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:
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 mal-functioning.
Rif 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
(
Ypage 230).
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
XMake sure that the SmartKey is in position 2
in the ignition lock (Ypage 127).
XPress the =or; button on the steering
wheel to select the Servicemenu.
XPress the9or: button to select
Tire Pressure.
XPress the abutton.
The current tire pressure of each tire is shown
in the multifunction display. If the vehicle has been parked for over
20 minutes, the
Tire pressures will be
displayed after driving a few minutesmessage appears.
After a teach-in process, the tire pressure mon-
itor automatically detects new wheels or new
sensors. As long as a clear allocation of the tire
pressure value to the individual wheels is not
possible, theTire
PressureMonitorActivedisplay message is shown instead of the tire
pressure display. The tire pressures are already
being monitored.
If an emergency spare wheel is mounted, the
system may continue to show the tire pressure
of the wheel that has been removed for a few
minutes. If this occurs, note that the value dis-
played for the position where the spare wheel is
mounted is not the same as the current tire
pressure of the emergency spare wheel.
Tire pressure monitor warning mes-
sages
If the tire pressure monitor detects a pressure
loss in one or more tires, a warning message is
shown in the multifunction display. The yellow
tire pressure warning lamp then lights up.
RIf the Correct Tire Pressuremessage
appears in the multifunction display, the tire
pressure in at least one tire is too low. The tire
pressure must be corrected when the oppor-
tunity arises.
RIf the Check Tiresmessage appears in the
multifunction display, the tire pressure in one
or more tires has dropped significantly. The
tires must be checked.
RIf the WarningTireMalfunctionmessage
appears in the multifunction display, the tire
pressure in one or more tires is dropping sud-
denly. The tires must be checked.
Observe the instructions and safety notes in the
display messages in the "Tires" section
(
Ypage 230).
If the wheel positions on the vehicle are rotated,
the tire pressures may be displayed for the
wrong positions for a short time. This is rectified after a few minutes of driving, and the tire pres-
sures are displayed for the correct positions.
310Tire pressure
Wheels and tires
Restarting the tire pressure monitor
When you restart the tire pressure monitor, all
existing warning messages are deleted and the
warning lamps go out. The monitor uses the cur-
rently set tire pressures as the reference values
for monitoring. In most cases, the tire pressure
monitor will automatically detect the new refer-
ence values after you have changed the tire
pressure. However, you can also define refer-
ence values manually as described here. The tire
pressure monitor then monitors the new tire
pressure values.
XSet the tire pressure to the value recommen-
ded for the corresponding driving situation on
the Tire and Loading Information placard on
the driver's side B-pillar (
Ypage 304).
You can find more tire pressure values for
various operating conditions in the tire pres-
sure table inside the fuel filler flap
(
Ypage 304).
XMake sure that the tire pressure is correct on
all four wheels.
XMake sure that the SmartKey is in position 2
in the ignition lock.
XPress the =or; button on the steering
wheel to select the Servicemenu.
XPress the9or: button to select
Tire Pressure.
XPress the abutton.
The multifunction display shows the current
tire pressure for the individual tires or the
Tire pressures will be displayed
after driving a few minutesmessage.
XPress the :button.
The UseCurrentPressuresasNewRef‐erenceValuesmessage appears in the mul-
tifunction display.
If you wish to confirm the restart:
XPress the abutton.
The TirePress.MonitorRestartedmes-
sage appears in the multifunction display.
After driving for a few minutes, the system
checks whether the current tire pressures are
within the specified range. The new tire pres-
sures are then accepted as reference values
and monitored.
If you wish to cancel the restart:
XPress the %button.
The tire pressure values stored at the last
restart will continue to be monitored.
Loading the vehicle
Instruction labels for tires and loads
GWARNING
Overloaded tires can overheat, causing a
blowout. Overloaded tires can also impair the steering and driving characteristics and lead
to brake failure. There is a risk of accident.
Observe the load rating of the tires. The load
rating must be at least half of the GAWR of
your vehicle. Never overload the tires by
exceeding the maximum load.
Two instruction labels on your vehicle show the maximum possible load.
(1) The Tire and Loading Information placard is on the B-pillar on the driver's side. The Tire
and Loading Information placard shows the
maximum permissible number of occu-
pants and the maximum permissible vehicle
load. It also contains details of the tire sizes
and corresponding pressures for tires
mounted at the factory.
(2) The vehicle identification plate is on the B- pillar on the driver's side. The vehicle iden-
tification plate informs you of the gross
vehicle weight rating. It is made up of the
vehicle weight, all vehicle occupants, the
fuel and the cargo. You can also find infor-
mation about the maximum gross axle
weight rating on the front and rear axle.
