2014 MERCEDES-BENZ M-Class tire pressure

Tire pressure
Tire pressure specifications
Important safety notes G
WARNING
Underinflated or overinflated tires pose the
following risks:
R the tires may burst, especially as the load
and vehicle speed increase.
R the tires may wear excessively and/or
unevenly, which may greatly impai rtire
traction.
R the driving characteristics, as well as
steering and braking, may be greatly
impaired.
There is a risk of an accident.
Follow recommended tire inflation pressures
and chec kthe pressure of all the tires
including the spare wheel:
R monthly, at least
R if the load changes
R before beginning a long journey
R under different operating conditions, e.g.
off-road driving
If necessary, correct the tire pressure.
i The specifications on the sample Tire and
Loading Information placard and tire
pressure tables are examples. Tire
pressure specifications are vehicle-specific
and may deviate from the data shown here.
The tire pressure specifications that are
valid for your vehicle can be found on the
Tire and Loading Information placard and
tire pressure table on the vehicle.
General notes The recommended tire pressures for the tires
mounted at the factory can be found on the
labels described here.
Operation with the emergency spare
wheel(Y page 436). Operation with a trailer:
the applicable
value for the rear tires is the maximum tire
pressure value stated in the table inside the
fuel filler flap.
Further information on tire pressures can be
obtained at a qualified specialist workshop.
Tire and Loading Information placard 0002
Recommended tire pressures
The Tire and Loading Information placard is
on the B-pillar on the driver's side
(Y page 409).
The Tire and Loading Information placard
contains the recommended tire pressures for
cold tires. The recommended tire pressures
are valid for the maximum permissible load
and up to the maximum permissible vehicle
speed.
Tire pressure table The tire pressure table is on the inside of the
fuel filler flap.
Example: tire pressure table for all tires permitted
for this vehicle by the factory402
Tire pressureWheels and tires

The tire pressure table contains the
recommended pressures for cold tires for
various operating conditions, i.e. differing
load and speed conditions. Example: tire pressure table with tire dimensions
If a tire size precedes a tire pressure, the tire
pressure information following is only valid
for that tire size. The load conditions "partially
laden" and "fully laden" are defined in the
table for different numbers of occupants and
amounts of luggage. The actual number of
seats may differ. Some tire pressure tables show only the rim
diameters instead of the full tire size, e.g.
R18. The rim diameter is part of the tire size
and can be found on the tire sidewall
(Y page 415).
If the tire pressures have been set to the
lower values for lighter loads and/or lower
road speeds, the pressures should be reset
to the higher values:
R if you want to drive with an increased load
and/or
R if you want to drive at higher road speeds i
The tire pressures for increased loads
and/or higher road speeds, shown in the
tire pressure table, may have a negative
effect on driving comfort.
If the tire pressure is not set correctly, this
can lead to an excessiv ebuild up of heat and
a sudde nloss of pressure.
For more information, contact a qualified
specialist workshop. Important notes on tire pressure
G
WARNING
If the tire pressure drops repeatedly, the
wheel, valve or tire may be damaged. Tire
pressure that is too low may result in a tire
blow-out. There is a risk of an accident.
R Check the tire for foreign objects.
R Check whether the wheel is losing air or the
valve is leaking.
If you are unable to rectify the damage,
contact a qualified specialist workshop. G
WARNING
If you fit unsuitable accessories onto tire
valves, the tire valves may be overloaded and
malfunction, which can cause tire pressure
loss. Due to their design, retrofitted tire
pressure monitors keep the tire valve open.
This can also result in tire pressure loss. There
is a risk of an accident.
Only screw the standard valve cap or other
valve caps approved by Mercedes-Benz for
your vehicle onto the tire valve.
Use a suitable pressure gauge to check the
tire pressure. The outer appearance of a tire
does not permit any reliable conclusion about
the tire pressure. On vehicles equipped with
the electronic tire pressure monitoring
system, the tire pressure can be checked
using the on-board computer.
The tire temperature and pressure increase
when the vehicle is in motion .This is
dependent on the driving speed and the load. Tire pressure
403Wheels and tires Z

