
reduces fuel efficiency and tire tread life, andmay affect the vehicle's handling and stop-
ping ability.
Please note that the TPMS is not a substitute for proper tire maintenance, and it is the driv-
er's responsibility to maintain correct tire
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 if the
system is not operating properly. The TPMS
malfunction indicator is combined with the
low tire pressure telltale. When the system
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 malfunctionexists.
When the malfunction indicator is illuminated,
the system may not be able to detect or signal
low tire pressure as intended. TPMS malfunc- tions may occur for a variety of reasons,
including the installation of incompatible
replacement or alternate tires or wheels on
the vehicle that prevent the TPMS from func-
tioning properly. Always check the TPMS mal-
function telltale after replacing one or more
tires or wheels on your vehicle to ensure that
the replacement or alternate tires and wheelsallow the TPMS to continue to function prop-
erly.
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 315). Note that the correct tire pres-
sure for the current operating situation must
first be taught-in to the tire 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 tire pressure monitor after adjust-
ing the pressure of the cold tires( Y page 322). The current pressures are
saved as new reference values. As a result, a warning message will appear if the tire pres-
sure 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 315).
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 sudden loss of pressure, bring the
vehicle to a halt by braking carefully. Avoid
abrupt steering maneuvers.
The tire pressure monitor has a yellow warn-
ing lamp in the instrument cluster for indicat- ing a pressure loss or malfunction. Whether
the warning lamp flashes or lights up indi-
cates 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 signif-
icantly too low. The tire pressure monitor is
not malfunctioning.
R if the warning lamp flashes for around a
minute and then remains lit constantly, the
tire pressure monitor is malfunctioning.
iIn addition to the warning lamp, a mes-
sage appears in the multifunction display.
Observe the information on display mes-
sages ( Ypage 236).
It may take up to ten minutes for you to be
informed about a malfunction in the tire pres-
sure monitor. The tire pressure warning lamp informs you about 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 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 val-
ues indicated by a pressure gauge are higher
Tire pressure321
Wheels and tires
Z

found on the wheel or under "Technical data"( Y page 346).
An emergency spare wheel may also be
mounted against the direction of rotation.
Observe the time restriction on use as well as
the speed limitation specified on the emer-
gency spare wheel.
Replace the tires after six years at the latest,
regardless of wear. This also applies to the
emergency spare wheel.
iWhen you are driving with the collapsible
spare wheel mounted, the tire pressure
loss warning system or the tire pressure
monitor cannot function reliably. Only
restart the tire pressure loss warning sys-
tem/the tire pressure monitor when the
damaged wheel has been replaced with a
new wheel.
Vehicles with tire pressure monitor:
after mounting an emergency spare wheel,
the system may still display the tire pres-
sure of the removed wheel for a few
minutes. The value displayed for the moun- ted emergency spare wheel is not the sameas the current tire pressure of the emer-
gency spare wheel.
Removing the emergency spare wheel
(Example)
The collapsible spare wheel can be found in
the stowage well under the trunk floor. X
Lift and remove the reversible floor panel in
the trunk ( Ypage 260).
X Turn retaining screw ;counter-clockwise
and remove it.
X Remove collapsible spare wheel :.
Always observe the instructions and safety
notes in the "Mounting a wheel" section( Y page 335).
Stowing the emergency spare wheel
!
Only place the collapsible spare wheel in
the vehicle when it is dry. Otherwise, mois-
ture may get into the vehicle.
Take the following steps to stow a used col-
lapsible spare wheel. Otherwise, the collaps-
ible spare wheel will not fit in the trunk in the
intended manner. Mercedes-Benz recom-
mends that you have this work carried out at
a qualified specialist workshop.
X Unscrew the valve cap from the valve.
X If possible, unscrew the valve insert from
the valve and release the air.
iFully deflating the tires can take a few
minutes.
X Screw the valve insert back into the valve.
X Screw the valve cap back on.
X Pull the protective sheet provided with the
spare wheel over the collapsible spare
wheel.
X Stow the collapsible spare wheel in the
emergency spare wheel well under thetrunk.
X Use the retaining screw to pierce the pro-
tective sheet and fasten the collapsible
spare wheel in place.
Inflating the collapsible spare wheel
!
Inflate the collapsible spare wheel using
the tire inflation compressor before lower-
ing the vehicle. The wheel rim could other-
wise be damaged.
344Emergency spare wheel
Wheels and tires

!Do not operate the tire inflation compres-
sor for longer than ten minutes at a time
without a break. It may otherwise overheat.
The tire inflation compressor can be oper-
ated again once it has cooled down.
X Mount the collapsible spare wheel as
described ( Ypage 335).
The collapsible spare wheel must be moun-
ted before it is inflated.
X Pull plug ?out of the housing.
X Take the filler hose out of the housing.
X Insert the yellow hose connector of the
filler hose into the guide in the housing and
push it into the fixture until the hose con-
nector engages.
X Remove the cap from the valve on the col-
lapsible spare wheel.
X Screw union nut :on the filler hose onto
the valve.
X Make sure the tire inflation compressor's
on/off switch Ais set to OFF.
X Insert plug ?into the socket of the ciga-
rette lighter or into a 12 V power socket in
your vehicle.
Observe the notes on the cigarette lighter ( Y page 262). Observe the notes on sock-
ets ( Ypage 263).
X Turn the SmartKey to position 1in the igni-
tion lock ( Ypage 139).
X Press on/off switch Aon the tire inflation
compressor to ON.
The tire inflation compressor is switched
on. The tire is inflated. The tire pressure is
shown on pressure gauge =. X
Inflate the tire to the specified tire pres-sure.
The specified tire pressure is printed on the
yellow label of the emergency spare wheel.
X When the specified tire pressure has been
reached, press on/off switch AtoOFF , on
the tire inflation compressor.
The tire inflation compressor is switchedoff.
X Turn the key to position 0in the ignition
lock.
X If the tire pressure is higher than the speci-
fied pressure, press pressure release but-ton ;until the correct tire pressure has
been reached.
X Unscrew union nut :on the filler hose
from the valve.
X Screw the cap onto the valve of the col-
lapsible spare wheel again.
Removing the filler hose
XTo remove the filler hose from the tire infla-
tion compressor, push down the rocker
switch on the hose connector and pull out
the filler hose.
X Stow plug ?and the filler hose in the lower
section of the compressor housing.
X Stow the tire inflation compressor in thevehicle.
Emergency spare wheel345
Wheels and tires
Z