See also:

Applying
The lever automatically engages after being pulled up. ...

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

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 ...