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:
Engine emergency off
If the engine cannot be switched off as
described, observe the following procedure:
Take the fuse allocation chart out of the
vehicle document wallet.
Search for “Emergency engine shutdown”
...
General notes
WARNING
All categories of messages contain important information which should be taken
note of and,
where a malfunction is indicated, addressed as soon as possible at an authorized
Mercedes-B ...
Setting a speed
WARNING
Keep in mind that it may take a brief moment
until the vehicle has made the necessary
adjustments.
Increase or decrease the set vehicle speed to
a value that the prevailing road co ...