Distributed functions

The Integrated Chassis Management (ICM) is the higher-level control unit in which the setpoint values of the Integral Active Steering are calculated. The ICM uses the current driving status and steering angle of the driver to calculate the setpoint values for the variable steering box ratio and yaw-rate control. Once these values have been prioritized, the ICM provides resulting setpoint values for the AL and HSR control units. This is a specified angle that is set at the front wheels and rear wheels. Both control units receive the setpoint value and trigger the actuator in such a way that the setpoint value is implemented correctly.

Both control units are thus exclusively control units for actuators.

The control units are connected on the FlexRay. The FlexRay is routed through the AL control unit to the HSR control unit.

Servotronic Both the base steering and Integral Active Steering have Servotronic. The speed-dependent steering servo is implemented by the Servotronic valve on the steering box. The Servotronic valve is always controlled by the ICM control unit. This means that the ICM control unit also contains the logic of the Servotronic function.

The ICM control unit also activates the ECO valve. This valve enables electronic adjustment of the volumetric flow of the power steering pump.

Notice! Other functional descriptions are important. 

For details of the driving stability control systems, consult the functional descriptions in the diagnosis system.