2012 MERCEDES-BENZ E-Class CABRIOLET change wheel

XSlide the emergency spare wheel onto the
alignment bolt and push it on.XTighten the wheel bolts until they are
finger-tight.XUnscrew the alignment bolt.XTighten the last wheel bolt until it is 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 stowage well under
the trunk floor.XVehicles with AMG equipment: if a front
wheel has been changed, insert the cover
into the outer sill.XTransport the defective wheel in the trunk.
i When you are driving with the collapsible
spare wheel mounted, the tire pressure
loss warning system or the tire pressure
monitoring system cannot function
reliably. Only restart the tire pressure loss
warning system/tire pressure monitoring
system when the defective wheel has been
replaced with a new wheel.
Vehicles with tire pressure monitoring
system: all mounted wheels must be
equipped with functioning sensors and 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 tire295Breakdown assistanceZ

GWARNING
The handling characteristics of your vehicle
deteriorate in run-flat mode, for example:
R when cornering
R when braking
R when accelerating rapidly
Adapt your driving style accordingly and avoid
sudden changes in direction and sudden
acceleration, as well as driving over obstacles
(i.e. curbs, potholes), and driving off-road.
This is particularly the case when the vehicle
is heavily laden.
The maximum permissible distance that can
be driven in run-flat mode depends to a large
extent on the loads placed on the vehicle. It
can be shorter due to high speeds, a heavy
load, sudden changes in direction, the road
surface condition, outside temperature, etc.,
or further if you drive carefully and
conservatively.
Do not continue to drive in run-flat 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 run-flat mode, you must have
the wheel(s) checked for damage at a
qualified specialist workshop which has the
necessary specialist knowledge and tools to
carry out the work required. The defective tire
must be replaced in every case.
Mercedes-Benz recommends that you use an
authorized Mercedes-Benz Center for this
purpose. In particular, work relevant to safety
or on safety-related systems must be carried
out at a qualified specialist workshop.
i When replacing one or all tires, make sure
that you only use tires marked
MOExtended and of the specified size for
the vehicle.
Battery
Important safety notes
In order for the battery to achieve the
maximum possible service life, it must always
be sufficiently charged.
! Have the battery checked regularly at a
qualified specialist workshop, such as an
authorized Mercedes-Benz Center.
Adhere to the service intervals indicated in
the service booklet or ask a qualified
specialist workshop, such as an authorized
Mercedes-Benz Center.
Have the battery charge checked more
frequently if you use the vehicle mainly for
short trips or if you leave it standing idle for
a lengthy period.
Only replace a battery with a battery that has
been recommended by Mercedes-Benz.
Consult an authorized Mercedes-Benz Center
if you wish to leave your vehicle parked for a
long period of time.
GWARNING
Comply with safety precautions and take
protective measures when handling batteries.
Risk of explosionFire, naked flames and
smoking are prohibited
when handling the battery.
Avoid creating sparks.Battery acid is caustic.
Avoid contact with the skin,
eyes or clothing.
Wear suitable protective
clothing, in particular
gloves, an apron and a face
mask.
Immediately rinse acid
splashes off with clean
water. Consult a doctor if
necessary.296BatteryBreakdown assistance

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.
Option 3) The tire pressure for the
emergency/collapsible spare wheel
(depending on vehicle equipment) can be
found:
R printed in yellow on the rim of the
emergency/collapsible spare wheel
R in the "Wheel and tire combinations"
section ( Y page 333) in this manual
R on the Tire and Loading Information placard
on the B-pillar on the driver's side.
If the tire pressure is not set correctly, this
can lead to an excessive build up of heat and
a sudden loss of pressure.
For further information, consult a qualified
specialist workshop, e.g. an authorized
Mercedes-Benz Center.
Important notes on tire pressureGWARNING
Should the tire pressure drop repeatedly:
R check the tire for foreign bodies.
R check whether the wheel is losing air or the
valve is leaking.
R make sure that only a valve cap approved
by Mercedes-Benz is used on the tire valve.
Tire pressures that are too low have a
negative effect on vehicle safety, which could
lead you to cause an accident.
To test tire pressure, use a suitable tire
pressure gauge. 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.
Therefore, you should only correct tire
pressures when the tires are cold.
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 not been driven more 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 account when
checking the pressure of warm tires and 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.
Tire pressure313Wheels and tiresZ

