Page 437 of 489

For further information on displaying this
message, refer to the "Checking the tyre pres-
sure electronically" section (Y page 434).
Important safety notes It is the driver's responsibility to set the tyre
pressure to the recommended cold tyre pres-
sure suitable for the operating situation
(Y page 432). Note that the correct tyre pres-
sure for the current operating situation must
first be taught-in to the tyre pressure monitor. If there is a substantial loss of pressure, the
warning threshold for the warning message is aligned to the reference values taught-in.
Restart the tyre pressure monitor after
adjusting to the cold tyre pressure
(Y page 435). The current pressures are
saved as new reference values. This will
ensure that a warning message will only
appear if the tyre pressure drops significantly.
The tyre pressure monitor does not warn you
of an incorrectly set tyre pressure. Observe
the notes on the recommended tyre pressure
(Y page 432).
The tyre pressure monitor is not able to warn
you of a sudden loss of pressure, e.g. if the
tyre is penetrated by a foreign object. In the
event of a sudden loss of pressure, bring the
vehicle to a halt by braking carefully. Avoid
abrupt steering manoeuvres.
The tyre pressure monitor has a yellow warn-
ing lamp in the instrument cluster for indicat- ing a pressure loss or malfunction. Depending
on how the warning lamp flashes or lights up, a tyre pressure that is too low or a malfunc-
tion in the tyre pressure monitor is indicated:
R if the warning lamp is lit continuously, the
tyre pressure on one or more tyres is sig-
nificantly too low. The tyre pressure moni-
tor is not malfunctioning.
R if the warning lamp flashes for around a
minute and then remains lit constantly, the
tyre pressure monitor is malfunctioning.
In addition to the warning lamp, a message
appears in the multifunction display. Further
information can be found under (Y page 343).If the tyre pressure monitor is malfunctioning,
it may take more than ten minutes for the tyre
pressure warning lamp to inform you of the
malfunction by flashing for approximately one minute and then remaining lit. When the fault
has been rectified, the tyre pressure warning lamp goes out after you have driven for a few
minutes.
The tyre pressure values indicated by the on- board computer may differ from those meas-
ured at a filling station using a pressure
gauge. The tyre pressures shown by the on-
board computer refer to those measured at
sea level. At high altitudes, the tyre pressure
values indicated by a pressure gauge are
higher than those shown by the on-board
computer. In this case, do not reduce the tyre
pressures.
The operation of the tyre pressure monitor
can be affected by interference from radio
transmitting equipment (e.g. radio head-
phones, two-way radios) that may be being
operated in or near the vehicle.
Checking the tyre pressure electroni-
cally X
Make sure that the key is in position 2
(Y page 181) in the ignition lock.
X Use ò on the steering wheel to call up
the list of menus.
X Press the 9or: button on the steer-
ing wheel to select the Service Servicemenu.
X Press the abutton.
X Press the 9or: button to select
Tyre pressure
Tyre pressure .
X Press the abutton.
The current tyre pressure for each wheel
will be displayed in the multifunction dis-
play.
If the vehicle has been parked for over
20 minutes, the Tyre
Tyre pressures pressures will
willbe
be
displayed after a few minutes of
displayed after a few minutes of
driving
driving message appears.
After a teach-in period, the tyre pressure
monitor automatically detects new wheels or 434
Tyre pressureWheels and tyres
Page 442 of 489

X
Vehicles with KEYLESS-GO start-func-
tion or KEYLESS-GO: remove the Start/
Stop button from the ignition lock
(Y page 181).
X If included in the vehicle equipment,
remove the tyre-change tool kit from the
vehicle.
X Secure the vehicle to prevent it from rolling
away.
i Apart from some country-specific var-
iants, vehicles are not equipped with tyre-
changing tools. Some tools for changing a
wheel are specific to the vehicle. For more information on which tools are required to
perform a wheel change on your vehicle,
consult a qualified specialist workshop.
Necessary wheel-changing tools may
include, for example:
R jack
R wheel chock
R wheel wrench
R centring pin
Securing the vehicle against rolling
away If your vehicle is equipped with a wheel chock,
it can be found in the tyre-change tool kit
(Y page 407).
The folding wheel chock is an additional
securing measure to prevent the vehicle from
rolling away, for example when changing a
wheel. X
Fold both plates upwards :.
X Fold out lower plate ;.
X Guide the lugs on the lower plate fully into
the openings in base plate =. Securing the vehicle on level ground
X On level ground: place chocks or other
suitable items under the front and rear of
the wheel that is diagonally opposite the
wheel you wish to change. Securing the vehicle on slight downhill gradients
X On slight downhill gradients: place
chocks or other suitable items in front of
the wheels of the front and rear axle.
Raising the vehicle G
WARNING
If you do not position the jack correctly at the appropriate jacking point of the vehicle, the
jack could tip over with the vehicle raised.
There is a risk of injury.
Only position the jack at the appropriate jack-
ing point of the vehicle. The base of the jack Changing a wheel
439Wheels and tyres
Z
Page 465 of 489

An emergency spare wheel may also be fitted
against the direction of rotation. Observe the
time restriction on use as well as the speed
limitation specified on the emergency spare
wheel.
Replace the tyres after six years at the latest,
regardless of wear. This also applies to the
emergency spare wheel.
If you are driving with the collapsible emer-
gency spare wheel fitted, the tyre pressure
loss warning system or the tyre pressure
monitor cannot function reliably. Only restart the tyre pressure loss warning system/tyre
pressure monitor when the defective wheel
has been replaced with a new wheel.
Vehicles with tyre pressure monitor: after
mounting an emergency spare wheel, the sys- tem may still display the tyre pressure of the
removed wheel for a few minutes. The value
displayed for the mounted emergency spare
wheel is not the same as the current tyre
pressure of the emergency spare wheel.
If you are driving with the emergency spare
wheel fitted, the tyre pressure loss warning
system cannot function reliably. Only restart
the tyre pressure loss warning system when
the defective wheel has been replaced with a
new wheel. Removing the emergency spare wheel
The emergency spare wheel is secured in the
emergency spare wheel bag in the boot.
X Open the boot.
X Detach the fastening straps.
X Unhook retaining spring hooks of fastening
straps from the retainers.
X Remove the emergency spare wheel bag
with the emergency spare wheel.
X Open the bag and remove the emergency
spare wheel.
Observe the instructions and safety notes in
the "Fitting a wheel" section (Y page 438). Inflating the collapsible emergency
spare wheel
! Inflate the collapsible emergency spare
wheel using the tyre inflation compressor
before lowering the vehicle. The wheel rim
could otherwise be damaged.
! Do not operate the tyre inflation com-
pressor for longer than eight minutes at a
time without a break. It may otherwise
overheat.
The tyre inflation compressor can be oper-
ated again once it has cooled down. X
Mount the collapsible emergency spare
wheel as described (Y page 437).
The collapsible emergency spare wheel
must be mounted before it is inflated.
X Pull connector ?and the air hose out of
the housing.
X Remove the cap from the valve on the col-
lapsible emergency spare wheel.
X Screw union nut :of the air hose onto the
valve.
X Make sure on/off switch Aof the tyre
inflation compressor is set to 0.
X Insert plug ?into the cigarette lighter
socket or into a 12 V socket in your vehicle.
X Press the Start/Stop button once.
or X Turn the key to position 1in the ignition
lock. 462
Emergency spare wheelWheels and tyres