Page 346 of 374

Information on the message display can be
found in the "Checking the tire pressure elec-
tronically" section ( Y
page 345).
Important safety notes
G WARNING
Each tire, including the spare (if provided),
should be checked at least once every two
weeks when cold and inflated to the pressure
recommended by the vehicle manufacturer
on the Tire and Loading Information placard
on the driver's door B-pillar or the tire pres-
sure label on the inside of the fuel filler flap. If
your vehicle has tires of a different size than
the size indicated on the Tire and Loading
Information placard or, if available, the tire
pressure label, you should determine the
proper tire pressure for those tires.
As an added safety feature, your vehicle has
been equipped with a tire pressure monitoring
system (TPMS) that illuminates a low tire pres-
sure telltale when one or more of your tires
are significantly underinflated. Accordingly,
when the low tire pressure telltale lights up,
you should stop and check your tires as soon
as possible, and inflate them to the proper
pressure. Driving on a significantly underin-
flated tire causes the tire to overheat and can
lead to tire failure.
Underinflation also reduces fuel efficiency
and tire tread life, and may affect the vehicle's
handling and stopping ability. Please note that
the TPMS is not a substitute for proper tire
maintenance, and it is the driver's responsi-
bility to maintain correct tire pressure, even if
underinflation has not reached the level to trigger illumination of the TPMS low tire pres-
sure telltale.
Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate when
the system is not operating properly. The
TPMS malfunction indicator is combined with
the low tire pressure telltale. When the sys-
tem detects a malfunction, the warning lamp
will flash for approximately a minute and then
remain continuously illuminated. This
sequence will be repeated every time the vehi-
cle is started as long as the malfunction
exists. When the malfunction indicator is illu-
minated, the system may not be able to detect
or signal low tire pressure as intended.
TPMS malfunctions may occur for a variety of
reasons, including the installation of incom-
patible replacement or alternate tires or
wheels on the vehicle that prevent the TPMS
from functioning properly. Always check the
TPMS malfunction telltale after replacing one
or more tires or wheels on your vehicle to
ensure that the replacement or alternate Tires
and wheels allow the TPMS to continue to
function properly.
It is the driver's responsibility to set the tire
pressure to that recommended for cold tires
which is suitable for the operating situation
( Y
page 339). Note that the correct tire pressure
for the current operating situation must first be
taught-in to the tire pressure monitor. If a sub-
stantial loss of pressure occurs, the warning
threshold for the warning message is aligned to
the taught-in reference values. Restart the tire
pressure monitor after adjusting the pressure of
the cold tires ( Y
page 345). The current pres-
sures are saved as new reference values. As a
result, a warning message will appear if the tire
pressure drops significantly.
The tire pressure monitor does not warn you of
an incorrectly set tire pressure. Observe the
notes on the recommended tire pressure
( Y
page 339).
The tire pressure monitor is not able to warn you
of a sudden loss of pressure, e.g. if the tire is
penetrated by a foreign object. In the event of a
su dden loss of pressure, bring the vehicle to a
halt by braking carefully. Avoid abrupt steering
movements.344
Tire pressure
Wheels and tires
Page 347 of 374

The tire pressure monitor has a yellow warning
lamp in the instrument cluster for indicating
pressure loss or a malfunction. Whether the
warning lamp flashes or lights up indicates
whether a tire pressure is too low or the tire
pressure monitor is malfunctioning: R
if the warning lamp is lit continuously, the tire
pressure on one or more tires is significantly
too low. The tire pressure monitor is not mal-
functioning. R
if the warning lamp flashes for around a
minute and then remains lit constantly, the
tire pressure monitor is malfunctioning.
In addition to the warning lamp, a message
appears in the multifunction display. Observe
the information on display messages
( Y
page 250).
It may take up to ten minutes for a malfunction
of the tire pressure monitor to be indicated. A
malfunction will be indicated by the tire pres-
sure warning lamp flashing for approximately
one minute and then remaining lit. When the
malfunction has been rectified, the tire pressure
warning lamp goes out after a few minutes of
driving.
The tire pressure values indicated by the on-
board computer may differ from those meas-
ured at a gas station with a pressure gauge. The
tire pressures shown by the on-board computer
refer to those measured at sea level. At high
altitudes, the tire pressure values indicated by a
pressure gauge are higher than those shown by
the on-board computer. In this case, do not
reduce the tire pressures.
The operation of the tire pressure monitor can
be affected by interference from radio transmit-
ting equipment (e.g. radio headphones, two-way
radios) that may be being operated in or near the
vehicle.
Checking the tire pressure electroni-
cally X
Make sure that the SmartKey is in position H
( Y
page 132) in the ignition lock. X
Press
Page 369 of 374

You will usually find information about the fuel
quality on the pump. If you cannot find the label
on the fuel pump, ask the gas station staff.
Information on refueling ( Y
page 149).
Low outside temperatures
i Diesel fuel with improved cold flow proper-
ties 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 ser-
vice products when handling DEF ( Y
page 364).
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 experi-
ence 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
-11 †. The vehicle is delivered from the factory
equipped with a DEF preheating system. Winter
operation can thus be guaranteed even at tem-
peratures below -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 sys-
tem. Purity
! Impurities in DEF (e.g. due to other service
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 impor-
tant with respect to avoiding malfunctions in the
BlueTEC exhaust gas aftertreatment 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 guaran-
teed.
Filling capacities Model Total capacity
All models
29.1 US qt
(27.5 l)
Engine oil
General notes
! Do not use engine oil or an oil filter with
specifications deviating from those expressly
required for the prescribed service intervals.
Do not change the engine oil or oil filter in
order to set replacement intervals longer than
those prescribed. This could otherwise cause
damage to the engine or exhaust gas after-
treatment.
Follow the instructions on the service interval
display for changing the engine oil. This couldService products and filling capacities 367
Technical data Z