Checking the tire pressures
Important safety notesGWARNING
Follow recommended tire inflation pressures.
Do not underinflate tires. Underinflated tires
wear excessively and/or unevenly, adversely
affect handling and fuel economy, and are
more likely to fail from being overheated.
Do not overinflate tires. Overinflated tires can
adversely affect handling and ride comfort,
wear unevenly, increase stopping distance,
and result in sudden deflation (blowout)
because they are more likely to become
punctured or damaged by road debris,
potholes etc.
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard on the
driver's door B-pillar. Overloading the tires
can overheat them, possibly causing a
blowout. Overloading the tires can also result
in handling or steering problems, or brake
failure.
Check the tire pressure at least once a month.
Only check and correct tire pressures when
the tires are cold ( Y page 311).
Checking tire pressure manually
To determine and set the correct tire
pressure, proceed as follows:
XRemove the valve cap of the tire that is to
be checked.XPress the tire pressure gauge securely onto
the valve.XRead the tire pressure and compare it with
the recommended value on the Tire and
Loading Information placard on the
B-pillar on the driver's side of your vehicle.XIf necessary, increase the tire pressure to
the recommended value ( Y page 311).XIf the tire pressure is too high, release air
by pressing down the metal pin in the valve
using the tip of a pen, for example. Thencheck the tire pressure again using the tire
pressure gauge.XScrew the valve cap onto the valve.XRepeat these steps for the other tires.
Tire pressure loss warning system
(Canada only)
Important safety 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 appear in the multifunction
display.
GWARNING
If the Check Tire Pressure Soon message
appears in the multifunction display, one or
more tires are significantly underinflated.
Stop the vehicle as soon as possible and
inflate the tires to the pressure specified on
the vehicle's Tire and Loading Information
placard or (where available) in the tire
pressure table.
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.
Check all tires when cold, including the spare
tire, at least once a month. The tires should
be inflated to the recommended pressure.
This information can be found:
R on the Tire and Loading Information placard
on the B-pillar on the driver's side
or
R in the table for the tire pressure on the
inside of the fuel filler flap
Tire pressure315Wheels and tiresZ

GWARNING
The tire pressure loss warning system does
not provide a warning for wrongly selected tire
inflation pressures. Always adjust tire
inflation pressure according to the Tire and
Loading Information placard on the driver's
door B-pillar or on the tire inflation pressure
label located on the inside of the fuel filler flap.
The tire pressure loss warning system does
not replace regular checks of the tire inflation
pressures since a gradual pressure loss in
more than one tire cannot be detected by the
tire pressure loss warning system.
The tire pressure loss warning system is not
able to issue a warning due to a sudden
dramatic loss of tire inflation pressure (e.g.
tire blowout caused by a foreign object). In
this case bring the vehicle to a halt by carefully
applying the brakes and avoiding abrupt
steering maneuvers.
The function of the tire pressure loss warning
system is limited or delayed if:
R snow chains are mounted to 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
(cornering 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).
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 mount new wheels or tires
XBefore restarting, consult the Tire and
Loading Information placard on the
B-pillar on the driver's side or the tire
pressure table on the inside of the fuel filler
flap to ensure the tire pressure in all fourtires is set correctly for the current
operating conditions.XObserve the notes in the section on tire
pressures ( Y page 311).GWARNING
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.
A tire with insufficient pressure results in
vehicle instability when driving, thus
increasing the risk of an accident.
XMake sure that the SmartKey is in
position 2 ( Y page 145) in the ignition lock.XPress the = or ; button to select the
Serv. menu.XPress the 9 or : button to select
Tire Pressure .XPress the a button.
The Run Flat Indicator Active
Press 'OK' to Restart message
appears in the multifunction display.
If you wish to confirm the restart:
XPress the a button.
The Tire Pressure Now OK? message
appears in the multifunction display.XPress 9 or : to select Yes.XPress 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:
XPress the % button.
or
XIf the Tire Pressure Now OK? message
appears, press 9 or : to select
Cancel .316Tire pressureWheels and tires

flashing for 60 seconds and then remaining
lit.
When the malfunction has been rectified,
the tire pressure warning lamp goes out
after driving for a few minutes.
Information on tire pressures is displayed in
the multifunction display. After a few minutes
of driving, the current tire pressure of each
tire is shown in the multifunction display.
i 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.
i 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 This device complies with Part 15 of the
FCC Rules. Operation is subject to the
following two conditions:
1. This device may not cause harmful
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 electronicallyXMake sure that the SmartKey is in position
2 (Y page 145) in the ignition lock.XPress the = or ; button on the
steering wheel to select the Service
menu.XPress the 9 or : button to select
Tire Pressure .XPress the a button.
The current tire pressure for each wheel will
be displayed in the multifunction display.
If the vehicle has been parked for longer than
20 minutes, the Tire pressures will be
displayed after driving a few
minutes message appears in the display.
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 Tire Pressure Monitor
Active message is shown instead of the tire
pressure display. The tire pressures are
already being monitored.
i If a spare wheel/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 tire is
mounted is not the same as the spare
wheel/emergency spare wheel's current
tire pressure.
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 with a color.
If the Correct Tire Pressure message
appears in the multifunction display:
XCheck 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
318Tire pressureWheels and tires

