Steering Systems - Functional Description: Servotronic: Function

The system regulates the power-assisted steering on a speed-dependent basis. The Servotronic valve variably throttles the flow of hydraulic oil in the power steering. The degree of throttling depends on the current used to activate the valve.

The characteristic curve for the Servotronic valve specifies the current depending on the speed.

The characteristic curve is described by reference points, whereby the speed and current are coded for each reference point. The Servotronic only activates the Servotronic valve if terminal 15 is on and the engine is running. As long as there is no speed signal at engine startup, the maximum possible steering power assistance is set. When the correct traveling speed is received, the specified value is taken from the electrical characteristic curve.