MERCEDES-BENZ C-CLASS CABRIOLET 2018 Owner's Manual

XTurn the SmartKey to position2in the igni-
tion lock.
XShift the automatic transmission to position
i.
As soon as the vehicle has been loaded:
XPrevent the vehicle from rolling away by
applying the electric parking brake.
XShift the automatic transmission to position
j.
XTurn the SmartKey to position uin the igni-
tion lock and remove it.
XSecure the vehicle.
Notes on 4MATIC vehicles
!
Vehicles with 4MATIC must not be towed
with either the front or the rear axle raised, as
doing so will damage the transmission.
Vehicles with 4MATIC may either be towed away
with both axles on the ground or be loaded up
and transported.
If the vehicle's transmission, front, or rear axle is
damaged, have the vehicle transported on a
truck or trailer.
In the event of damage to the electrical sys-
tem: if the battery is defective, the automatic
transmission will be locked in position P. To shift
the automatic transmission to position N, you
must provide power to the vehicle's electrical
system in the same way as when jump-starting
(
Ypage 304).
Have the vehicle transported on a transporter or
trailer.
Tow-starting (emergency engine
starting)
!
Vehicles with automatic transmission must
not be tow-started. You could otherwise dam-
age the automatic transmission.
iYou can find information on "Jump-starting"
under (Ypage 304).
Fuses
Important safety notes
GWARNING
If you manipulate or bridge a faulty fuse or if
you replace it with a fuse with a higher amper- age, the electric cables could be overloaded.
This could result in a fire. There is a risk of an
accident and injury.
Always replace faulty fuses with the specified
new fuses having the correct amperage.
Blown fuses must be replaced with fuses of the
same rating, which you can recognize by the
color and value. The fuse ratings are listed in the
fuse allocation chart.
The fuse allocation chart is on the fuse box in the
trunk (
Ypage 311).
If a newly inserted fuse also blows, have the
cause traced and rectified at a qualified special-
ist workshop, e.g. an authorized Mercedes-Benz Center.
!Only use fuses that have been approved for
Mercedes-Benz vehicles and which have the
correct fuse rating for the system concerned.
Otherwise, components or systems could be
damaged.
!Make sure that no moisture can enter the
fuse box when the cover is open.
!When closing the cover, make sure that it is
lying correctly on the fuse box. Moisture seep-
ing in or dirt could otherwise impair the oper-
ation of the fuses.
The fuses in your vehicle serve to close down
faulty circuits. If a fuse blows, all the compo-
nents on the circuit and their functions stop
operating.
Before changing a fuse
Observe the important safety notes
(Ypage 309)
XSwitch off the engine.
XSwitch off all electrical consumers.
Fuses309
Breakdown assistance
Z

XMake sure that the ignition is switched off
(Ypage 124).
or
XWhen using the SmartKey, turn the SmartKey to position uin the ignition lock and remove
it (
Ypage 123).
XSecure the vehicle against rolling away
(Ypage 143).
All indicator lamps in the instrument cluster
must be off.
The fuses are located in various fuse boxes:
RFuse box on the driver's side of the dashboard
RFuse box in the front-passenger footwell
RFuse box in the engine compartment on the
driver's side
RFuse box under the trunk floor on the right-
hand side of the vehicle, when viewed in the
direction of travel
Dashboard fuse box
The fuse box is under a cover on the side of the dashboard. You can obtain further information
from an authorized Mercedes-Benz Center.
Fuse box in the front-passenger foot-
well
XOpen the front-passenger door.
XTo open: fold cover :out towards the rear
and remove it.
XTo close: clip in cover :at the rear.
XFold cover :forwards until it engages.
Fuse box in the engine compartment
GWARNING
When the hood is open and the windshield
wipers are set in motion, you can be injured by
the wiper linkage. There is a risk of injury.
Always switch off the windshield wipers and
the ignition before opening the hood.
XOpen the hood (Ypage 281).
XTo open: turn fastener ;on cover :coun-
ter-clockwise as far as it will go.
XRemove fuse box cover :up.
XUse a dry cloth to remove any moisture from
the fuse box.
XLoosen screws =, fold up fuse box lid ?and
remove it.
XTo close: check whether the seal is posi-
tioned correctly in lid ?.
XInsert lid?into the bracket at the rear of the
fuse box.
XFold down lid ?of the fuse box and tighten
screws =.
XInsert cover :and turn fastener ;clock-
wise as far as it will go.
XClose the hood.
310Fuses
Breakdown assistance

