Checking the tire pressures
Important safety notes Observe the notes on tire pressure
(Y page 348).
Information on air pressure for the tires on
your vehicle can be found:
R on the vehicle's Tire and Loading Informa-
tion placard on the B-pillar
R on the tire pressure label on the fuel filler
flap
R in the "Tire pressure" section
Checking tire pressures manually To determine and set the correct tire pres-
sure, proceed as follows:
X Remove the valve cap of the tire that is to
be checked.
X Press the tire pressure gauge securely onto
the valve.
X Read the tire pressure and compare it to
the recommended value on the Tire and
Loading Information placard or the tire
pressure table (Y page 348).
X If the tire pressure is too low, increase the
tire pressure to the recommended value.
X If the tire pressure is too high, release air.
To do so, press down the metal pin in the
valve, using the tip of a pen for example.
Then check the tire pressure again using
the tire pressure checker.
X Screw the valve cap onto the valve.
X Repeat these steps for the other tires. Tire pressure loss warning system
(Canada only)
General notes While the vehicle is in motion, the tire pres-
sure loss warning system monitors the set
tire pressure using the rotational speed of the wheels. This enables the system to detect
significant pressure loss in a tire. If the speed of rotation of a wheel changes as a result of a
loss of pressure, a corresponding warning
message will appear in the multifunction dis- play.
You can recognize the tire pressure loss warn-
ing by the Run Flat Indicator Active
Run Flat Indicator Active
Press 'OK' to Restart Press 'OK' to Restart message which
appears in the Serv.
Serv.menu of the multifunc-
tion display. Information on the message dis-
play can be found in the "Restarting the tire
pressure loss warning system" section
(Y page 352).
Important safety notes The tire pressure warning system does not
warn you of an incorrectly set tire pressure.
Observe the notes on the recommended tire
pressure (Y
page 348).
The tire pressure loss warning does not
replace the need to regularly check the tire
pressure. An even loss of pressure on several tires at the same time cannot be detected by
the tire pressure loss warning system.
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 function of the tire pressure loss warning system is limited or delayed if:
R snow chains are mounted on your vehicle's
tires.
R road conditions are wintry.
R you are driving on sand or gravel.
R you adopt a very sporty driving style (cor-
nering at high speeds or driving with high
rates of acceleration).
R you are driving with a heavy load (in the
vehicle or on the roof). Tire pressure
351Wheels and tires Z
weeks when cold and inflated to the pressure
recommended by the vehicle manufacturer
on the Tire and Loading Information placard
on the driver's door B-pillar or the tire pres-
sure label on the inside of the fuel filler flap. If
your vehicle has tires of a different size than
the size indicated on the Tire and Loading
Information placard or, if available, the tire
pressure label, you should determine the
proper tire pressure for those tires.
As an added safety feature, your vehicle has
been equipped with a tire pressure monitoring system (TPMS) that illuminates a low tire pres-
sure telltale when one or more of your tires
are significantly underinflated. Accordingly,
when the low tire pressure telltale lights up,
you should stop and check your tires as soon
as possible, and inflate them to the proper
pressure. Driving on a significantly underin-
flated tire causes the tire to overheat and can
lead to tire failure.
Underinflation also reduces fuel efficiency
and tire tread life, and may affect the vehicle's handling and stopping ability. Please note that the TPMS is not a substitute for proper tire
maintenance, and it is the driver's responsi-
bility to maintain correct tire pressure, even if
underinflation has not reached the level to
trigger illumination of the TPMS low tire pres-
sure telltale.
Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate when
the system is not operating properly. The
TPMS malfunction indicator is combined with
the low tire pressure telltale. When the sys-
tem 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 malfunction
exists. When the malfunction indicator is illu-
minated, the system may not be able to detect
or signal low tire pressure as intended.
TPMS malfunctions may occur for a variety of reasons, including the installation of incom-
patible replacement or alternate tires or
wheels on the vehicle that prevent the TPMS from functioning properly. Always check the
TPMS malfunction telltale after replacing one
or more tires or wheels on your vehicle to
ensure that the replacement or alternate Tires and wheels allow the TPMS to continue to
function properly.
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 348). 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 355). 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 348).
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. Tire pressure
353Wheels and tires Z
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.
X Set the tire pressure to the value recom-
mended for the corresponding driving sit-
uation on the Tire and Loading Information
placard on the driver's side
B-pillar (Y page 348).
Additional tire pressure values for different loads can also be found on the tire pressure
table on the inside of the fuel filler flap
(Y page 348).
X Make sure that the tire pressure is correct
on all four wheels.
X Make sure that the SmartKey is in position
2 in the ignition lock.
X Press the =or; button on the steer-
ing wheel to select the Service
Service menu.
X Press the 9or: button to select
Tire Pressure Tire Pressure .
X Press the abutton.
The multifunction display shows the cur-
rent tire pressure for the individual tires or
the Tire
Tire pressure pressure will
willbe
bedisplayed
displayed
after driving a few minutes
after driving a few minutes mes-
sage.
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 Tire Press. Monitor Restarted
Tire Press. Monitor Restarted
message appears in the multifunction dis-
play. After driving for a few minutes, the system
checks whether the current tire pressures
are within the specified range. The new tire
pressures are then accepted as reference
values and monitored.
If you wish to cancel the restart:
X Press the %button.
The tire pressure values stored at the last
restart will continue to be monitored.
Radio type approval for the tire pres-
sure monitor Country Radio type approval number
USA FCC ID: MRXMW2433A
FCC ID: MRXGG4
FCC ID: MRXMC34MA4
Canada IC: 2546A-MW2433A
IC: 2546A-GG4
IC: 2546A-MC34MA4
Loading the vehicle
Instruction labels for tires and loads
G
WARNING
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 occupants and the maximum permis-
sible vehicle load. It also contains details Loading the vehicle
355Wheels and tires Z