See also:

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

Controls
1 Change entertainment sources 2 Change station/track 3 Programmable memory buttons 4 Volume, on/off 5 Change wave band ...

System limits
Check the traffic situation as well PDC cannot serve as a substitute for the driver's personal judgment of the traffic situation. Check the traffic situation around the vehicle with your own ey ...