L SOHC VIN 6 (1997)
Ride Height Sensor: Description and Operation
Rear Air Suspension
When the height sensor gets shorter the rear of the vehicle is lowered and this will cause the air compressor to turn on and pump compressed air to the air
springs. When the sensor gets longer the rear of the vehicle is being raised and this will cause the air to be vented from the air springs to lower the
vehicle back to its trim height level.
One height sensor is mounted on the vehicle. The sensor sends a voltage signal to the control module. The output ranges from approximately 4.75 volts
at minimum height (when the vehicle is low or in full jounce), to 0.25 volts at maximum height (when the vehicle is high or in full rebound). The sensor
has a useable range of 80 mm (3 in) compared to total suspension travel of 200-250 mm (8 to 10 in) at the wheel. Therefore, the sensor is mounted to
the suspension at a point where full rear suspension travel at the wheel is relative to 80 mm of travel at the height sensor. The rear height sensor is
attached between the No. 5 frame crossmember (upper socket) and the panhard rod (lower socket). Replace the sensor as a unit.