Fuse box in the trunk
Opening
XOpen thetrunk lid.
XLif tth etrunk floor up (Ypage 267).
XLiftup cover :in th etrunk recess panel in
th edirection of th earrow.
Closin g
XFold cover :bac kin th eopposit edirection
to th earrow.
Mak esure that cover :is in th erecess provi-
ded for it in th epanel trim.
iThe fus eallocation chart is locate din a
recess at th eside of th efus ebox .You can fin d
th ecorresponding fus erating and fus etyp e
on th efus eallocation chart .
Fuses311
Breakdown assistance
Z

Important safety notes
GWARNING
If wheels and tires of th ewrong siz eare used,
th ewhee lbrakes or suspension component s
may be damaged. Ther eis aris kof an acci-
dent.
Always replace wheels and tires wit hthose
that fulfill th especification sof th eoriginal
part .
When replacing wheels, mak esur eto use th e
correct:
Rdesignation
Rmodel
When replacing tires ,mak esur eto use th e
correct:
Rdesignation
Rmanufacturer
Rmodel
GWARNIN G
A flat tire severely impairs th edriving ,steer -
ing and braking characteristics of th evehicle.
Ther eis aris kof accident.
Tires without run-flat characteristics :
Rdo notdriv ewit h a flat tire.
Rimmediately replace th eflat tire wit hyour
emergenc yspar ewhee lor spar ewheel, or
consult aqualified specialist workshop.
Tires wit hrun-flat characteristics :
Rpay attention to theinformation and warn -
ing notice son MOExtended tires (tire swit h
run-flat characteristics).
Accessories that are no tapprove dfor your vehi-
cle by Mercedes-Ben zor are no tbein gused cor-
rectl ycan impair th eoperating safety.
Before purchasing and usin gnon-approve d
accessories, visit aqualified specialist work-
sho pand inquire about :
Rsuitability
Rlegal stipulation s
Rfactory recommendation sFurther information regarding wheels and tires
can be foun
dunder "Wheel/tire combinations"
(
Ypage 336).
You can ask for information regarding permitte d
wheel-tire combination sat an authorize d
Mercedes-Ben zCenter.
Information on tire pressur ecan be found:
Ron th eTir eand Loading Information placard
on th eB-pillar on th edriver' sside
(
Ypage 322)
Rin th etire pressur etable in th efuel filler flap
(Ypage 315)
Runder "Tir epressure" (Ypage 315)
Operation
Information on driving
Checkth etire pressur ewhen th evehicl eis
heavily laden and adjust prio rto atrip.
While driving ,pay attention to vibrations, noises
and unusual handlin gcharacteristics ,e.g. pull-
ing to on eside .This may indicat ethat th e
wheels or tires are damaged. If you suspec tthat
a tire is defective, reduce your spee dimmedi-
ately. Stop th evehicl eas soo nas possible to
chec kth ewheels and tires for damage. Hidden
tire damag ecould also be causing th eunusual
handlin gcharacteristics .If you fin dno sign sof
damage, hav eth etires and wheels checke dat a
qualified specialist workshop.
When parking your vehicle, mak esur ethat th e
tires do no tget deformed by th ecur bor other
obstacles. If they canno tbe avoided, driv eove r
obstacles suc has curbs slowly and at an obtuse
angle. Otherwise, you may damag eth ewheels
or tires .
Notes on high performance tires
GWARNIN G
Due to th especial tire tread in combination
wit hth eoptimized rubber compound ,there is
an increased ris kof hydroplaning and skid-
din gon damp or wet road surfaces. In addi-
tion ,tire traction is significantly reduce dat
low outside temperatures and low tire-oper -
ating temperatures .Ther eis aris kof an acci-
dent.
312Operation
Wheels and tires

