
Check
Tirepressure specifications
Important safety notes
GWARNING
Tireswithtirepressuresthatare toolow or
toohigh are associated withthefollowing
hazards:
Rthey can burst, in particular if thevehicle is
heavily laden or when driven at high
speeds.
Rthetires can wear excessively and/or
unevenly, whichcan severely impairtire
traction.
Rthe driving, steeringand braking
characteristics may be severely impaired.
There isarisk of accident.
Follow recommended tireinflation pressures
and checkthe pressure of all the tires
including the spare wheel:
Rmonthly, at least
Rif the load changes
Rbefore beginningalong journey
Runder different operating conditions,e.g.
off-road driving
If necessary, correct the tire pressure.
iThe specifications on the sample Tire and
Loading Information placard and tire
pressure tables are examples. Tire
pressure specifications are vehicle-specific
and may deviate from the data shown here.
The tire pressure specifications that are
valid for your vehicle can be found on the
Tire and Loading Information placard and
tire pressure table on the vehicle.
General notes
The recommended tire pressures for the tires
mounted at the factory can be found on the
labelsdescribed here.
Operation with the emergency spare
wheel(Ypage 367).
Further information on tire pressures can be
obtained ataqualified specialist workshop.
Tire and Loading Information placard
Recommended tire pressures
The Tire and Loading Information placard is
on the B-pillar on the driver's side
(Ypage 345).
The Tire and Loading Information placard
contains the recommended tire pressures for
cold tires. The recommended tire pressures
are valid for the maximum permissible load
and up to the maximum permissible vehicle
speed.
Tire pressuretable
The tire pressure table is on the inside of the
fuel filler flap.
Example: tire pressure table for all tires permittedfor this vehicle by the factory
The tire pressure table contains the
recommended pressures for cold tires for
various operating conditions, i.e. differing
load and speed conditions.
338Check
Wheels and tires

The tires are cold:
Rif the vehicle has been parked without
direct sunlight on the tires for at least three
hours and
Rif the vehicle has been driven for less than
1mile (1.6 km).
The tire temperature changes depending on
the outside temperature, the vehicle speed
and the tire load. If the tire temperature
changes by 18‡(10 †), the tire pressure
changes by approximately 10 kPa (0.1 bar/
1.5 psi). Take this into account when
checking the pressure of warm tires. Only
correctthe tire pressure if it is too low for the
current operating conditions. If you check the
tire pressure when the tires are warm, the
resulting value will be higher than if the tires
were cold. This is normal. Do not reduce the
tire pressure to the value specified for cold
tires. The tire pressure would otherwise be
too low.
Observe the recommended tire pressures for
cold tires:
Ron the Tire and Loading Information placard
on the B-pillar on the driver's side
Rin the tire pressure table on the inside of
the fuel filler flap
Ron the yellow label on the emergency spare
wheel (depending on the vehicle
equipment)
Underinflated or overinflated tires
Underinflation
GWARNING
Tires with pressure that is too low can
overheat and burst asaconsequence. In
addition, they also suffer from excessive and/
or irregular wear, which can severely impair
the braking properties and the driving
characteristics. There isarisk of an accident.
Avoid tire pressures that are too low in all the
tires, including the spare wheel.
Underinflated tires may:
Roverheat, leading to tire defects
Rhave an adverse effect on handling
characteristics
Rwear quickly and unevenly
Rhave an adverse effect on fuel consumption
Overinflation
GWARNING
Tires with excessively high pressure can burst
because they are damaged more easily by
road debris, potholes etc. In addition, they
also suffer from irregular wear, which can
severely impair the braking properties and the
driving characteristics. There isarisk of an
accident.
Avoid tire pressures that are too high in all the
tires, including the spare wheel.
Overinflated tires may:
Rincrease the braking distance
Rhave an adverse effect on handling
characteristics
Rwear quickly and unevenly
Rhave an adverse effect on ride comfort
Rbe more susceptible to damage
Maximum tire pressures
Example: maximum permissible tire
pressure
Never exceed the maximum permissible tire
inflation pressure. Always observe the
recommended tire pressure for your vehicle
340Check
Wheels and tires

