Checking the tire pressure electroni-
cally
XMake sure that the SmartKey is in position2 in the ignition lock (
Ypage 153).
XUse ò on the steering wheel to call up
the list of menus.
XPress 9or: on the steering wheel
to select the Service
menu.
XPress theabutton.
XPress 9or: to select Tire Pres‐
sure.
XPress the abutton.
The current tire pressure of each tire is
shown in the multifunction display.
If the vehicle was parked for longer than
20 minutes, the following message appears:
Tire pressure will be displayed
after driving a few minutes.
After a teach-in process, the tire pressure
monitor 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, the Tire Pressure
Monitor Activemessage is shown instead
of the tire pressure display. The tire pressures are already being monitored.
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 yel- low tire pressure warning lamp then lights up.
RIf the Please Correct Tire Pressure
message appears in the multifunction dis-
play, the tire pressure in at least one tire is
too low. The tire pressure must be correc-
ted when the opportunity arises.
RIf theCheckTiresmessage appears in the
multifunction display, the tire pressure in at
least one tire has dropped significantly. The
tires must be checked.
RIf the Warning Tire Malfunctionmes-
sage appears in the multifunction display, the tire pressure in at least one tire has
dropped suddenly. The tires must be
checked.
Observe the instructions and safety notes in
the display messages in the "Tires" section
(
Ypage 285).
If the wheel positions on the vehicle are rota-
ted, 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 pressures are displayed for the cor-
rect positions.
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 currently set tire pressures as the refer-
ence 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 define reference values manually as
described here. The tire pressure monitor
then monitors the new tire pressure values.
XSet the tire pressure to the value recom-
mended for the corresponding driving sit-
uation on the Tire and Loading Informationplacard on the driver's side
B-pillar (
Ypage 377).
You can find more tire pressure values for
various operating conditions in the tire
pressure table inside the fuel filler flap
(
Ypage 377).
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 (
Ypage 153).
XUse ò on the steering wheel to call up
the list of menus.
XPress 9or: on the steering wheel
to select the Service
menu.
XPress theabutton.
XPress 9or: to select Tire Pres‐
sure.
Tire pressure383
Wheels and tires
Z
Tire labeling
Overview
:Uniform Tire Quality Grading Standard
(
Ypage 393)
;DOT, Tire Identification Number
(
Ypage 392)
=Maximum tire load (Ypage 391)
?Maximum tire pressure (Ypage 380)
AManufacturer
BTire material (Ypage 392)
CTire size designation, load-bearing capa-
city and speed rating (
Ypage 389)
DLoad index (Ypage 391)
ETire name
The markings described above are on the tire
in addition to the tire name (sales designa-
tion) and the manufacturer's name.
iTire data is vehicle-specific and may devi-
ate 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
;Nominal aspect ratio in %
=Tire code
?Rim diameter
ALoad bearing index
BSpeed rating
General: depending on the manufacturer's
standards, the size imprinted in the tire wall
may not contain any letters or may contain
one letter that precedes 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: these are
passenger vehicle tires according to U.S.
manufacturing standards.
If "LT" precedes the size description: these
are light truck tires according to U.S. manu-
facturing standards.
If "T" precedes the size description: compactemergency wheels with high tire pressure
that are only designed for temporary use in an
emergency.
Tire width: tire width:shows the nominal
tire width in millimeters.
Height-width ratio: aspect ratio;is the
size ratio between the tire height and tire
width and is shown in percent. The aspect
All about wheels an d tires389
Wheels and tires
Z