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 322). 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 318).
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.
i In addition to the warning lamp, a mes-
sage appears in the multifunction display.
Further information can be found under
(Y page 243).
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 141) in the ignition lock.
X Press the =or; button on the steer-
ing wheel to select the Serv. Serv.menu.
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
new sensors. As long as a clear allocation of
the tyre pressure values to the individual
wheels is not possible, the Tyre pressure Tyre pressure
monitor active
monitor active display message is shown
instead of the tyre pressure display. The tyre
pressures are already being monitored.
i If an emergency spare wheel is fitted, for
a few minutes the system may continue to
show the tyre pressure of the wheel that
has been removed. If this occurs, note that the value displayed for the position where Tyre pressure
321Wheels and tyres Z
the spare wheel is fitted is not the same as
the current tyre pressure of the emergencyspare wheel.
Warning messages of the tyre pressure monitor If the tyre pressure monitor detects a pres-
sure loss in one or more tyres, a warning mes-
sage is shown in the multifunction display and the yellow tyre pressure monitor warning
lamp comes on.
R If the Rectify tyre pressure
Rectify tyre pressure message
appears in the multifunction display, the
tyre pressure in at least one tyre is too low and must be corrected at the next oppor-
tunity.
R If the Check tyre(s)
Check tyre(s) message appears in
the multifunction display, the tyre pressure
in one or more tyres has dropped signifi-
cantly and the tyres must be checked.
R If the Warning tyre defect
Warning tyre defect message
appears in the multifunction display, the
tyre pressure in one or more tyres has drop- ped suddenly and the tyres must be
checked.
Observe the instructions and safety notes in
the display messages in the "Tyres" section
(Y page 243).
i If the wheel positions on the vehicle are
interchanged, the tyre pressures may be
displayed for the wrong positions for a
short time. After a few minutes of driving,
this is rectified and the tyre pressures are
displayed for the correct positions.
Restarting the tyre pressure monitor When you restart the tyre pressure monitor,
all existing warning messages are deleted and
the warning lamps go out. The monitor uses
the currently set tyre pressures as the refer-
ence values for monitoring. In most cases, the tyre pressure monitor will automatically
detect the new reference values after you
have changed the tyre pressure. However,
you can also define reference values man- ually as described here. The tyre pressure
monitor then monitors the new tyre pressure
values.
X Use the table on the inside of the fuel filler
flap to ensure that the tyre pressure is set
correctly in all four tyres for the current
operating conditions.
Also observe the notes in the section on
tyre pressures (Y page 318).
X Make sure that the key is in position 2in the
ignition lock.
X Press the =or; button on the steer-
ing wheel to select the Serv.
Serv. menu.
X Press the 9or: button to select
Tyre pressure Tyre pressure.
X Press the abutton.
The multifunction display shows the cur-
rent tyre pressure for the individual tyres or
the Tyre pressures will be dis‐ Tyre pressures will be dis‐
played
played after
aftera
afew
few minutes
minutes of
ofdriv‐
driv‐
ing
ing message.
X Press the :button.
The Use current pressures as new
Use current pressures as new
reference values
reference values message appears in
the multifunction display.
If you wish to confirm the restart: X Press the abutton.
The Tyre press. monitor restarted
Tyre press. monitor restarted
message appears in the multifunction dis-
play.
After you have driven for a few minutes, the system checks whether the current tyre
pressures are within the specified range.
The new tyre pressures are then accepted
as reference values and monitored.
If you wish to cancel the restart:
X Press the %button.
The tyre pressure values stored at the last
restart will continue to be monitored. 322
Tyre pressureWheels and tyres
Emergency spare wheel
Important safety notes
G
WARNING
The wheel/tyre dimensions and the tyre type of the spare wheel/emergency spare wheel
and the wheel to be replaced may differ. Fit-
ting a spare wheel/emergency spare wheel
may severely impair the driving characteris-
tics. There is a risk of accident.
To prevent hazardous situations:
R Adapt your driving style accordingly and
drive carefully.
R Never fit more than one spare wheel/emer-
gency spare wheel if the dimensions are
different to those of the wheel being
replaced.
R Only use a spare wheel/emergency spare
wheel briefly if the dimensions are different to those of the wheel being replaced.
R Do not switch off ESP ®
.
R Have the spare wheel/emergency spare
wheel in question replaced at the nearest
qualified specialist workshop. Make sure
that the wheel/tyre dimensions and tyre
type are correct.
When using an emergency spare wheel or
spare wheel of a different size, you must not
exceed the maximum speed of 80 km/h.
Snow chains must not be fitted to emergency
spare wheels. General notes
You should regularly check the pressure of all your tyres, including the emergency spare
wheel, particularly prior to long trips, and cor-
rect the pressure as necessary (Y page 318).
The applicable value is found on the wheel or
under "Technical data" (Y page 337).
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.
i If you are driving with the collapsible
emergency spare wheel fitted, the tyre
pressure loss warning system or the tyre
pressure monitor cannot function reliably.
Do not restart the tyre pressure loss warn-
ing system/tyre pressure monitor until the
defective wheel has been replaced with a
new wheel.
Vehicles with a tyre pressure monitor:
for a few minutes after an emergency spare wheel is fitted, the system may still display
the tyre pressure of the removed wheel.
The value displayed for the mounted emer-
gency spare wheel is not the same as the
current tyre pressure of the emergency
spare wheel. Removing the emergency spare wheel
(Example)
The collapsible emergency spare wheel can
be found in the stowage well under the boot
floor. X Lift and remove the reversible floor panel in
the boot (Y page 266).
X Turn retaining screw ;anti-clockwise and
remove it.
X Remove collapsible emergency spare
wheel :. 334
Emergency spare wheelWheels and tyres