2012 MERCEDES-BENZ B-CLASS tire pressure

Tires
Display messages Possible causes/consequences and
M SolutionsCheck
Tire Pressure Soon The tire pressure loss warning system has detected a significant
loss in pressure.
A warning tone also sounds.
G WARNING
With tire pressures which are too low, there is a risk of the
following hazards:
R they may burst, especially as the load and vehicle speed
increase.
R they may wear
excessively and/or unevenly, which may greatly
impair tire traction.
R the driving characteristics, as well as steering and braking, may
be greatly impaired.
There is a risk of an accident.
X Stop the vehicle without making any sudden steering or braking
maneuvers. Pay attention

to the traffic conditions as you do so.
X Secure the vehicle against rolling away ( Y page 149).
X If there is a flat tire, inspect the tires ( Y page 281).
X Check the tire pressures and, if necessary, correct the tire
pressure.
X Restart the tire pressure loss warning system when the tire
pressure is correct (Y page 305). Check Tire Pressure
Then Restart Run
Flat Indicator The tire pressure loss warning system generated a display
message and has not been restarted since.
X
Set the correct tire pressure in all four tires.
X Restart the tire pressure loss warning system ( Y page 305).Run Flat Indicator
Inoperative The tire pressure loss warning system is faulty.
X
Visit a qualified specialist workshop. Display messages
219
On-board computer and displays Z
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X
Open the tailgate.
X Lift the cargo compartment floor up
(Y page 246).
i Towing eye ; is located under tire
inflation compressor :.
Vehicles with a tire-change tool kit X
Open the tailgate.
X Lift the cargo compartment floor up
(Y page 246).
X Remove the tire-change tool kit.
The tire-change tool kit contains:
R Jack
R Lug wrench
R One pair of gloves
R Folding wheel chock Flat tire
Preparing the vehicle
Your vehicle may be equipped with:
R MOExtended tires (tires with run-flat
properties) ( Y page 281)
Vehicle preparation is not necessary on
vehicles with MOExtended tires.
R a TIREFIT kit (Y page 280)
Information on changing/mounting a wheel
(Y page 319).
X Stop the vehicle on solid, non-slippery and
level ground, as far away as possible from
traffic.
X Switch on the hazard warning lamps.
X Secure the vehicle against rolling away
(Y page 149).
X If possible, bring the front wheels into the
straight-ahead position.
X Switch off the engine.
X Remove the SmartKey from the ignition
lock. X
All occupants must get out of the vehicle.
Make sure that
they are not endangered as
they do so.
X Make sure that no one is near the danger
area while a wheel is being changed.
Anyone who is not directly assisting in the
wheel change should, for example, stand
behind the barrier.
X Get out of the vehicle. Pay attention to
traffic conditions when doing so.
X Close the driver's door.
i Vehicles equipped with

MOExtended tires
are not equipped with a TIREFIT kit at the
factory. It is therefore recommended that
you additionally equip your vehicle with a
TIREFIT kit if you mount tires that do not
feature run-flat properties, e.g. winter tires.
A TIREFIT kit can be obtained from a
qualified specialist workshop. MOExtended tires (tires with run-flat
properties)
General notes With MOExtended tires (tires with run flat
characteristics), you can continue to drive
your vehicle even if there is a total loss of
pressure in one or more tires. The affected
tire must
not

