2012 MERCEDES-BENZ C-Class SEDAN tire pressure

Display messagesPossible causes/consequences and M SolutionsCheck Tire
Pressure SoonGRisk of accident
The tire pressure loss warning system has detected a significant
loss in pressure.
A warning tone also sounds.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.XCheck the tires and, if necessary, change the wheel
( Y page 334).XCheck the tire pressures and, if necessary, set to the correct
tire pressure.XRestart the tire pressure loss warning system when the tire
pressure is correct ( Y page 317).Check Tire Pressure
Then Restart Run
Flat IndicatorThe tire pressure loss warning system generated a display
message and has not been restarted since.XSet the correct tire pressure in all four tires.XRestart the tire pressure loss warning system ( Y page 317).Run Flat Indicator
InoperativeThe tire pressure loss warning system is defective.XVisit a qualified specialist workshop.Tire pressures
will be displayed
after driving a
few minutesThe tire pressure monitor is measuring the tire pressure.XDrive on.
The tire pressures appear in the multifunction display after you
have been driving for a few minutes.Tire Press. Monitor
InoperativeThe tire pressure monitor is defective.XVisit a qualified specialist workshop.Tire Press. Monitor
Inoperative No
Wheel SensorsThe wheels mounted do not have a suitable tire pressure sensor.
The tire pressure monitor is deactivated.XMount wheels with suitable tire pressure sensors.
The tire pressure monitor is activated automatically after driving
for a few minutes.234Display messagesOn-board computer and displays

Display messagesPossible causes/consequences and M SolutionsCheck
TiresGRisk of accident
The tire pressure in one or more tires has dropped significantly.
The wheel position is displayed in the multifunction display.
A warning tone also sounds.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.XCorrect the tire pressure ( Y page 319).XIf necessary, change a wheel ( Y page 334).Caution:
Tire MalfunctionGRisk of accident
The tire pressure in one or more tires has dropped suddenly. The
wheel position is displayed in the multifunction display.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.XIf necessary, change a wheel ( Y page 334).Correct
Tire PressureThe tire pressure is too low in at least one of the tires or the tire
pressure difference between the wheels is too great.XCheck the tire pressures at the next opportunity. If necessary,
correct the tire pressure ( Y page 319).XRestart the tire pressure monitor ( Y page 321).Tire Press.
Sensor(s) MissingThere is no signal from the tire pressure sensor of one or several
wheels. The pressure of the affected tire is not displayed in the
multifunction display.XHave the defective tire pressure sensor replaced at a qualified
specialist workshop.Tire Press. Monitor
Currently Unavail.Due to a source of radio interference, no signals can be received
from the wheel sensors. The tire pressure monitor is temporarily
malfunctioning.XDrive on.
The tire pressure monitor restarts automatically as soon as the
problem has been solved.h
Tire Press.
Warning Caution
Tire MalfunctionGRisk of accident
The tire pressure in one or more tires has dropped suddenly.
A warning tone also sounds.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.XIf necessary, change a wheel ( Y page 334).Display messages235On-board computer and displaysZ

Display messagesPossible causes/consequences and M Solutionsh
Check Tire PressureGRisk of accident
The tire pressure in one or more tires has dropped significantly.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.XIf necessary, change a wheel ( Y page 334).XCheck the tire pressure. If necessary, correct the tire pressure
( Y page 319).h
Correct Tire
PressureThe tire pressure is too low in at least one of the tires or the tire
pressure difference between the wheels is too great.XCheck the tire pressures at the next opportunity. If necessary,
correct the tire pressure ( Y page 319).
Vehicle
Display messagesPossible causes/consequences and M SolutionsShift to 'P' or 'N'
to Start EngineYou have attempted to start the engine with the transmission in
position R or D.XShift the transmission to position P or N.P
Shift to 'P'You have attempted to stop the engine with the Start/Stop button
while the transmission was not in position P.XShift the transmission to position P.While the HOLD function or DISTRONIC PLUS is active, you have:
R opened the driver's door and released the seat belt or
R switched off the engine or
R opened the hood
A tone may also sound at regular intervals. The tone becomes
louder if you attempt to lock the vehicle.
You cannot start the engine.XShift the transmission to position P.
You can restart the engine.NThe trunk lid is open.XClose the trunk lid.236Display messagesOn-board computer and displays

TiresProblemPossible causes/consequences and M Solutionsh
USA only:
The yellow tire pressure
monitor warning lamp
(pressure loss/
malfunction) is lit.
Canada only:
The yellow tire pressure
monitor warning lamp
(pressure loss) is lit.GRisk of accident
The tire pressure monitor has detected a loss of pressure in at
least one of the tires.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.XObserve the additional display messages in the multifunction
display.XCheck the tire pressure. If necessary, correct the tire pressure
( Y page 319).XIf necessary, change a wheel ( Y page 334).h
USA only:
The yellow tire pressure
monitor warning lamp
(pressure loss/
malfunction) flashes for
60 seconds and then
remains lit.The tire pressure monitor is faulty.XObserve the additional display messages in the multifunction
display.XVisit a qualified specialist workshop.GWARNING
Each tire, including the spare (if provided), should be checked at least every two 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, if available, 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 when 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 telltale will flash for approximately
1 minute and then remain continuously illuminated. This sequence will be repeated every time
250Warning and indicator lamps in the instrument clusterOn-board computer and displays

