DEF
Important safety notes
Comply with the important safety notes for service products when handling DEF .
DEF is a water-soluble fluid for the exhaust gas aftertreatment of diesel engines. It is: • not poisonous • colorless and odorless • not flammable When you open the DEF container, small amounts of ammonia vapor may be released
Ammonia vapors have a pungent odor and are particularly irritating to the skin, to mucous membranes and to the eyes. You may experience a burning sensation in your eyes, nose and throat. Coughing and watering of the eyes are possible.
Do not inhale ammonia vapors. Fill the DEF tank only in well-ventilated areas.
Low outside temperatures
DEF freezes at a temperature of
approximately 12 
(-11
). The vehicle is
delivered from the factory equipped with a
DEF preheating system. Winter operation can
thus be guaranteed even at temperatures
below 12 
(-11
).
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.
Purity
Impurities in DEF (e.g. due to other
service products, cleaning agents or dust)
lead to:
• increased emission values
• damage to the catalytic converter
• engine damage
• malfunctions in the BlueTEC exhaust gas
aftertreatment system
Filling capacities
See also:
Unlocking and opening doors from
the inside
If the vehicle has previously been locked with
the SmartKey, opening a door from the inside
will trigger the anti-theft alarm system.
Switch off the alarm .
Only open the door when the traffic ...
Flat tire
You can find information on what to do in the event of a flat tire in the
"Breakdown assistance" section .
Information on driving with MOExtended tires in the event of a flat tire ...
Mechanical key
General notes
If the vehicle can no longer be unlocked with
the SmartKey, use the mechanical key.
If you use the mechanical key to unlock and
open the driver's door or the rear door, the
anti-t ...