See also:

Capacities
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Deactivating HDC
Press the button again and the LED goes out. HDC is automatically deactivated above approx. 37 mph/60 km/h. ...

Servotronic
The conceptThe Servotronic varies the steering force required to turn the wheels relative to the vehicle speed. At low speeds, the steering force is strongly assisted, i.e. less force is needed f ...