show any clearly visible damage.
You can recognize MOExtended tires by the
MOExtended marking which appears on the
sidewall of the tire. You will find this marking
next to the tire size designation, the load-
bearing capacity and the speed index
(Y page 313).
MOExtended tires may only be used in
conjunction with an active tire pressure loss
warning system.
If the pressure loss warning message
appears in the multifunction display:
R Observe the instructions in the display
messages ( Y page 219).
R Check the tire for damage.
R If driving on, observe the following notes. Flat tire
281
Breakdown assistance
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The maximum driving distance is
approximately 50 miles (80 km) when the
vehicle is partially laden and approximately
18 miles (30 km) when the vehicle is fully
laden.
In addition to the vehicle load, the driving
distance possible depends upon:
R Speed
R Road condition
R Outside temperature
The driving
distance possible in run-flat mode
may be reduced by extreme driving
conditions/maneuvers, or it can be increased
through a moderate style of driving.
The maximum permissible distance which
can be driven in run-flat mode is counted from
the moment the tire pressure loss warning
appears in the multifunction display.
You must not exceed a maximum speed of
50 mph (80 km/h).
i When replacing one or all tires, make sure
that you use only tires:
R of the size specified for the vehicle and
R marked "MOExtended"
If a tire has gone flat and cannot be
replaced with a MOExtended tire, a
standard tire may be used as a temporary
measure. Make sure that you use the
proper size and type (summer or winter
tire).
i Vehicles equipped with MOExtended tires
are not equipped with a TIREFIT kit at the
factory. It is therefore recommended that
you additionally equip your vehicle with a
TIREFIT kit if you mount tires that do not
feature run-flat properties, e.g. winter tires.
A TIREFIT kit can be obtained from a
qualified specialist workshop.
Important safety notes G
WARNING
When driving in emergency mode, the driving
characteristics deteriorate, e.g. when cornering, accelerating quickly and when
braking. There is a risk of an accident.
Do not exceed the stated maximum speed.
Avoid abrupt
steering
and driving maneuvers,
and driving over obstacles (curbs, potholes,
off-road). This applies in particular to a laden
vehicle.
Stop driving in emergency mode if:
R you hear banging noises.
R the vehicle starts to shake.
R you see smoke and smell rubber.
R ESP ®
is intervening constantly.
R there are tears in the sidewalls of the tire.
After driving in emergency mode, have the
wheel rims checked at a qualified specialist
workshop with regard to their further use. The
defective tire must be replaced in every case. TIREFIT kit
Important safety notes G
WARNING
In the following situations, the tire sealant is
unable to provide sufficient breakdown
assistance, as it is unable to seal the tire
properly:
R there are cuts

or punctures in the tire larger
than those mentioned above.
R the wheel rim is damaged.
R you have driven at very low tire pressures
or on a flat tire.
There is a risk of an accident.
Do not drive any further. Contact a qualified
specialist workshop. G
WARNING
The tire sealant is harmful and causes
irritation. It must not come into contact with
your skin, eyes or clothing or be swallowed.
Do not inhale

TIREFIT fumes. Keep tire sealant
away from children. There is a risk of injury. 282
Flat tire
Breakdown assistance
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X
Press on/off switch ? on the tire inflation
compressor to ON.
The tire inflation compressor is switched
on. The tire is inflated.
i First, tire sealant is pumped into the tire.
The pressure can briefly rise to
approximately 500 kPa (5 bar/73 psi).
Do not switch off the tire inflation
compressor during this phase.
X Let the tire inflation compressor run for a
maximum of ten minutes. The tire should
then have attained a pressure of at least
200 kPa (2.0 bar/29 psi).
! Do not operate the tire inflation
compressor for longer than ten minutes at
a time without a break. It may otherwise
overheat.
The tire inflation compressor can be
operated again once it has cooled down.
If a pressure

of 200 kPa (2.0 bar/29 psi) has
been attained after a maximum of after ten
minutes, see ( Y page 284).
If a pressure of 200 kPa (2.0 bar/29 psi) has
not been attained after a maximum of ten
minutes, see ( Y page 284).
i If tire sealant leaks out, allow it to dry. It
can then be removed like a layer of film.
If your clothes are soiled with tire sealant,
have them cleaned with perchloroethylene
at a dry cleaner as soon as possible.
Tire pressure not reached If a pressure of 200 kPa (
2.0 bar
/29 psi) has
not been achieved after ten minutes:
X Switch off the tire inflation compressor.
X Unscrew the filler hose from the valve of
the faulty tire.
X Very slowly drive forwards or reverse
approximately 30 ft (10 m).
X Pump up the tire again.
After a maximum of ten minutes, the tire
pressure

must be
at least 200 kPa (2.0 bar/
29 psi). G
WARNING
If the required tire pressure is not reached
after the specified time, the tire is too badly
damaged. The tire sealant cannot repair the
tire in this