Example: current tire pressure display
Important safety notes
GWARNING
Each tire,including the spare (ifprovided),
should be checked at least once every two
weeks when cold and inflated to the pressure
recommended by the vehiclemanufacturer
on the Tire and Loading Information placard
on the driver'sdoor B-pillar or the tire
pressure label on the inside of the fuel filler
flap.Ifyour vehicle has tires ofadifferent size
than the size indicated on the Tire and Loading
Information placard or, if available, the tire
pressure label, you should determinethe
proper tire pressure for those tires.
As an added safety feature, your vehicle has
been equipped withatire pressure monitoring
system (TPMS) that illuminatesalow tire
pressure 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. Drivingona
significantly underinflated 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 notasubstitute for proper tire
maintenance, and it is the driver's
responsibility to maintain correcttire
pressure, even if underinflation has not
reached the level to trigger illumination of the
TPMS low tire pressure 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
system detectsamalfunction, the warning
lamp will flash for approximatelyaminute and
then remain continuously illuminated. This
sequence will be repeated every time the
vehicle is started as long as the malfunction
exists. When the malfunction indicator is
illuminated, the system may not be able to
detect or signal low tire pressure as intended.
TPMS malfunctions may occur foravariety of
reasons, including the installation of
incompatible 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
(Ypage 338). Note that the correcttire
pressure for the current operating situation
must first be taught-in to the tire pressure
monitor. If there isasubstantial loss of
pressure, the warning threshold for the
warning message is aligned to the reference
values taught-in.Restart the tire pressure
monitor after adjustingthe pressure of the
cold tires (Ypage 345). The current
pressures are saved as new reference values.
Asaresult,awarning 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
(Ypage 338).
The tire pressure monitor is not able to warn
you ofasudden loss of pressure, e.g. if the
tire is penetrated byaforeign object. In the
event ofasudden loss of pressure, bring the
vehicle toahalt by brakingcarefully. Avoid
sudden steering movements
Check343
Wheels and tires
Z

The tire pressure monitor hasayellow
warning lamp in the instrument cluster for
indicatingapressure loss or malfunction.
Whether the warning lamp flashes or lights up
indicates whetheratire pressure is too low or
the tire pressure monitor is malfunctioning:
Rif the warning lamp is lit continuously, the
tire pressure on one or more tires is
significantly too low. The tire pressure
monitor is not malfunctioning.
Rif the warning lamp flashes for around a
minute and then remains lit constantly, the
tire pressure monitor is malfunctioning.
If the tire pressure monitor is malfunctioning,
it may take more than ten minutes for the tire
pressure warning lamp to inform you of the
malfunction by flashing for approximately one
minute and then remaining lit. When the
malfunction has been rectified, the tire
pressure warning lamp goes out afterafew
minutes of driving.
The tire pressure values indicated by the on-
board computer may differ from those
measured atagas station withapressure
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 byapressure gauge are
higher than those shown by the on-board
computer.Inthis case, do not reduce the tire
pressures.
The operation of the tire pressure monitor can
be affected by interference from radio
transmitting equipment (e.g. radio
headphones, two-way radios) that may be
being operated in or near the vehicle.
Checking the tire pressure
electronically
XMake sure that the SmartKey is in position
2(Ypage 147) in the ignition lock .
XPress the \nor button on the
steering wheel to select theServ.menu.
XPress the or button to select
Tire Pressure.
XPress the button.
The current tire pressure of each tire is
shown in the multifunction display.
If the vehicle was parked for longer than
20 minutes,theTirepressureswillbe
displayed after drivingafew
minutesmessage is shown.
Afterateach-in process, the tire pressure
monitor automatically detects new wheels or
new sensors. As long asaclear allocation of
the tire pressure value to the individual
wheels is not possible, theTire Pressure
Monitor Activedisplaymessage is shown
instead of the tire pressure display. The tire
pressures are already being monitored.
iIf an emergency spare wheel is mounted,
the system may continue to show the tire
pressure of the wheel that has been
removed forafew minutes. If this occurs,
note that the value displayed for the
position where the spare wheel is mounted
is not the same as the current tire pressure
of the emergency spare wheel.
Tire pressuremonitor warning
messages
If the tire pressure monitor detectsapressure
loss in one or more tires,awarning message
is shown in the multifunction displayand the
yellow tire pressure monitor warning lamp
comes on.
RIf theCorrect Tire Pressuremessage
appears in the multifunction display, the
tire pressure in at least one tire is too low
and must be corrected at the next
opportunity.
RIf theCheck Tire Pressuremessage
appears in the multifunction display, the
tire pressure in one or more tires has
dropped significantly and the tires must be
checked.
RIf theTire Malfunctionappears in the
multifunction display, the tire pressure in
344Check
Wheels and tires