See also:

Problems with the seat heating
The seat heating has switched off prematurely or cannot be switched on. The vehicle's electrical system voltage is too low because too many electrical consumers are switched on. - Switch off ...

Displays and controls
  ...

Vehicle remote opening
If you have unintentionally locked your vehicle (e.g. the SmartKey is still in the vehicle) and a replacement SmartKey is not available, the vehicle can be opened by a Mercedes-Benz Customer Assis ...