instance. Damaged tires and a tire
pressure that is too low can significantly
impair the vehicle's braking and driving
characteristics. There is a risk of accident.
Do not continue driving. Contact a qualified
specialist workshop.
Tire pressure reached G
WARNING
A tire temporarily sealed with tire sealant
impairs the driving characteristics and is not
suitable for higher speeds. There is a risk of
accident.
You should therefore adapt your driving style
accordingly and drive

carefully. Do not exceed
the specified maximum speed with a tire that
has been repaired using tire sealant.
! After use, excess tire sealant may run out
of the filler hose. This could cause stains.
Therefore, place the filler hose in the plastic
bag that contained the TIREFIT kit. H
Environmental note
Have the used tire sealant bottle disposed of
professionally, e.g. at a qualified specialist
workshop.
If a tire

pressure of 200 kPa (2.0 bar/29 psi)
has been achieved after ten minutes:
X Switch off the tire inflation compressor.
X Unscrew the filler hose from the valve of
the faulty tire.
X Stow the tire sealant bottle and the tire
inflation compressor.
X Pull away immediately.
The maximum speed for a tire sealed with tire
sealant is 50 mph (

80 km/h). The upper part
of the TIREFIT sticker must be affixed to the
instrument cluster in the driver's field of
vision. 284
Flat tire
Breakdown assistance
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X
Stop after driving for approximately ten
minutes and check the tire pressure with
the tire inflation compressor.
The tire pressure must now be at least
130 kPa (1.3 bar/19 psi). G
WARNING
If the required tire pressure is not reached
after driving for a short period, the tire is too
badly damaged. The
tire sealant cannot repair
the tire in this instance. Damaged tires and a
tire pressure that is too low can significantly
impair the vehicle's braking and driving
characteristics. There is a risk of accident.
Do not continue driving. Contact a qualified
specialist workshop.
X Correct the tire pressure if it is still at least
130 kPa (1.3 bar/19 psi) (for the values,
see the Tire and Loading Information
placard on the driver's side B-pillar or tire
pressure table on the fuel filler flap).
X To increase the tire pressure: switch on
the tire inflation compressor. X
To reduce the tire pressure: depress
pressure release button : next to
pressure gauge ;. X
To remove the tire sealant bottle from the
tire inflation compressor, press together
the locking tabs on the yellow cap.
X Pull the tire sealant bottle out of the tire
inflation compressor.
The filler hose

remains attached to the tire
sealant bottle.
X Stow the tire sealant bottle and the tire
inflation compressor.
X Drive to the nearest qualified specialist
workshop and have

the tire changed there.
X Have the tire sealant bottle and the filler
hose replaced as soon as possible at a
qualified specialist workshop.
X Have the tire sealant bottle replaced every
four years at a qualified specialist
workshop. Battery (vehicle)
Important safety notes
Special tools and expert knowledge are
required when working on the battery, e.g.
removal and installing. You should therefore
have all work

involving the battery carried out
at a qualified specialist workshop. G
WARNING
Work carried out incorrectly on the battery
can, for example, lead to a short circuit and
damage your vehicle's

electronic system. This
can disrupt driving safety systems such as
ABS (anti-lock braking system) or ESP ®
(Electronic Stability Program). Battery (vehicle)
285
Breakdown assistance
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Useful information ............................
298
Important safety notes ....................298
Operation ........................................... 298
Winter operation ............................... 300
Tire pressure ..................................... 301
Loading the vehicle ..........................306
Maximum load rating .......................310
Uniform Tire Quality Grading
Standards .......................................... 311
Tire labeling ....................................... 312
Definition of terms for tires and
loading ............................................... 316
Changing a wheel ............................. 319
Wheel and tire combinations ...........323
Emergency spare wheel ...................325 297Wheels and tires
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Useful information
i This Operator's Manual describes all
models and all standard and optional
equipment of your vehicle available at the
time of publication of the Operator's
Manual. Country-specific differences are
possible. Please note
that your vehicle may
not be equipped with all features
described. This also applies to safety-
related systems and functions.
i Read the information on qualified
specialist workshops: ( Y page 24).Important safety notes
G
WARNING
If wheels and tires of the wrong size are used,
the wheel brakes or suspension components
may be damaged. There is a risk of an
accident.
Always replace wheels and tires with those
that fulfill the specifications of the original
part.
When replacing wheels,

make sure to use the
correct:
R designation
R model
When replacing tires, make sure to use the
correct:
R designation
R manufacturer
R model G
WARNING
A flat tire severely impairs the driving,
steering and braking characteristics of the
vehicle. There is a risk of accident.
Tires without run-flat characteristics:
R do not drive with a flat tire.
R immediately replace the flat tire with your
emergency spare wheel or spare wheel, or
consult a qualified specialist workshop. Tires with run-flat characteristics:
R
pay attention to the information and
warning notices on

