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 opening the filler cap of the DEF tank
ammonia gas vapors may escape. Refill DEF
in a well ventilated area only. Ammonia gas
vapors have a pungent odor and are
particularly irritating for your skin, mucous
membranes, and eyes. Inhaling ammonia gas
vapors will cause burning eyes, nose, and
throat, as well as coughing and watering eyes.
See also:
Important safety notes
WARNING
The PARKTRONIC is a supplemental system.
It is not intended to, nor does it replace, the
need for extreme care. The responsibility
during parking and other critical maneuvers
...
Cleaning the steering wheel and gear orselector lever
► Thoroughly wipe with a damp cloth or
use
leather care agents that have been
recommended and approved by Mercedes-
Benz. ...
Automatic engine start
The engine is started automatically if you:
- release the brake pedal when HOLD is not
activated and the transmission is in
position D or N
- shift the transmission to position R
...