Activate ESP®and adapt your driving style. At
outside temperatures below 50 ‡(10 †), use
M+S tires.
iDifferent driving styles may lead to high tire
wear and the tires may reach the minimum
tire tread depth after only a short time.
Regular checking of wheels and tires
GWARNING
Damaged tires can cause tire inflation pres-
sure 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.
Check wheels and tires for damage at least once
a month. Check wheels and tires after driving
off-road or on rough roads. Damaged wheels
can cause a loss of tire pressure.
Pay particular attention to damage such as:
RCuts in the tires
RPunctures in the tires
RTears in the tires
RBulges on tires
RDeformation or severe corrosion on wheels
Regularly check the tire tread depth and the
condition of the tread across the whole width of
the tire (
Ypage 313). 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 par-
ticularly prior to long trips. Adjust the tire pres-
sure as necessary (
Ypage 315).
The service life of tires depends, among other
things, on the following factors:
RDriving style
RTire pressure
RDistance covered
Notes on tire tread
GWARNING
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 con-
ditions. There is a risk of accident.
If the tire pressure is too high or too low, tires
may exhibit different levels of wear at differ-
ent 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:
RSummer tires: âin (3 mm)
RM+S tires: ãin (4 mm)
For safety reasons, replace the tires before
the legally prescribed limit for the minimum
tire tread depth is reached.
Marking :shows where the bar indicator
(arrow) for tread wear is integrated into the tire
tread.
Treadwear indicators (TWI) are required by law. Six indicators are positioned on the tire tread.
They are visible once a tread depth of approx-
imately áin (1.6 mm) has been reached. If this
is the case, the tire is so worn that it must be
replaced.
Selecting, mounting and replacing
tires
ROnly mount tires and wheels of the same type
and make.
Operation313
Wheels and tires
Z

Exception: it is permissible to install a differ-
ent type or make in the event of a flat tire.
Observe the "MOExtended tires (tires with
run-flat characteristics" section (
Ypage 297).
ROnly mount tires of the correct size onto the
wheels.
RBreak in new tires at moderate speeds for the
first 60 miles (100 km). The new tires only
reach their full performance after this dis-
tance.
RDo not drive with tires which have too little
tread depth, as this significantly reduces the
traction on wet roads (hydroplaning).
RReplace the tires after six years at the latest,
regardless of wear.
MOExtended tires (tires with run-flat
properties)
With MOExtended tires (tires with run flat char-
acteristics), you can continue to drive your vehi-
cle even if there is a total loss of pressure in one
or more tires.
MOExtended tires may only be used in conjunc-
tion with an active tire pressure loss warning
system or with an active tire pressure monitor
and on wheels specifically tested by Mercedes-
Benz.
Notes on driving with MOExtended tires with a
flat tire (
Ypage 297).
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.
Winter operation
General notes
Have your vehicle winter-proofed at a qualified
specialist workshop at the onset of winter.
Observe the notes in the "Changing a wheel"
section (
Ypage 331).
Driving with summer tires
At temperatures below 45 ‡ (+7 †), summer
tires lose elasticity and therefore traction and braking power. Change the tires on your vehicle
to M+S tire
s. Usingsu mmer tires at very cold
temperatures could cause cracks to form,
thereby damaging the tires permanently.
Mercedes-Benz cannot accept responsibility for
this type of damage.
GWARNING
Damaged tires can cause tire inflation pres-
sure 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.
M+S tires
GWARNING
M+S tires with a tire tread depth of less than
ã in (4 mm) are not suitable for use in winter
and do not provide sufficient traction. There is
a risk of an accident.
M+S tires with a tread depth of less than ãin
(4 mm) must be replaced immediately.
At temperatures below 45 ‡(+7 †), use winter
tires or all-season tires. Both types of tire are
identified by the M+S marking.
Only winter tires bearing the isnowflake
symbol in addition to the M+S marking provide
the best possible grip in wintry road conditions.
Only these tires will allow driving safety systems
such as ABS and ESP
®to function optimally in
winter. These tires have been developed specif-
ically for driving in snow.
Use M+S tires of the same make and tread on all
wheels to maintain safe handling characteris-
tics.
Always observe the maximum permissible
speed specified for the M+S tires you have
mounted.
When you have mounted the M+S tires:
XCheck the tire pressures (Ypage 318).
XVehicles for Canada: restart the tire pres-
sure loss warning system (Ypage 319).
XRestart the tire pressure monitor
(Ypage 321).
314Winter operation
Wheels and tires