MOExtended tires (tires
with run-flat characteristics).
Accessories that are not approved for your
vehicle by Mercedes-Benz or are not being
used correctly can impair the operating
safety.
Before purchasing and using non-approved
accessories, visit a qualified specialist
workshop and inquire about:
R suitability
R legal stipulations
R factory recommendations
Information on dimensions and types of
wheels and tires for your vehicle can be found
(Y page 323).
Information on air pressure for the tires on
your vehicle can be found:
R on the vehicle's Tire and Loading
Information placard on the B-pillar
R on the tire pressure label on the fuel filler
flap
R under "Tire pressure"
i Further information on wheels and tires
can be obtained at any qualified specialist
workshop. Operation
Information on driving
R If the vehicle is heavily loaded, check the
tire pressures and correct them if
necessary.
R While driving, pay attention to vibrations,
noises and unusual handling
characteristics, e.g. pulling to one side.
This may indicate that the wheels or tires
are damaged. If you suspect that a tire is
defective, reduce your speed immediately.
Stop the vehicle as soon as possible to
check the wheels and tires for damage.
Hidden tire damage could also be causing298
Operation
Wheels and tires
ProCarManuals.com

the unusual handling characteristics. If you
find no signs of damage, have the wheels
and tires checked at a qualified specialist
workshop.
R When parking your
vehicle, make sure that
the tires do not get deformed by the curb
or other obstacles. If it is necessary to drive
over curbs, speed humps or similar
elevations, try to do so slowly and at an
obtuse angle. Otherwise, the tires,
particularly the sidewalls, may be
damaged. Regular checking of wheels and tires
G
WARNING
Damaged tires can cause tire inflation
pressure loss. As a result, you could lose
control of your vehicle. There is a risk of
accident.
Check the tires regularly for signs of damage
and replace any damaged tires immediately.
Regularly check the wheels and tires of your
vehicle for damage

at least once a month, as
well as after driving off-road or on rough
roads. Damaged wheels can cause a loss of
tire pressure. Pay particular attention to
damage such as:
R cuts in the tires
R punctures
R tears in the tires
R bulges on tires
R deformation or severe corrosion on wheels
Regularly check the tire tread depth and the
condition of the tread across the whole width
of the tire (Y page 299). If necessary, turn
the front wheels to full lock in order to inspect
the inner side of the tire surface.
All wheels must have a valve cap to protect
the valve against dirt and moisture. Do not
mount anything onto the valve other than the
standard valve cap or other valve caps
approved by Mercedes-Benz for your vehicle. Do not use any other valve caps or systems,
e.g. tire pressure monitoring systems.
Regularly check the pressure of all the tires
particularly prior
to

long trips. Adjust the tire
pressure as necessary ( Y page 301).
The service life of tires depends, among other
things, on the following factors:
R Driving style
R Tire pressure
R Distance covered Tire tread
G
WARNING
Insufficient tire tread will reduce tire traction.
The tire is no longer able to dissipate water.
This means that

on wet road surfaces, the risk
of hydroplaning increases, in particular where
speed is not adapted to suit the driving
conditions. There is a risk of accident.
If the tire pressure is too high or too low, tires
may exhibit different levels of wear at
different locations on the tire tread. Thus, you
should regularly check the tread depth and
the condition of the tread across the entire
width of all tires.
Minimum tire tread depth for:
R Summer tires: â in (3 mm)
R M+S tires: ã in (4 mm)
For safety reasons, replace the tires before
the legally prescribed limit for the minimum
tire tread depth is reached. Operation
299
Wheels and tires Z
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