See also:

Additives
Only use DEF in accordance with ISO 22241. Do not use additives with DEF and do not dilute DEF with water. This may destroy the BlueTEC exhaust gas aftertreatment system. ...

Winter driving
Important safety notes WARNING   If the vehicle becomes trapped in snow, ensure that snow is kept away from the exhaust pipe and from around the vehicle as long as the engine is running ...

Switching on/off
The three red indicator lamps in the button indicate the heating level you have selected. If the battery voltage is too low, the seat heating may switch off. One or more of the indicator lamp ...