See also:

Automatic deactivation during forward travel
The system switches off when a certain driving distance or speed is exceeded. Switch the system back on if necessary. ...

Malfunction
A message is displayed in the instrument cluster. HDC is not available, e.g., due to elevated brake temperatures. ...

USB audio interface/mobile phone audio interface
At a glance It is possible to connect external audio devices. They can be operated via iDrive. The sound is output on the vehicle loudspeakers Connectors for external devices ▷ Connection ...