Snow chains
GWARNING
If snow chains are installed to the front
wheels, they may drag against the vehicle
body or chassis components. This could
cause damage to the vehicle or the tires.
There is a risk of an accident.
To avoid hazardous situations:
Rnever install snow chains to the front
wheels
Ralways install snow chains in pairs to the
rear wheels.
For safety reasons, Mercedes-Benz recom-
mends that you only use snow chains that have
been specially approved for your vehicle by
Mercedes-Benz, or are of a corresponding
standard of quality. For more information,
please contact a qualified specialist workshop.
If you intend to mount snow chains, please bear
the following points in mind:
RSnow chains may not be mounted on all
wheel/tire combinations. Observe the infor-
mation regarding permitted wheel/tire com-
binations (
Ypage 336).
ROnly use snow chains when driving on roads
completely covered by snow. Remove the
snow chains as soon as possible when you
come to a road that is not snow-covered.
RLocal regulations may restrict the use of snow
chains. Observe the appropriate regulations if
you wish to mount snow chains.
RDo not exceed the maximum permissible
speed of 31 mph (50 km/h).
ROn vehicles with AIRMATIC, you must drive at
raised vehicle level if snow chains have been
installed (
Ypage 164).
RYou must never use Parking Pilot (Ypage 166)
when snow chains are installed.
You may wish to deactivate ESP
®when pulling
away with snow chains installed:
RAll vehicles (except Mercedes ‑AMG vehicles)
(Ypage 68)
RMercedes‑AMG vehicles (Ypage 69)
You can thereby allow the wheels to spin in a
controlled manner, achieving an increased driv- ing force (cutting action).
Tire pressure
Tire pressure specifications
Important safety notes
GWARNING
Underinflated or overinflated tires pose the
following risks:
Rthe tires may burst, especially as the load
and vehicle speed increase.
Rthe tires may wear excessively and/or
unevenly, which may greatly impair tire
traction.
Rthe driving characteristics, as well as steer-
ing and braking, may be greatly impaired.
There is a risk of an accident.
Follow recommended tire inflation pressures
and check the pressure of all the tires includ-
ing the spare wheel:
Rmonthly, at least
Rif the load changes
Rbefore beginning a long journey
Runder different operating conditions, e.g.
off-road driving
If necessary, correct the tire pressure.
The data on the Tire and Loading Information
placard and tire pressure table shown here are
examples. Tire pressure specifications are vehi-
cle-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.
Further information on tire pressures can be
obtained at a qualified specialist workshop.
Tire pressure315
Wheels and tires
Z

