See also:

Functional readiness of the airbag system
When the ignition is switch on, the warning lamp in the instrument cluster lights up briefly and thereby indicates the operational readiness of the entire airbag system and the belt tension ...

Activating HDC
Press the button; the LED above the button lights up. ...

General information
The following functions are available: ▷ Use of a mobile phone as a telephone. ▷ Use of a mobile phone as an additional telephone. ▷ Use of a mobile phone as an audio source. ...