XTurn DEF cap : counter-clockwise and
remove it.
X Turn DEF filler cap ; counter-clockwise
and open it.
Filler cap ; is secured with a plastic strip.
X
Unscrew the protective cap from DEF refill
bottle =.
X Place DEF refill bottle = on the filler neck
as shown and screw it on clockwise until
hand-tight.
X Press DEF refill bottle = downward.
The DEF tank is filled. This may take up to
one minute.
iTo top up between service intervals, fill
the DEF tank with approximately 1 gal
(3.8 l) of DEF. 1 gal (3.8 l) DEF is equivalent
to approximately 2 DEF refill bottles. Then
have the DEF supply checked at a qualified specialist workshop and completely refilled
if necessary.
X Release DEF refill bottle =.
When DEF refill bottle = is no longer
pressed down, filling stops. DEF refill bottle = can be removed when it has been only
partially emptied.
X Turn DEF refill bottle = counter-clockwise
and remove it.
X Place DEF filler cap ; on the filler neck and
turn it clockwise.
X Replace DEF cover : as shown and turn it
clockwise as far as it will go.
X Fold the cargo compartment floor down.
X Close the tailgate.
X Drive faster than 10 mph (16 km/h).
The
Check Additive See Operator's
Manual message goes out after approx-
imately one minute.
iIf the Check Additive See OperaZ
tor's Manual message is still shown in
the multifunction display, add an additional bottle of DEF.
For further information on DEF, see
( Y page 376).
Refueling167
Driving and parking
Z
Bio-diesel – FAME (fatty acid methyl ester)Mercedes-Benz USA approves the use of bio-diesel B5 for all BlueTEC diesel engines. The
concentration of bio-diesel in the ULSD may
not exceed 5% by volume.
Pure bio-diesel and diesel fuel with a higher
percentage of bio-diesel, such as B20, can
damage the engine and the fuel system. For
this reason, they are not approved.
For more information, consult the gas station
staff. The bio-diesel B5 label on the gasoline
pump must clearly state that the standard for
ULSD has been fulfilled. If the label is not
clear, do not refuel the vehicle.
Do not refuel your vehicle with fuels unless
they have been approved by Mercedes-Benz.
Information on refueling ( Y page 163).
Low outside temperatures
iDiesel fuel with improved cold flow prop-
erties is available during the winter months. Further information about fuel properties
can be obtained from oil companies, e.g. at gas stations.
DEF
Important safety notes
Comply with the important safety notes for
service products when handling DEF
( Y page 373).
DEF is a water-soluble fluid for the exhaust
gas aftertreatment of diesel engines. It is: R not poisonous
R colorless and odorless
R 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 expe-
rience 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 approx-
imately 12 ‡ (-11 †). The vehicle is delivered
from the factory equipped with a DEF pre-
heating 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 after-
treatment system.
Purity
! Impurities in DEF (e.g. due to other ser-
vice products, cleaning agents or dust) lead to:
R increased emission values
R damage to the catalytic converter
R engine damage
R malfunctions in the BlueTEC exhaust gas
aftertreatment system
Assuring the purity of DEF is particularly
important with respect to avoiding malfunc-
tions in the BlueTEC exhaust gas aftertreat-
ment system.
If DEF is pumped out of the DEF tank, e.g.
during repair work, it must not be returned to
the tank. The purity of the fluid can no longer
be guaranteed.
Filling capacities
ModelTotal capacity
GLK 250 BlueTEC
4MATIC7.3 US gal (27.5 l)
376Service products and filling capacities
Technical data
