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 366).
X Make sure that the SmartKey is in
position 2 (Y
page 153) in the ignition lock.
X Press = or ; on the steering wheel
to select the Serv.Serv. menu.
X Press the 9 or : button to select
Tire Pressure.
X Press the a button.
The message appears in the multifunction
display.
If you wish to confirm the restart:
X Press the a button.
The Tire Pressure Now OK? message
appears in the multifunction display.
X Press the 9 or : button to select
Yes.
X Press the a button.
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 % button.
or
X When the Tire Pressure Now OK?
message appears, press the 9
or : button to select Cancel.
X Press the a button.
The tire pressure values stored at the last
restart will continue to be monitored. Tire pressure monitor
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 370
Tire pressure
Wheels and tires
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.
i USA only:
This device complies with part 15 of the
FCC Rules. Operation is subject to the
following two conditions:
1. This device may not cause interference,
and
2. this device must accept any interference
received, including interference that may
cause undesired operation of the device.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.
i Canada only:
This device complies with RSS-210 of
Industry Canada. Operation is subject to
the following two conditions:
1. This device may not cause interference,
and
2. this device must accept any interference
received, including interference that may
cause undesired operation.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.
Checking tire pressure electronically X
Make sure that the SmartKey is in
position 2 (Y
page 153) in the ignition lock.
X Press the = or ; button on the
steering wheel to select the Serv. menu. X
Press the 9 or : button to select
Tire Pressure.
X Press button a.
The
current tire pressure for each wheel will
be displayed in the multifunction display.
If the vehicle was parked for longer than
20 minutes the Tire pressures will be
displayed after driving a few
minutes message is shown.
After a teach-in period, the tire pressure
monitor
automatically recognizes new wheels
or new sensors. If a clear allocation of the tire
pressure values to the individual wheels is not
possible, the 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
significant
pressure loss on one or more tires,
a warning message is shown in the
multifunction display. A warning tone also
sounds and the tire pressure warning lamp
lights up in the instrument cluster.
Each tire that is affected by a significant loss
of pressure is highlighted in the pressure
display.
X If the Correct Tire Pressure message
appears
in the multifunction display, check
the tire pressure on all four wheels and
correct it if necessary.
i If the wheel positions on the vehicle are
interchanged, the tire pressures may be
displayed for the wrong positions for a
short time. This is rectified after a few 372
Tire pressure
Wheels and tires
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
A Load bearing index
B Speed 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
description (as shown above): these are
passenger vehicle tires according to
European manufacturing 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.
manufacturing standards.
If "T" precedes the size description: these are
compact emergency spare wheels at high tire
pressure, to be used only temporarily 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 ratio is calculated by dividing the tire width by
the tire height.
Tire
code: tire code = specifies the tire type.
"R" represents radial tires; "D" represents
diagonal tires; "B" represents diagonal radial
tires.
Optionally, tires with a maximum speed of
over 149 mph (240 km/h) may have a “ZR”
in the size description, depending on the
manufacturer (e.g. 245/40 ZR 18).
Rim diameter: rim diameter ? is the
diameter of the bead seat, not the diameter
of the rim flange. The rim diameter is
specified in inches (in).
Load-bearing index: load-bearing index A
is a numerical code that specifies the
maximum load-bearing capacity of a tire.
Do not overload the tires by exceeding the
specified load limit. The maximum
permissible load can be found on the
vehicle's Tire and Loading Information
placard on the B-pillar on the driver's side
(Y page 373).
Example:
The load bearing index 91 is equivalent to a
maximum load of 1356 lb (615 kg) that the
tire can carry. For further information on the
maximum tire load in kilograms and lbs, see
(Y page 381).
For further information on the load bearing
index, see "Load index" ( Y page 381).
Speed rating: speed rating B specifies the
approved maximum speed of the tire.
i Tire data is vehicle-specific and may
deviate from the data in the example.
Regardless of the speed rating, always
observe the speed limits. Drive carefully and
adapt your driving style to the traffic
conditions.
Summer tires Index Speed rating
Q up to 100 mph (160 km/h)
R up to 106 mph (170 km/h)All about wheels and tires
379
Wheels and tires Z
Speed rating
The speed rating is part of the tire
identification.
It specifies the speed range for
which the tire is approved.
GVW (Gross Vehicle Weight)
The gross vehicle weight includes the weight
of the vehicle including fuel, tools, the spare
wheel, accessories installed, occupants,
luggage and the drawbar noseweight, if
applicable. The gross vehicle weight must not
exceed the gross vehicle weight rating GVWR
as specified on the vehicle identification plate
on the B-pillar on the driver's side.
