See also:

Malfunction
A Check Control message is displayed. On the Control Display, the areas in front of and behind the vehicle are shaded. PDC has failed. Have the system checked. To ensure full operability: ...

Environmental conditions
Say the commands, numbers, and letters smoothly and with normal volume, emphasis, and speed. Always say commands in the language of the system. The language for the mobile phone voice ...

Switch off the engine during longer stops
Switch off the engine during longer stops, e.g., at traffic lights, railroad crossings or in traffic congestion. Fuel savings are achieved after the vehicle is switched off for only approx. 4 s ...