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

In order for the battery to achieve the maximum
possible service life, it must always be suffi-
ciently charged.
Like other batteries, the vehicle battery may
discharge over time if you do not use the vehicle.
In this case, have the battery disconnected at a
qualified specialist workshop. You can also
charge the battery with a charger recommended
by Mercedes-Benz. Contact a qualified special-
ist workshop for further information.
Have the battery condition of charge checked
more frequently if you use the vehicle mainly for
short trips or if you leave it standing idle for a
lengthy period. Consult a qualified specialist
workshop if you wish to leave your vehicle
parked for a long period of time.
Remove the SmartKey if you park the vehicle
and do not require any electrical consumers.
The vehicle will then use very little energy, thus
conserving battery power.
Charging the 12 V battery
Vehicles with a lithium-ion battery:
!Only use battery chargers with a maximum
charging voltage of 14.4 V.
All vehicles except vehicles with a lithium-
ion battery:
!Only use battery chargers with a maximum
charging voltage of 14.8 V.
GWARNING
During charging and jump-starting, explosive
gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, open flames, creating
sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting.
Do not lean over a battery.
GWARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do
not inhale any battery gases. Do not lean over
the battery. Keep children away from batter-
ies. Wash away battery acid immediately with
plenty of clean water and seek medical atten-
tion.
GWARNING
A discharged battery can freeze at tempera-
tures below freezing point. When jump-start-
ing the vehicle or charging the battery, gases can escape from the battery. There is a risk of
an explosion.
Allow the frozen battery to thaw out before
charging it or jump-starting.
All vehicles:
!Only charge the battery using the jump-
starting connection point.
The jump-starting connection point is in the
engine compartment (
Ypage 304).
XOpen the hood.
XConnect the battery charger to the positive
terminal and ground point in the same order
as when connecting the donor battery in the
jump-starting procedure (
Ypage 304).
Keep away from fire and open flames. Do not
lean over a battery. Never charge the battery if it
is still installed in the vehicle, unless you use a
battery charger which has been tested and
approved by Mercedes-Benz. A battery charger
unit specially adapted for Mercedes-Benz vehi-
cles and tested and approved by Mercedes-
Benz is available as an accessory. It permits the
charging of the battery in its installed position.
Contact an authorized Mercedes-Benz Center
for further information and availability. Read the
battery charger's operating instructions before
charging the battery.
All vehicles except vehicles with a lithium-
ion battery: if the warning and indicator lamps
on the instrument cluster do not light up at low
temperatures, it is very likely that the dis-
charged battery has frozen. In this case you may
neither jump-start the vehicle nor charge the
battery. The service life of a thawed-out battery
may be shorter. The starting characteristics can
be impaired, particularly at low temperatures.
Have the thawed-out battery checked at a quali-
fied specialist workshop.
Vehicles with a lithium-ion battery: at low
temperatures, do not charge a battery which has
been removed using a battery charger. Allow the
battery to warm up gently first, if necessary.
Otherwise, the service life can be shortened and
the starting characteristics impaired, especially
at low temperatures.
Battery (vehicle)303
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Z

Jump-starting
For the jump-starting procedure, use only the jump-starting connection point in the engine com-
partment, consisting of a positive terminal and a ground point.
All vehicles except vehicles with a lithium-ion battery:
GWARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do not inhale any battery gases. Do not lean over the
battery. Keep children away from batteries. Wash away battery acid immediately with plenty of
clean water and seek medical attention.
GWARNING
During charging and jump-starting, explosive gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, open flames, creating sparks and smoking. Ensure there is sufficient ven-
tilation while charging and jump-starting. Do not lean over a battery.
GWARNING
During the charging process, a battery produces hydrogen gas. If a short circuit occurs or sparks
are created, the hydrogen gas can ignite. There is a risk of an explosion.
RMake sure that the positive terminal of a connected battery does not come into contact with
vehicle parts.
RNever place metal objects or tools on a battery.
RIt is important that you observe the described order of the battery terminals when connecting
and disconnecting a battery.
RWhen jump-starting, make sure that the battery poles with identical polarity are connected.
RIt is particularly important to observe the described order when connecting and disconnecting
the jumper cables.
RNever connect or disconnect the battery terminals while the engine is running.
GWARNING
A discharged battery can freeze at temperatures below freezing point. When jump-starting the
vehicle or charging the battery, gases can escape from the battery. There is a risk of an explosion. Allow the frozen battery to thaw out before charging it or jump-starting.
If the warning and indicator lamps do not light up on the instrument cluster when temperatures are low, it is probably because the discharged battery has frozen. In this case, you may neither charge
the battery nor jump-start the vehicle. The service life of a thawed-out battery may be shorter. The
starting characteristics can be impaired, particularly at low temperatures. Have the thawed-out
battery checked at a qualified specialist workshop.
All vehicles:
!Avoid repeated and lengthy starting attempts. Otherwise, the catalytic converter could be
damaged by the non-combusted fuel.
304Jump-starting
Breakdown assistance