GVWR (Gross Vehicle Weight Rating)
The GVWR is the maximum permissible gross
weight of a fully loaded vehicle (the weight of
the vehicle including all accessories,
occupants, fuel, luggage and the drawbar
noseweight, if applicable). The gross vehicle
weight rating is specified on the vehicle
identification plate on the B-pillar on the
driver's side.
Maximum loaded vehicle weight
The maximum weight is the sum of:
R the curb weight of the vehicle
R the weight of the accessories
R the load limit
R the weight of the factory installed optional
equipment
Kilopascal (kPa)
Metric unit for tire pressure. 6.9 kPa
corresponds to 1 psi. Another unit for tire
pressure is bar. There are 100 kilopascals
(kPa) to 1 bar.
Load index
In addition to the load-bearing index, the load
index may also be imprinted on the sidewall
of the tire. This specifies the load-bearing
capacity more precisely. Curb weight
The weight of a vehicle with standard
equipment including the maximum capacity
of
fuel, oil and coolant. It also includes the air-
conditioning system and optional equipment
if these are installed in the vehicle, but does
not include passengers or luggage.
Maximum load rating
The maximum tire load is the maximum
permissible weight in kilograms or lbs for
which a tire is approved.
Maximum permissible tire pressure
Maximum permissible tire pressure for one
tire.
Maximum load on one tire
Maximum load on one tire. This is calculated
by dividing the maximum axle load of one axle
by two.
PSI (pounds per square inch)
A standard unit of measure for tire pressure.
Aspect ratio
Relationship between tire height and tire
width in percent.
Tire pressure
This is pressure inside the tire applying an
outward force to each square inch of the tire's
surface. The tire pressure is specified in
pounds per square inch (psi), in kilopascal
(kPa) or in bar. The tire pressure should only
be corrected when the tires are cold.
Cold tire pressure
The tires are cold:
R if the vehicle has been parked without
direct sunlight on the tires for at least three
hours and
R if the vehicle has been driven for less than
1 mile (1.6 km). All about wheels and tires
383
Wheels and tires Z
!
To prevent damage to the paintwork, hold
the wheel securely against the wheel hub
while screwing in the first wheel bolt. Positioning a wheel (example: vehicle with
emergency spare wheel)
X
Clean the wheel and wheel hub contact
surfaces.
X Slide the wheel to be mounted onto the
alignment bolt and push it on.
X Tighten the wheel bolts until they are
finger-tight.
X Unscrew the alignment bolt.
X Tighten the last wheel bolt until it is finger-
tight.
X Vehicles with a collapsible spare
wheel: inflate the collapsible spare wheel
(Y page 400).
Only then lower the vehicle.
Lowering the vehicle G
WARNING
The wheels could work loose if the wheel nuts
and bolts are not tightened to the specified
tightening torque. There is a risk of accident.
Have the tightening torque immediately
checked at a qualified specialist workshop
after a wheel is changed.
! Vehicles with a collapsible spare
wheel: before lowering the vehicle, inflate
the collapsible spare wheel with the tire
inflation compressor. The wheel rim could
otherwise be damaged. Tightening wheel bolts (example: vehicle with
emergency spare wheel)
X
Turn the crank of the jack counter-
clockwise until the vehicle is once again
standing firmly on the ground.
X Place the jack to one side.
X Tighten the wheel bolts evenly in a
crosswise pattern in the sequence
indicated ( :
to A). The tightening torque
must be 96 lb-ft (130 Nm).
X Turn the jack back to its initial position.
X Stow the jack and the rest of the vehicle
tools in the trunk again.
X AMG vehicles and vehicles with AMG
equipment:
insert the cover into the outer
sill.
X Check the tire pressure of the newly
mounted wheel and adjust it if necessary.
Observe the recommended tire pressure
(Y page 366).
i Vehicles with tire pressure monitor: all
wheels mounted must be equipped with
functioning sensors. Wheel and tire combinations
General notes
! For safety reasons, Mercedes-Benz
recommends that you only use tires and
wheels which have been approved by
Mercedes-Benz specifically for your
vehicle. Wheel and tire combinations
389
Wheels and tires Z
R18
Tires Alloy wheels
245/40 R18 97 H XL M+S
i RA: 8.5 J x 18 H2
Wheel offset: 1.89 in
(48 mm)Emergency spare wheel
Important safety notes
G
WARNING
The wheel or tire size as well as the tire type
of
the spare wheel or emergency spare wheel
and the wheel to be replaced may differ.
Mounting an emergency spare wheel may
severely impair the driving characteristics.
