See also:

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

Switching off automatically
The system switches off and the LED goes out: After approx. 160 ft/50 m when driving forward. Above approx. 22 mph/36 km/h when driving forward. Switch on the system again if necessary. ...

Software Update
The vehicle supports various external devices depending on the current software version. With a software update, the vehicle can support new cell phones or new external device, for example. ...