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 a spare wheel is installed, the system may
continue to show the tire pressure of the wheel
that has been removed for a few minutes. Please
note that in this case, the value displayed for the
replaced wheel does not indicate the current
tire pressure of the 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
htire 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 at
least one tire has dropped significantly. The
tires must be checked.
RIf the Caution - Tire Malfunc.message
appears in the multifunction display, the tire
pressure in at least one tire has dropped sud-
denly. The tires must be checked.
Be sure to observe the instructions and safety
notes in the display messages in the "Tires" sec-
tion (
Ypage 187).
If the position of the wheels on the vehicle is
changed, the tire pressure may be displayed in
the wrong positions for a short time. This is rec- tified after a few minutes of driving, and the tire
pressures are displayed for the correct posi-
tions.
Restarting the tire pressure monitor
When you restart the tire pressure monitor, all
existing warning messages are deleted and the
h warning lamp goes out. The monitor uses
the currently set tire pressures as the reference
values for monitoring. In most cases, the tire pressure monitor will automatically detect the
new reference values after you have changed
the tire pressure. However, you can also set ref-
erence 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 B-pillar on the driver's side.
You can find more tire pressures for various
operating conditions in the tire pressure table
inside the filler flap.
Observe the information on tire pressure
when doing so (
Ypage 260).
XMake sure that the tire pressure is correct on
all four wheels.
XEnsure that the SmartKey is in position 2in
the ignition lock.
XPress the =or; button on the steering
wheel to select the Serv.menu.
XPress the9or: button to select
Tire Pressure.
XPress the abutton.
The multifunction display shows the current
tire pressure for each tire or the Tire pres‐
surewillbedisplayedafterdrivinga few minutesmessage appears.
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.
Tire pressure265
Wheels and tires
Z
in combination, can cause excessive heat
build-up and possible tire failure.
The temperature grades are A (the highest), B,
and C, representing the tire's resistance to the
generation of heat and its ability to dissipate
heat when tested under controlled conditions
on a specified indoor laboratory test wheel. Sus-
tained high temperature can cause the material
of the tire to degenerate and reduce tire life, and
excessive temperature can lead to sudden tire
failure. The grade C corresponds to a level of
performance which all passenger car tires must
meet under the Federal Motor Vehicle Safety
Standard No. 109. Grades B and A represent
higher levels of performance on the laboratory
test wheel than the minimum required by law.
Tire labeling
Overview of tire labeling
:Uniform Tire Quality Grading Standard
(Ypage 273)
;DOT, Tire Identification Number
(Ypage 272)
=Maximum tire load (Ypage 272)
?Manufacturer
AMaximum tire pressure (Ypage 262)
BTire material (Ypage 273)
CTire size designation, load-bearing capacity
and speed rating (Ypage 270)
DLoad index (Ypage 272)
ETire name The markings described above are on the tire in
addition to the tire name (sales designation) and
the manufacturer's name.
iTire data is vehicle-specific and may deviate
from the data in the example.
Tire size designation, load-bearing
capacity and speed rating
GWARNING
Exceeding the stated tire load-bearing capa-
city and the approved maximum speed could
lead to tire damage or the tire bursting. There is a risk of accident.
Therefore, only use tire types and sizes
approved for your vehicle model. Observe the
tire load rating and speed rating required for
your vehicle.
:Tire width
;Height-width ratio in percentage
=Tire code
?Rim diameter
ALoad bearing index
BSpeed rating
General: depending on the manufacturer's
standards, a letter is imprinted into the tire wall before the size description.
If there is no letter preceding the size descrip-
tion (as shown above): these are passenger
vehicle tires according to European manufac-
turing standards.
If "P" precedes the size description: passenger
vehicle tires according to U.S. manufacturing
standards.
If "P" precedes the size description: light truck
tires according to U.S. manufacturing stand-
ards.
270All about wheels and tires
Wheels and tires
PSI (pounds per square inch)
A standard unit of measure for tire pressure.
Aspect ratio
Relationship between tire height and tire width
in percent.
Tire pressure
This is pressure inside the tire applying an out-
ward force to each square inch of the tire's sur-
face. The tire pressure is specified in pounds per
square inch (psi), in kilopascals (kPa) or in bar.
The tire pressure should only be corrected when
the tires are cold.
Cold tire pressure
The tires are cold:
Rif the vehicle has been parked with the tires
out of direct sunlight for at least three hours
and
Rif the vehicle has not been driven further than
1 mile (1.6 km)
Tread
The part of the tire that comes into contact with
the road.
Bead
The tire bead ensures that the tire sits securely
on the wheel. There are several steel wires in the
bead to prevent the tire from coming loose fromthe wheel rim.
Sidewall
The part of the tire between the tread and the
bead.
Weight of optional extras
The combined weight of those optional extras
that weigh more than the replaced standard
parts and more than 2.3 kg (5 lbs). These
optional extras, such as high-performance
brakes, level control, a roof rack or a high-per-
formance battery, are not included in the curb
weight and the weight of the accessories.
TIN (Tire Identification Number)
This is a unique identifier which can be used by
a tire manufacturer to identify tires, for example
for a product recall, and thus identify the pur-
chasers. The TIN is made up of the manufactur-
er's identity code, tire size, tire type code and
the manufacturing date.
Load bearing index
The load bearing index (also load index) is a code
that contains the maximum load bearing capa-
city of a tire.
Traction
Traction is the result of friction between the tires
and the road surface.
TWR (Tongue Weight Rating)
The TWR specifies the maximum permissible
weight that the ball coupling of the trailer tow
hitch can support.
Treadwear indicators
Narrow bars (tread wear bars) that are distrib-
uted over the tire tread. If the tire tread is level
with the bars, the wear limit of áin (1.6 mm)
has been reached.
Occupant distribution
The distribution of occupants in a vehicle at their
designated seating positions.
Total load limit
Nominal load and luggage load plus 68 kg
(150 lbs) multiplied by the number of seats in
the vehicle.
Changing a wheel
Flat tire
You can find information on what to do in the
event of a flat tire in the "Breakdown assistance"
section (
Ypage 246).
Rotating the wheels
GWARNING
Interchanging the front and rear wheels may
severely impair the driving characteristics if
the wheels or tires have different dimensions. The wheel brakes or suspension components
may also be damaged. There is a risk of acci-
dent.
Rotate front and rear wheels only if the wheels and tires are of the same dimensions.
Changing a wheel275
Wheels and tires
Z