There is a risk of an accident.
To avoid hazardous situations:
R adapt your driving style accordingly and
drive carefully.
R never install more than one spare wheel or
emergency spare wheel that differs in size.
R only use a spare wheel or emergency spare
wheel of a different size briefly.
R do not switch ESP ®
off.
R have a spare wheel or emergency spare
wheel of a different size replaced at the
nearest qualified specialist workshop.
Observe that the wheel and tire dimensions
as well as the tire type must be correct.
When using an emergency spare wheel or
spare wheel of a different size, you must not
exceed the maximum speed of 50 mph
(80 km/h).
Snow chains must not be mounted on
emergency spare wheels. General notes
You should regularly check the pressure of
the
emergency spare wheel, particularly prior
to long trips, and correct the pressure as
necessary (Y page 366). The applicable value is found on the wheel or under "Technical
data" (
Y page 402).
An emergency spare wheel may also be
mounted against the direction of rotation.
Observe
the time restriction on use as well as
the speed limitation specified on the
emergency spare wheel.
Replace the tires after six years at the latest,
regardless of wear. This also applies to the
emergency spare wheel.
i When you are driving with the collapsible
spare wheel mounted, the tire pressure
loss warning system or the tire pressure
monitor cannot function reliably. Only
restart the tire pressure loss warning
system/the tire pressure monitor when the
damaged wheel has been replaced with a
new wheel.
Vehicles with tire pressure monitor:
after mounting an emergency spare wheel,
the system may still display the tire
pressure of the removed wheel for a few
minutes. The value displayed for the
mounted emergency spare wheel is not the
same as the current tire pressure of the
emergency spare wheel. 398
Emergency spare wheel
Wheels and tires
Removing the "Minispare"
emergency spare wheel/collapsible
spare wheel
Opening the stowage well Example: well insert
Sedan: the emergency spare wheel can be
found in the stowage well under the trunk
floor.
X
Lift the trunk floor upwards (Y page 301).
X Release tabs : on the right of well
insert ;.
X Reach into recess = of well insert ;,
swing the insert up and remove it.
Wagon: the emergency spare wheel is
located in the stowage well under the cargo
compartment floor.
X Remove the seat cushions of the folding
bench seat (Y page 108).
X Lift the cargo compartment floor up. Removing the emergency spare wheel
(Sedan) Example: Sedan
X
Remove vehicle tool kit tray :.
X Turn stowage tray ; counter-clockwise
and remove it.
X Remove "Minispare" emergency spare
wheel =.
Removing the emergency spare wheel
(Wagon) Example: emergency spare wheel
X
Remove vehicle tool kit tray : by
recess ;.
X Remove "Minispare" emergency spare
wheel =. Emergency spare wheel
399Wheels and tires Z
Removing the emergency spare wheel
(AMG vehicles)
X
Reach into cutout : in the tool holder and
lift it up.
X Remove collapsible spare wheel ;.
For further information on changing and
mounting a wheel, see
(Y page 385). Stowing a used collapsible spare
wheel
! Only place the collapsible spare wheel in
the vehicle when it is dry. Otherwise,
moisture may get into the vehicle.
Take the following steps to stow a used
collapsible spare wheel. It will not otherwise
install into the spare wheel well. Mercedes-
Benz recommends that you have this work
performed
at a qualified specialist workshop,
e.g. at an authorized Mercedes-Benz Center.
X Unscrew the valve cap from the valve.
X Use the back of the valve cap to unscrew
the valve insert from the valve and release
the air.
i Fully deflating the tires can take a few
minutes.
X Screw the valve insert back into the valve.
X Screw the valve cap back on. X
Remove the protective sheet from the
vehicle tool kit and pull it over the
collapsible spare wheel.
X Stow the collapsible spare wheel in the
emergency spare wheel well under the
trunk. Inflating the collapsible spare wheel
! Inflate the collapsible spare wheel using
the tire inflation compressor before
lowering the vehicle. The wheel rim could
otherwise be damaged.
! Do not operate the tire inflation
compressor for longer than eight minutes
at
a time without a break. It may otherwise
overheat.
The tire inflation compressor can be
operated again once it has cooled down. X
Mount the collapsible spare wheel as
described ( Y page 384).
The collapsible spare wheel must be
mounted before it is inflated.
X Pull connector ? and the air hose out of
the housing.
X Remove the cap from the valve on the
collapsible spare wheel.
X Screw union nut :
on the air hose onto the
valve.
X Make sure on/off switch A of the tire
inflation compressor is set to 0.400
Emergency spare wheel
Wheels and tires