When opening the DEF tank filler cap at high
outside temperatures, ammonia vapors may
escape.
Ammonia vapors have a pungent smell and pri-
marily cause irritation of the:
Rskin
Rmucous membranes
Reyes
You may experience a burning sensation in your
eyes, nose and throat, as well as coughing and
watering of the eyes.
Do not inhale ammonia vapors. Avoid contact
with DEF.
Do not allow DEF to come into direct contact
with your skin; it is hazardous to your health.
Rinse any affected areas off with plenty of clean water. Consult a doctor if necessary.
If DEF heats up, e.g. in direct sunlight, in the DEF
supply reservoir for some time to over 122 ‡
(50 †), ammonia vapor will develop.
To conform to emission regulations, you must
operate the vehicle with DEF and refill the supply
regularly. The engine management recognizes
attempts to operate the vehicle without DEF,
with thinned DEF or with another reducing
agent. After previous warning messages, the
engine management then prevents a further
engine start.
When the number of remaining engine starts is 0
the engine management prevents the vehicle
from being driven at a speed exceeding 5 mph
(8 km/h). The multifunction display shows the
Idle Mode
message.
DEF consumption
DEF consumption depends on operational and
driving conditions and it is not necessary to wait
until the next scheduled service to replenish the
fluid. Fluid should be added regularly to the DEF
supply reservoir during vehicle operation or, at
the latest, after receiving the first warning mes-
sage via the on-board computer.
Low ambient temperatures
DEF freezes at a temperature of approximately
12‡(Ò11 †). The vehicle is equipped with a DEF
preheating system at the factory. Winter oper-
ation is therefore also guaranteed at tempera-
tures under 12 ‡ (Ò11 †).
iIf you add DEF at temperatures below 12 ‡
(Ò11 †) it is possible that the level is not
shown correctly due to the frozen DEF. Drive for at least 20 minutes (heating phase in
the tank activated) and then stop the vehicle
for at least 30 seconds. The level is then
shown correctly.
Additives
!Do not mix DEF with any additives and do
not dilute DEF with tap water. Otherwise, the
exhaust gas aftertreatment may be damaged.
Observe the MB Specifications for Service
Products, Sheet No. 352.0.
Damage that arises through the use of addi-
tives or tap water will invalidate the New Vehi-
cle Limited Warranty.
Storage
!Containers made of aluminum, copper, cop-
per alloys as well as unalloyed or galvanized
steel are not suitable for storing DEF. If stored
in these types of containers, DEF could cause
constituents of these metals to dissolve and
cause irreparable damage to the exhaust gas
aftertreatment.
Damage caused by such impurities in the DEF
will invalidate the New Vehicle Limited War-
ranty.
Only store DEF in containers made of high-alloy
Cr‑Ni steel or Mo‑Cr‑Ni steel in accordance with DIN EN 10 088 ‑
1/2/3 or plastic containers
made of polypropylene or polyethylene.
Purity
!Impurities in DEF (e.g. caused by other ser-
vice products, cleaning agents, dust, etc.)
result in increased emissions, malfunctions,
catalytic converter damage or engine dam-
age.
The purity of DEF is essential to prevent mal-
functions in the exhaust gas aftertreatment.
If DEF is pumped out of the DEF tank, e.g. during
repair work, the same liquid must not be used to
refill the tank. Its purity is no longer guaranteed.
Disposal
Observe country-specific laws and regulations
when disposing of DEF.
% Environmental note
Dispose of DEF in an environmentally responsi-
ble manner.
276Service products and capacities
Technical data
