Rear suspension (Height sensors): Description and operation

Height sensors

1 Spacer 2 Link end 3 Link 4 Link end 5 Arm 6 Sensor body

Two height sensors are located on the outside of each chassis longitudinal forward of the rear axle. Each sensor body is attached to a fabricated bracket and secured with two screws. The sensor is attached to the top of each radius arm by an arm, a link and two link ends. The link ends allow articulation of the arm to allow for suspension travel. The lower link arm is attached to a lug of the top of the radius arm and is secured with a bolt and locknut.

The sensor body and arm are manufactured from moulded nylon. The two link ends are made from natural rubber and the link is made from mild steel. The rubber link ends allow flexibility of the arm and resistance to damage.

Each sensor is connected to the main chassis harness by a multiplug. The three pin multiplug provides an earth, a 5 V supply voltage and an output signal voltage to the SLABS ECU.

Each sensor operates on the Hall effect principle. A magnet is attached to the shaft and rotates with movement of the arm. The magnetic flux generated acts on a Hall effect sensor and depending on its position varies the current across the sensor. This current is measured and amplified and passed to the SLABS ECU as a linear output voltage signal, which varies depending on the angular position of the sensor. The signal information is processed and the ECU can determine the vehicle height.

When the sensors are replaced or removed for any reason, a calibration procedure is required to recalibrate the sensors and the SLABS ECU. The calibration procedure requires the use of TestBook and calibration blocks to set the axle to chassis height to a known value.

If faults occur with the height sensors, fault codes are stored in the SLABS ECU. The current and past fault codes can be retrieved with TestBook.