See also:

Functional readiness of the airbagsystem
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 tensioner. ...

Audio playback
Selecting the track using the button Press the button repeatedly until the desired track is played. Selecting the track using the iDrive Audio CDs Select the desired track to begin playback. ...

Switching on/off manually
Switching on/off manually Press the button. ▷ On: the LED lights up. ▷ Off: the LED goes out. ...