See also:

Switching on automatically
Select transmission position R with the engine running. ...

The concept
The system is functional at speeds beginning at approx. 20 mph/30 km/h. It maintains the speed that was set using the control elements on the steering wheel. The system brakes on downhill gradie ...

Automatic deactivation during forward travel
The system switches off when a certain driving distance or speed is exceeded. Switch the system back on if necessary. ...