Tire and Loading Information placard
:Recommended tire pressures
The Tire and Loading Information placard is on
the B-pillar on the driver's side (
Ypage 322).
The Tire and Loading Information placard con-
tains 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. It shows the tire pressure for all tires
permitted at the factory for this vehicle; see
illustration (example).
The tire pressure table contains the recommen-
ded pressures for cold tires for various operat-
ing conditions, i.e. differing load and speed con-
ditions.
If a tire size precedes a tire pressure, the tire
pressure information following is only valid for
that tire size. If a speed range precedes the tire pressure, the following tire pressure data
applies to only this speed range.
The load conditions "partially laden" and "fully
laden" are defined in the table for different num- bers 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.
Rim diameter is part of the tire size and can be
found on the tire sidewall (
Ypage 326).
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:
Rif you want to drive with an increased load
and/or
Rif you want to drive at higher road speeds
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 excessive build up of heat and a sud-
den loss of pressure.
For more information, contact a qualified spe-
cialist workshop.
Important notes on tire pressure
GWARNING
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.
RCheck the tire for foreign objects.
RCheck whether the wheel is losing air or the valve is leaking.
If you are unable to rectify the damage, con-
tact a qualified specialist workshop.
316Tire pressure
Wheels and tires

GWARNING
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 pres- sure 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 elec-
tronic tire pressure monitor, the tire pressure
can be checked in 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 pres-
sures when the tires are cold.
The tires are cold:
Rif the vehicle has been parked with the tires
out of direct sunlight for at least three hours
and
Rif the vehicle has not been 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 account when 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:
Ron the Tire and Loading Information placard
on the B-pillar on the driver's side
Rin the tire pressure table on the fuel filler flap
(Ypage 142)
Underinflated or overinflated tires
Underinflated tires
GWARNING
Tires with pressure that is too low can over-
heat and burst as a consequence. In addition, they also suffer from excessive and/or irreg-
ular wear, which can severely impair the brak-
ing 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:
Roverheat, leading to tire defects
Radversely affect handling
Rwear excessively and/or unevenly
Rhave an adverse effect on fuel consumption
Overinflated tires
GWARNING
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:
Rincrease the braking distance
Radversely affect handling
Rwear excessively and/or unevenly
Rhave an adverse effect on ride comfort
Rbe more susceptible to damage
Tire pressure317
Wheels and tires
Z

Maximum tire pressures
:Example: maximum permissible tire pres-
sure
Never exceed the maximum permissible tire
inflation pressure. Always observe the recom-
mended tire pressure for your vehicle when
adjusting the tire pressure (
Ypage 315).
iThe actual values for tires are vehicle-spe-
cific and may deviate from the values in the
illustration.
Checking the tire pressures
Important safety notes
Observe the notes on tire pressure
(Ypage 315).
Information on air pressure for the tires on your
vehicle can be found:
Ron the vehicle's Tire and Loading Information
placard on the B-pillar
Rin the tire pressure table in the fuel filler flap
(Ypage 142)
Rin the "Tire pressure" section
Checking tire pressures 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 to the
recommended value on the Tire and Loading
Information placard or the tire pressure table (
Ypage 315).
XIf the tire pressure is too low, increase the tire
pressure to the recommended value.
XIf the tire pressure is too high, release air. To
do so, press down the metal pin in the valve,
using the tip of a pen for example. Then check
the tire pressure again using the tire pressure
checker.
XScrew the valve cap onto the valve.
XRepeat these steps for the other tires.
Tire pressure loss warning system
General notes
While the vehicle is in motion, the tire pressure
loss warning system monitors the set tire pres-
sure 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.
You can recognize the tire pressure loss warning
by the Run Flat Indicator Active
Press'OK' to Restartmessage which appears in
the Servicemenu of the multifunction display.
Information on the message display can be
found in the "Restarting the tire pressure loss
warning system" section (
Ypage 319).
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
(
Ypage 315).
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 pres-
sure 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
movements.
The function of the tire pressure loss warning
system is limited or delayed if:
Rsnow chains are mounted on your vehicle's
tires.
Rroad conditions are wintry.
318Tire pressure
Wheels and tires