2015 MERCEDES-BENZ GLK-Class fuel cap release

residues crystallize after time and contam-
inate the affected surfaces.
! DEF is not a fuel additive and must not be
added to the fuel tank. If DEF is added to
the fuel tank, this can lead to engine dam-
age.
! Only screw on the DEF refill bottle hand-
tight. It could otherwise be damaged.
The DEF filler neck is under the cargo com-
partment floor.
X Switch the ignition off.
X Open the tailgate.
X Lift up the cargo compartment floor
(Y page 314). X
Turn DEF cap 0043counter-clockwise and
remove it. X
Turn DEF filler cap 0044counter-clockwise
and open it.
Filler cap 0044is secured with a plastic strip. X
Unscrew the protective cap from DEF refill
bottle 0087.
X Set DEF refill bottle 0087as shown on the
filler neck and screw it on hand-tight.
X Press DEF refill bottle 0087downward.
The DEF tank is filled. This may take up to
one minute.
i To 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 0087.
When DEF refill bottle 0087is no longer
pressed down, filling stops. DEF refill bottle 0087 can be removed when it has been only
partially emptied.
X Turn DEF refill bottle 0087counter-clockwise
and remove it.
X Place DEF filler cap 0044on the filler neck and
turn it clockwise. Refueling
167Driving and parking Z

0043
Example: maximum permissible tire pres-
sure
i The actual values for tires are vehicle-
specific and may deviate from the values in
the illustration. Checking the tire pressures
Important safety notes Observe the "tire pressure information" sec-
tion (Y page 336).
Information on air pressure for the tires on
your vehicle can be found:
R on the vehicle's Tire and Loading Informa-
tion placard on the B-pillar
R on the tire pressure label on the fuel filler
flap
R in the "Tire pressure information" section
Checking tire pressures manually To determine and set the correct tire pres-
sure, proceed as follows:
X Remove the valve cap of the tire that is to
be checked.
X Press the tire pressure gauge securely onto
the valve.
X Read the tire pressure and compare it with
the recommended value on the Tire and
Loading Information placard on the B-pillar
on the driver's side of your vehicle.
X If necessary, increase the tire pressure to
the recommended value (Y page 336).X
If the tire pressure is too high, release air by
pressing down the metal pin in the valve
using the tip of a pen, for example. Then,
check the tire pressure again using the tire
pressure gauge.
X Screw the valve cap onto the valve.
X Repeat these steps for the other tires. Tire pressure monitor
General notes If a tire pressure monitor is installed, the vehi-
cle's wheels have sensors that monitor the
tire pressures in all four tires. The tire pres-
sure monitor warns you if the pressure drops
in one or more of the tires. The tire pressure
monitor only functions if the corresponding
sensors are installed on all wheels.
Information on tire pressures is displayed in
the multifunction display. After a few minutes of driving, the current tire pressure of each
tire is shown in the Service
Service menu of the mul-
tifunction display. Example: current tire pressure display
For information on the message display, refer to the "Checking the tire pressure electroni-
cally" section (Y page 341).
Important safety notes G
WARNING
Each tire, including the spare (if provided),
should be checked at least once a month
when cold and inflated to the pressure rec-
ommended by the vehicle manufacturer on
the Tire and Loading Information placard on
the driver's door B-pillar or the tire pressure
label on the inside of the fuel filler flap. If your Tire pressure
339Wheels and tires
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
i Diesel 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 Model Total capacity
GLK 250 BlueTEC
7.3 US gal
(27.5 l) 376
Service products and filling capacitiesTechnical data