Therefore, you should only correc
ttire
pressures when the tires are cold.
The tires are cold:
R if the vehicle has been parked without
direc tsunlight on the tires for at least three
hours and
R if the vehicle has no tbeen driven further
than 1 mile (1.6 km)
The tire temperature changes depending on
the outside temperature, the vehicle speed
and the tire load. If the tire temperature
changes by 18 ‡ (10 †), the tire pressure
changes by approximately 10 kPa (0.1 bar/
1.5 psi). Take this into accoun twhen
checking the pressure of warm tires. Only
correct the tire pressure if it is too low for the
current operating conditions. If you check the
tire pressure when the tires are warm, the
resulting value will be higher than if the tires
were cold. This is normal. Do not reduce the
tire pressure to the value specified for cold
tires. The tire pressure would otherwise be
too low.
Observe the recommended tire pressures for
cold tires:
R on the Tire and Loading Information placard
on the B-pillar on the driver's side
R in the tire pressure table on the inside of
the fuel filler flap
R printed in yellow on the rim of the
emergency/collapsible spare wheel
(depending on vehicle equipment) Underinflated or overinflated tires
Underinflation G
WARNING
Tires with pressure that is too low can
overheat and burst as a consequence. In
addition, they also suffer from excessive and/
or irregular wear, which can severely impair
the braking properties and the driving
characteristics. There is a risk of an accident. Avoid tire pressures that are too low in all the
tires, including the spare wheel.
Underinflated tires may:
R overheat, leading to tire defects
R have an adverse effect on handling
characteristics
R wear quickly and unevenly
R have an adverse effect on fuel consumption
Overinflation G
WARNING
Tires with excessively high pressure can burst
because they are damaged more easily by
road debris, potholes etc. In addition, they
also suffer from irregular wear, which can
severely impair the braking properties and the
driving characteristics. There is a risk of an
accident.
Avoid tire pressures that are too high in all the
tires, including the spare wheel.
Overinflated tires may:
R increase the braking distance
R have an adverse effect on handling
characteristics
R wear quickly and unevenly
R have an adverse effect on ride comfort
R be more susceptible to damage
Maximum tire pressures 0002
Example: maximum permissible tire
pressure 404
Tire pressureWheels and tires

Never exceed the maximum permissible tire
inflation pressure. Always observe the
recommended tire pressure for yourv
ehicle
when adjusting the tire pressure
(Y page 402).
i The actual values for tires are vehicle-
specific and may deviate from the values in
the illustration. Checking the tire pressures
Important safety notes Observe the notes on tire pressure
(Y
page 402).
Information on air pressure for the tires on
your vehicle can be found:
R on the vehicle's Tire and Loading
Information placard loading information
table on the B-pillar (Y page 409)
R on the tire pressure label on the fuel filler
flap
R in the "Tire pressure" section
R under "Tire pressure" (Y page 402)
Checking tire pressures manually To determine and set the correct tire
pressure, 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 with
the recommended value on the Tire and
Loading Information placard (Y page 402).
X If the tire pressure is too low, increase it to
the recommended value.
X If the tire pressure is too high, release air
by pressing down the metal pin in the valve.
Use the tip of a pen, for example. Then,
chec kthe tire pressure again using the tire
pressure gauge.
X Screw the valve cap onto the valve.
X Repeatt hese steps for the other tires. Tire pressure loss warning system
(Canada only)
General notes While the vehicle is in motion, the tire
pressure 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 appearint
he multifunction
display.
You can recognize the tire pressure loss
warning by the Run Flat Indicator Active Press 'OK' to Restart message
which appears in the Serv. menu of the
multifunction display. Information on the
message display can be found in the
"Restarting the tire pressure loss warning
system" section (Y page 406).
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 402).
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. Tire pressure
405Wheels and tires Z

R
you adop tavery sporty driving style
(cornering at high speeds or driving with
high rates of acceleration).
R you are towing a very heavy or large trailer.
R you are driving with a heavy load (in the
vehicle or on the roof).
Restarting the tire pressure loss
warning system Restart the tire pressure loss warning system
if you have:
R
changed the tire pressure
R changed the wheels or tires
R mounted new wheels or tires
X Before restarting, make sure that the tire
pressures are set properly on all four tires
for the respective operating conditions.
The recommended tire pressures can be
found on the Tire and Loading Information
placard on the B-pillar on the driver's side
or the tire pressure table on the fuel filler
flap.
The tire pressure loss warning system can
only give reliable warnings if you have set
the correct tire pressure. If an incorrect tire
pressure is set, these incorrect values will
be monitored.
X Also observe the notes in the section on tire
pressures (Y page 402).
X Make sure that the SmartKey is in position
2in the ignitio nlock (Y page 157).
X Press the 0002or0005 button on the
steering wheel to select the Serv. menu.
X Press the 0003or0004 button to select
Tire Pressure .
X Press the 000Bbutton.
The Run Flat Indicator Active Press 'OK' to Restart message
appears in the multifunction display. If you wish to confirm the restart:
X
Press the 000Bbutton.
The Tire Pressure Now OK? message
appears in the multifunction display.
X Press the 0003or0004 button to select
Yes .
X Press the 000Bbutton.
The Run Flat Indicator Restarted message appears in the multifunction
display.
After a teach-in period, the tire pressure
loss warning system will monitor the set
tire pressures of all four tires.
If you wish to cancel the restart:
X Press the 0007button.
or
X If the Tire Pressure Now OK? message
appears, use the 0003or0004 button to
select Cancel .
X Press the 000Bbutton.
The tire pressure values stored at the last
restart will continue to be monitored. Tire Pressure Monitor
General notes If a tire pressure monitor is installed, the
vehicle's wheels have sensors that monitor
the tire pressures in all four tires. The tire
pressure monitor warns you if the pressure
drops in one or more of the tires. The tire
pressure monitor only functions if the correct
sensors are installed on all wheels.
Information on tire pressures is displayed in
the multifunction display .After a few minutes
of driving, the current tire pressure of each
tire is show nintheService menu of the
multifunction display. 406
Tire pressureWheels and tires

