Expedition 2WD V8-281 4.6L VIN W EFI (1997)
Ride Height Sensor: Description and Operation
Four Wheel Air Suspension
Two height sensors are mounted on the vehicle. The sensors send 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
sensors have a useable range of 80 mm (3 in) compared to total suspension travel of 200-250 mm (8-10 in) at the wheel. Therefore, the sensors are
mounted to the suspension at a point where full suspension travel at the wheel is relative to 80 mm (3 in) of travel at the height sensor. The front height
sensor upper socket is attached to the bracket to the frame at the upper control arm mounting area and the lower height sensor socket is attached to the
upper control arm bracket. The rear height sensor is attached between the No. 5 frame crossmember (upper socket) and the panhard rod (lower socket).
Replace a sensor as a unit.
When the height sensor gets shorter the vehicle is lowered and this will cause the air compressor to turn on and pump compressed air to the system.
When the sensor gets longer the vehicle is being raised and this will cause the air to be vented from the system to lower the vehicle to its trim height
level.