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.Warning and indicator lamps in the instrument cluster251On-board computer and displaysZ

XPlace the emergency spare wheel on the
wheel hub and push it on.XTighten the wheel bolts until they are
finger-tight.
Lowering the vehicle
XTurn the crank of the jack counter-
clockwise until the vehicle is once again
standing firmly on the ground.XPlace the jack to one side.XTighten the wheel bolts evenly in a
crosswise pattern in the sequence
indicated ( : to A). The tightening torque
must be 96 lb-ft (130 Nm) .GWARNING
Have the tightening torque checked
immediately after a wheel is changed. The
wheels could come loose if they are not
tightened to a torque of 96 lb/ft (130 Nm).
XTurn the jack back to its initial position and
store it together with the rest of the tire-change tool kit in the trunk/cargo
compartment.XTransport the defective wheel in the trunk/
cargo compartment.
or
XDepending on the size of the wheel, you
may also be able to secure the defective
wheel in the spare wheel well. In this case,
you will have to remove the stowage well
casing from the spare wheel well and stow
it securely in the trunk/cargo
compartment.
i USA only: when you are driving with the
emergency spare wheel mounted, the tire
pressure monitoring system cannot
function reliably. Only restart the tire
pressure monitoring system when the
defective wheel has been replaced with a
new wheel.
All wheels mounted must be equipped with
functioning sensors. The defective wheel
should no longer be in the vehicle.
MOExtended tires (tires with run-flat
properties)
MOExtended tires (tires with run-flat
properties) allow you to continue driving your
vehicle even if one or more tires are entirely
deflated.
MOExtended tires may only be used in
conjunction with the activated tire pressure
loss warning system or with the activated tire
pressure monitoring system.
The maximum permissible distance which
can be driven in run-flat mode depends on the
load in the vehicle. You can drive 50 miles
(80 km) if the vehicle is partially laden and
18 miles (30 km) if it is fully laden.
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).
Flat tire297Breakdown assistanceZ

Useful information ............................310
Important safety notes ....................310
Operation ........................................... 310
Winter operation ............................... 312
Tire pressure ..................................... 313
Loading the vehicle ..........................322
Maximum load rating .......................325
Uniform Tire Quality Grading
Standards .......................................... 326
Tire labeling ....................................... 327
Definition of terms for tires and
loading ............................................... 331
Changing a wheel ............................. 334
Wheel and tire combinations ...........335309Wheels and tires

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 Please read the information on qualified
specialist workshops ( Y page 24).
Important safety notes
Consult an authorized Mercedes-Benz Center
if you require information on approved and
recommended tires and wheels for summer
and winter operation. Advice on purchasing
and caring for tires is also available there.
GWARNING
Replace rims or tires with the same
designation, manufacturer and type as shown
on the original part. For further information
contact an authorized Mercedes-Benz Center.
If incorrectly sized rims and tires are
mounted, the wheel brakes or suspension
components can be damaged. Also, the
operating clearance of the wheels and the
tires may no longer be correct.
GWARNING
Worn, old tires can cause accidents. If the tire
tread is worn to minimum tread depth, or if
the tires have sustained damage, replace
them.
When replacing rims, only use genuine
Mercedes-Benz wheel bolts specified for the
particular rim type. Failure to do so can result
in the bolts loosening and possibly an
accident.
Retreaded tires are not tested or
recommended by Mercedes-Benz, since
previous damage cannot always be
recognized on retreads. The operating safety
of the vehicle cannot be assured when such
tires are used.GWARNING
If you feel a sudden significant vibration or
ride disturbance, or you suspect that possible
damage to your vehicle has occurred, you
should turn on the hazard warning flashers,
carefully slow down, and drive with caution to
an area which is a safe distance from the road.
Inspect the tires and the vehicle underbody
for possible damage. If the vehicle appears
unsafe, have the vehicle towed to the nearest
authorized Mercedes-Benz Center or tire
dealer for repairs.
GWARNING
Do not drive with a flat tire. A flat tire affects
the ability to steer or brake the vehicle. You
might lose control of the vehicle. Continued
driving with a flat tire or driving at high speed
with a flat tire will cause excessive heat build-
up and possibly a fire.
i Further information about Tires and
wheels can be obtained from any
authorized Mercedes-Benz Center.
Operation
Notes on driving
R If the vehicle is heavily laden, check the tire
pressures and correct them if necessary.
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, can get
damaged.
310OperationWheels and tires