Vehicle Dynamic Suspension (G2298393): Description: Accelerometers
Accelerometer - Front Suspension
Accelerometer - Rear Suspension
There are 4 accelerometers used in the Adaptive Damping (AD) system. Each accelerometer is attached to the related wheel knuckle. The front accelerometer is secured directly to the front wheel knuckle with a bolt. The rear accelerometer is attached to a mounting bracket with a nut. The mounting bracket is secured to the rear wheel knuckle with a bolt.
The accelerometers measure acceleration in the vertical plane and output a corresponding analogue signal to the Chassis Control Module (CHCM). The algorithms in the CHCM use these inputs to calculate the wheel motions and to modulate the valve currents accordingly.
Each accelerometer is connected to the CHCM via 3 wires, which provide 5V power supply, ground and signal return connections.
The sensing element comprises a single parallel plate capacitor, a plate of which moves relative to the other dependant on the force (acceleration) applied. This causes the capacitance to change as a function of applied acceleration. This capacitance is compared with a fixed reference capacitor in a bridge circuit and the signal is processed by means of a dedicated integrated circuit. The processed signal generates an output voltage that varies as a function of applied acceleration. The sensors output a signal voltage of approximately 0.15 V/g ± 0.05 V/g. When the vehicle is stationary, each accelerometer outputs approximately 2V.
If an accelerometer is replaced the accelerometer offsets need to be updated using the Jaguar Land Rover (JLR) approved diagnostic equipment.