See also:

Important safety notes
ATTENTION ASSIST helps you during long, monotonous journeys such as on freeways and interstate highways. It is active in the range between 50 mph (80 km/h) and 112 mph (180 km/h). If ATTENTIO ...

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 ...

Storing the current speed or calling up the last stored speed
WARNING The set speed stored in memory should only be set again if prevailing road conditions and legal speed limits permit. Possible acceleration or deceleration differences arising from ...