See also:

High outside temperatures
If DEF heats up to over 122 °F (50 °C ) for extended periods, e.g. as a result of direct sunlight on the DEF reservoir, DEF can decompose. Ammonia vapors develop as a result. WARNING When o ...

Activating/deactivating airrecirculation mode
You can deactivate the flow of fresh air if unpleasant odors are entering the vehicle from outside. The air already inside the vehicle will then be recirculated. The operation of air-recirculati ...

Notes on technical data
The data stated here specifically refers to a vehicle with standard equipment. Consult an authorized Mercedes-Benz Center for the data for all vehicle variants and trim levels. ...