The maximum gross axle weight rating is
the maximum weight that can be carried by
one axle (front or rear axle). Never exceed
the maximum load or the maxi mum g
ross
axle weight rating for the front or rear axle.
:B-pillar, driver's side
Loading the vehicle311
Wheels and tires
Z
!On vehicles equipped with a tire pressure
monitor, electronic components are located
in the wheel.
Tire-mounting tools should not be used near
the valve. This could damage the electronic
components.
Only have tires changed at a qualified spe-
cialist workshop.
Always observe the instructions and safety
notes in the "Mounting a wheel" section
(
Ypage 321).
The wear patterns on the front and rear tires
differ, depending on the operating conditions.
Rotate the wheels before a clear wear pattern
has formed on the tires. Front tires typically
wear more on the shoulders and the rear tires in the center.
On vehicles that have the same size front and
rear wheels, you can rotate the wheels accord-
ing to the intervals in the tire manufacturer's
warranty book in your vehicle documents. If no
warranty book is available, the tires should be
rotated every 3,000 to 6,000 miles (5,000 to
10,000 km). Depending on tire wear, this may
be required earlier. Do not change the direction
of wheel rotation.
Clean the contact surfaces of the wheel and the
brake disc thoroughly every time a wheel is rota-
ted. Check the tire pressure and, if necessary,
restart the tire pressure loss warning system
(
Ypage 308) or the tire pressure monitor
(Ypage 311).
Direction of rotation
Tires with a specified direction of rotation have
additional benefits, e.g. if there is a risk of hydro- planing. These advantages can only be gained if
the tires are installed corresponding to the
direction of rotation.
An arrow on the sidewall of the tire indicates its
correct direction of rotation.
Storing wheels
Store wheels that are not being used in a cool,
dry and preferably dark place. Protect the tires
from oil, grease, gasoline and diesel.
Mounting a wheel
Preparing the vehicle
XStop the vehicle on solid, non-slippery and
level ground.
XApply the parking brake.
XBring the front wheels into the straight-ahead
position.
XShift the transmission to position P.
XVehicles with AIRMATIC: make sure that "nor-
mal" level is selected (Ypage 166).
XSwitch off the engine.
XRemove the SmartKey from the ignition lock.
or, on vehicles with KEYLESS‑ GO:
XOpen the driver's door.
The on-board electronics now have status 0.
This is the same as the SmartKey having been
removed.
XRemove the Start/Stop button from the igni-
tion lock (Ypage 127).
XIf included in the vehicle equipment, remove
the tire-change tool kit from the vehicle
(
Ypage 286).
XSafeguard the vehicle against rolling away.
Securing the vehicle to prevent it from
rolling away
If your vehicle is equipped with a wheel chock, it
can be found in the tire-change tool kit
(
Ypage 286).
The folding wheel chock is an additional safety
measure to prevent the vehicle from rolling
away, for example when changing a wheel.
XFold both plates upwards :.
XFold out lower plate;.
XGuide the lugs on the lower plate fully into the
openings in base plate =.
Changing a wheel321
Wheels and tires
Z
XPull connector?and the hose out of the
housing.
XRemove the cap from the valve on the col-
lapsible spare wheel.
XScrew union nut :of the hose onto the valve.
XMake sure on/off switch Aof the tire infla-
tion compressor is set to 0.
XInsert connector?into a 12 V socket
(Ypage 262) in your vehicle.
XTurn the SmartKey to position 1in the ignition
lock (Ypage 127).
XPress on/off switch Aon the tire inflation
compressor to I.
The tire inflation compressor is switched on.
The tire is inflated. The tire pressure is shown
on pressure gauge =.
XInflate the tire to the specified tire pressure.
The specified tire pressure is printed on the
yellow label of the emergency spare wheel.
XWhen the specified tire pressure has been
reached, press on/off switch Aon the elec-
tric air pump to 0.
The tire inflation compressor is switched off.
XTurn the SmartKey to position 0in the ignition
lock.
XIf the tire pressure is higher than the specified
pressure, press pressure release valve but-
ton ;until the correct tire pressure has been
reached.
XUnscrew air hose union nut :from the valve.
XScrew the cap onto the valve of the collapsi-
ble spare wheel again.
XStow connector ?and the hose in the lower
section of the tire inflation compressor.
XStow the tire inflation compressor in the vehi-
cle.
328Emergency spare wheel
Wheels and tires