Example: current tire pressure display
For informatio
nonthe message display, refer
to the "Checking the tire pressure
electronically" section (Y page 408).
Important safety notes G
WARNING
Each tire, including the spare (if provided),
should be checked at least once a month
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
pressure 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 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
pressure telltale when one or more of your
tires are significantly underinflated.
Accordingly, when the low tire pressure
telltale illuminates, you should stop and check
your tires as soon as possible, and inflate
them to the proper pressure. Driving on a
significantly underinflated 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 responsibility to maintain correct tire
pressure, even if underinflation has not
reached the level to trigger illumination of the
TPMS low tire pressure telltale. USA only:
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
vehicle is started as long as the malfunction
exists.
When the malfunction indicator is illuminated,
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
incompatible 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 402). Note that the correct tire
pressure 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 adjusting the pressure of the
cold tires (Y page 409). The current
pressures are saved as new reference values.
As a result, a warning message will appearif
the tire pressure 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 402).
The tire pressure monitor is not able to warn
you of a sudden loss of pressure, e.g .ifthe Tire pressure
407Wheels and tires Z

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
warning lamp in the instrument cluster for
indicating a pressure loss or malfunction.
Whether the warning lamp flashes or lights up
indicates whether a tire pressure is too low or
the tire pressure monitor is malfunctioning:
R if the warning lamp is li tcontinuously, the
tire pressure on one or more tires is
significantly 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.
i In addition to the warning lamp, a
message appears in the multifunction
display.
Further information can be found on
(Y page 310).
If the tire pressure monitor is malfunctioning,
it may take more than ten minutes for the tire
pressure warning lamp to inform you of 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
measured 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
transmitting equipment (e.g. radio
headphones, two-way radios) that may be
being operated in or near the vehicle. Checking the tire pressure
electronically X
Make sure that the SmartKey is in position
2(Y page 157) in the ignition lock.
X Press the 0002or0005 button on the
steering wheel to select the Service menu.
X Press the 0003or0004 button to select
Tire Pressure .
X Press the 000Bbutton.
The current tire pressure of each tire is
shown in the multifunction display.
If the vehicle has been parked for longer than
20 minutes, the Tire pressure will be displayed after driving a few
minutes message appears.
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 Active display message is shown
instead of the tire pressure display .The tire
pressures are already being monitored.
i 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 displayed 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
messages If the tire pressure monitor detects a pressure
loss in one or more tires, a warning message
is shown in the multifunction display and the
yellow tire pressure monitor warning lamp
comes on.
R If the Correct Tire Pressure message
appears in the multifunction display, the
tire pressure in at least one tire is too low 408
Tire pressureWheels and tires

and must be corrected at the next
opportunity.
R If the Check Tires message appears in the
multifunction display, the tire pressure in
one or more tires has dropped significantly
and the tires must be checked.
R If the Tire Malfunction appears in the
multifunction display, the tire pressure in
one or more tires has dropped suddenly
and the tires must be checked.
i If the wheel positions on the vehicle are
rotated, the tire pressure smay 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 correct positions.
Restarting the tire pressure monitor When you restar
tthe 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
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 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
recommended for the corresponding
driving situation on the Tire and Loading
Information placard on the driver's side
B-pillar (Y page 402).
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 174).
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 0002or0005 button on the
steering wheel to select the Service menu.
X Press the 0003or0004 button to select
Tire Pressure .
X Press the 000Bbutton.
The multifunction display shows the
current tire pressure for the individual tires
or the Tire pressure will be displayed after driving a few
minutes message.
X Press the 0004button.
The Use Current Pressures as New Reference Values message appears in
the multifunction display.
If you wish to confirm the restart:
X Press the 000Bbutton.
The Tire Press. Monitor Restarted message 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
pressures are then accepted as reference
values and monitored.
If you wish to cancel the restart:
X Press the 0007button.
The tire pressure values stored at the last
restart will continue to be monitored. 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. Loading the vehicle
409Wheels and tires Z