See also:

Emergency Tensioning Devices, belt force limiters
The front seat belts and the outer seat belts in the rear are equipped with ETDs and seat belt force limiters. The ETDs tighten the seat belts in an accident, pulling them close against the body. ...

Important safety notes
WARNING Severe conditions (e.g. strong air pollution) may require replacement of the filter before its scheduled replacement interval. A clogged filter will reduce the air volume to the interi ...

Problems with the seat ventilation
The seat ventilation 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 ...