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 monitorGWARNING
It is the driver's responsibility to set the tire
pressure to the recommended cold tire
pressure. Underinflated tires affect the ability
to steer or brake the vehicle. You might lose
control over the vehicle.
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
reference values for monitoring.
The tire pressure monitor must be restarted
when you set the tire pressure to a new value
(as a result of changed drive or load
characteristics, for example). The tire
pressure monitor then monitors the new tire
pressure values.
Restart the tire pressure monitor after you
have set the tire pressure to the value
recommended for the desired driving
situation ( Y page 311). Only correct tire
pressures on cold tires. Comply with the
recommended tire pressures on the Tire and
Loading Information placard on the B-pillar on
the driver's side. Additional tire pressure
values for driving at high speeds or with heavy
loads can be found in the tire pressure table
on the inside of the fuel filler flap.
XMake sure that the tire pressure is correct
on all four wheels.XMake sure that the SmartKey is in position
2 in the ignition lock.XPress the = or ; button on the
steering wheel to select the Serv. menu.XPress the 9 or : button to select
Tire Pressure .XPress the a button.
The multifunction display shows the
current tire pressure of the individual tiresor the Tire pressures will be
displayed after driving a few
minutes message.XPress the : button.
The Use Current Pressures as New
Reference Values message appears in
the multifunction display.
If you wish to confirm the restart:
XPress the a button.
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:
XPress the % button.
The tire pressure values stored at the last
restart will continue to be monitored.
Loading the vehicle
Instruction labels for tires and loads
GWARNING
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard on the
driver's door B-pillar. Overloading the tires
can overheat them, possibly causing a
blowout. Overloading the tires can also result
in handling or steering problems, or brake
failure.
Two instruction labels on your vehicle show
the maximum possible load.
(1)The Tire and Loading Information placard
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
permissible vehicle load. It also contains
details of the tire sizes andLoading the vehicle319Wheels and tiresZ

Traction
Traction is the result of friction between the
tires and the road surface.
Treadwear indicators
Narrow bars (tread wear bars) that are
distributed over the tire tread. If the tire tread
is level with the bars, the wear limit of 1
/ 16 in
(1.6 mm) has been reached.
Occupant distribution
The distribution of occupants in a vehicle at
their designated seating positions.
Total load limit
Rated cargo and luggage load plus
68 kilograms (150 lbs) times the vehicle's
designated seating capacity.
Changing a wheel
Flat tire
The "Breakdown assistance" section
( Y page 291) contains information and notes
on how to deal with a flat tire. It also provides
instructions on changing a wheel or mounting
the spare wheel/emergency spare wheel.
Interchanging the wheels
GWARNING
Rotate front and rear wheels only if the tires
are of the same dimension.
If your vehicle is equipped with mixed-size
tires (different tire dimensions front vs. rear),
tire rotation is not possible.
GWARNING
Have the tightening torque checked after
changing a wheel. Wheels could become
loose if not tightened with a torque of
96 lb-ft (130 Nm).
Only use genuine Mercedes-Benz wheel bolts
specified for your vehicle's rims.
The wear patterns on the front and rear tires
differ, depending on the operating conditions.
Rotate the wheels before a clear wear pattern
has formed on the tires. Front tires typically
wear more on the shoulders and the rear tires
in the center.
If your vehicle's tire configuration allows, you
can rotate the wheels according to the
intervals in the tire manufacturer's warranty
book in your vehicle documents. If this is not
available, the tires should then be replaced
every 3000 to 6000 miles
( 5000 to 10,000 km), or earlier if the tire wear
requires this. Do not change the direction of
wheel rotation.
Clean the contact surfaces of the wheel and
the brake disc thoroughly every time a wheel
is interchanged. Check the tire pressures.
Information on changing a wheel and
mounting the spare wheel ( Y page 291).
! On vehicles equipped with a tire pressure
monitor, electronic components are
located in the wheel.
Tire-mounting tools should not be used
near the valve. This could damage the
electronic components.
Always have the tires changed at a qualified
specialist workshop, e.g. an authorized
Mercedes-Benz Center.
Direction of rotation
Tires with a specified direction of rotation
have additional benefits, e.g. if there is a risk
of hydroplaning. You will only gain these
benefits if the correct direction of rotation is
maintained.
An arrow on the sidewall of the tire indicates
its correct direction of rotation.
332Changing a wheelWheels and tires