Height Sensor, Suspension

Fig 1: Identifying Height Sensor

Courtesy of VOLVO CARS CORPORATION

A height sensor is connected to the suspension for each wheel via a link system. The height sensor measures the wheel's vertical position in relation to the body. The sensors are supplied with 5 V by the suspension module (SUM). When the vehicle is stationary, the output signal from the sensor is approximately 2.5 V. When there is vertical movement the signal will oscillate around this value; the greater the movement the greater the deviation. The voltage can oscillate between 0.5-4.5 V.

NOTE: The values move in different directions on the left and right-hand sides. Upwards body movement results in increased voltage on the left-hand side and a voltage drop on the right-hand side.

Information about the wheel's position and movement is used together with the signals from the acceleration sensors on the body by the control module to calculate damping in each shock absorber.

The height sensors can be diagnosed by the Suspension module (SUM) and must be calibrated after replacement.