See also:

Text messages
Text messages at the upper edge of the Control Display explain the meaning of the displayed indicator and warning lamps. ...

Tone control
You can alter various tone settings, e.g. treble and bass or the speed-dependent volume increase. The tone settings are applied to all audio sources. The settings are stored for the remote control ...

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