Automatic Level Control

Sensor 

The following applies to vehicles without Four-C (Continuously Controlled Chassis Concept) 

An inductive position sensor reads off the angle between the bodywork and the left rear control arm. The angle is a measurement of how much the vehicle is leaning (chassis height) and is dependent on weight distribution.

• The sensor is mounted differently in FWD to AWD
• The rear electronic module (REM) reads an analog signal (0.5-4.5 V) from the position sensor and converts it to an angle value (±35°), which is transmitted to the central electronic module (CEM)
• Fully laden vehicles give a signal of 0.5 V which corresponds to minus 35°.
• The central electronic module (CEM) controls the motors for the headlamp range adjustment (PWM signal) and sets the headlamps vertically.

The following applies to vehicles with Four-C 

Two sensors read off the angle between the bodywork and the left and right rear control arms. The angle is a measurement of how much the vehicle is leaning (chassis height) and is dependent on weight distribution.

The sensors are mounted differently in FWD to AWD.

The suspension module (SUM) reads the signals from the sensors and converts them to an angle value. The value is transmitted via the control area network (CAN) to the central electronic module (CEM). The central electronic module (CEM) uses this information to control the motors for headlamp range adjustment.

Level control 

Controlled at speeds below 4 km/h 

When the ignition is switched on, the position sensor is read off and the headlamp range adjustment motors set the headlamps.

Controlled at speeds above 4 km/h 

At greater angle changes during driving the headlamps are controlled. Control is dependent on the time for the system not to react to short term changes such as uneven road surfaces etc.

Calibration 

The position sensor must be calibrated after work on the rear suspension. Carry out calibration according to tab DIAGNOSTICS/VEHICLE COMMUNICATION, rear electronic module (REM).