Do not start the vehicle using a rapid charging device. If your vehicle's battery is discharged, the
engine can be jump-started from another vehicle or from a second battery using jumper cables.
Observe the following points:
RThe battery is not accessible in all vehicles. If the other vehicle's battery is not accessible, jump-
start the vehicle using a second battery or a jump-starting device.
RYou may only jump-start the vehicle when the engine and exhaust system are cold.
RAll vehicles except vehicles with a lithium-ion battery: do not start the engine if the battery
is frozen. Let the battery thaw first.
RJump-starting may be performed only using batteries with a nominal voltage of 12 V.
ROnly use jumper cables which have a sufficient cross-section and insulated terminal clamps.
RIf the battery is fully discharged, leave the battery that is being used to jump-start connected for
a few minutes before attempting to start. This charges the battery slightly.
RMake sure that the two vehicles do not touch.
Make sure that:
RThe jumper cables are not damaged.
RBare parts of the terminal clamp do not come into contact with other metal parts while the jumper
cables are connected to the battery.
RThe jumper cables cannot come into contact with parts that can move when the engine is running,
such as the V-belt pulley or the fan.
XSecure the vehicle by applying the electric parking brake.
XShift the transmission to position j.
XMake sure that the ignition is switched off. All indicator lamps in the instrument cluster must be
off. When using the SmartKey, turn the SmartKey to position uin the ignition lock and remove it
(
Ypage 123).
XSwitch off all electrical consumers, e.g. rear window defroster, lighting, etc.
XOpen the hood.
Position number Cidentifies the charged battery of the other vehicle or an equivalent jump-starting
device.
XLift up panel B.
XSlide coverAof positive terminal :in the direction of the arrow.
Jump-starting305
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XConnect positive terminal:on your veh icleto positive terminal ;of donor battery Cusing the
jumper cable, Always begin with positive terminal :on your own vehicle first.
XStart the engine of the donor veh icleand run itat idling speed.
XConnect negative terminal =of donor battery Cto earth point ?of your vehicle using the
jumper cable. beginning with donor battery Cfirst.
XStart the engine.
XBefore disconnecting the jumper cables, let the engine run for several minutes.
XFirst, remove the jumper cables from ground point? and negative terminal =, then from pos-
itive clamp :and positive terminal ;. Begineach time at the contacts on your own vehicle first.
XClose cover Aof positive terminal :after removing jumper cables.
XFold panel Bshut.
XHave the battery checked at a qualified specialist workshop.
Jump-starting isnot cons idered to bea normal operating condition.
iJumper cables and further information regarding jump-starting can be obtained at any qualified
specialist workshop.
Towing and tow-starting
Important safety notes
GWARNING
Functions relevant to safety are restricted or
no longer availab leif:
Rthe engine isnot running.
Rthe brake system or the power steering is
malfunctioning.
Rthere isa malfunction inthe voltage supply
or the veh icle's electrical system.
If your veh icle is bein g towed, much more
force may benecessary to steer or brake.
There isa risk of an acc ident.
In such cases, use a tow bar. Before to wing,
make sure that the steering moves freely.
GWAR NING
You can no longer steer the veh icle ifthe
steering wheel lock has been engaged. There
is a risk of an acc ident.
Alwa ysswit ch off the ignition when to wingthe
veh icle wit h a tow cable or a tow bar.
GWARNING
When to wingor tow-starting another vehicle
and its weight isgreater than the permissible
gross weight of your vehicle, the:
Rthe to wingeye could detach itself
Rthe vehicle /trailer combination could roll-
over.
There is a risk of an accident.
When towing or tow-starting another vehicle,
its weight should not be greater than the per- missible gross weight of your vehicle.
Details on the permissible gross vehicle weight
of your vehicle can be found on the vehicle iden-
tification plate (
Ypage 339).
!When Active Brake Assist, Distance Pilot
DISTRONIC or the HOLD function is activated,
the vehicle brakes automatically in certain
situations.
To avoid damage to the vehicle, deactivate
these systems in the foll owing or similar sit-
uations:
Rwhen to wingthe vehicle
Rin the car wash
!Make sure that the electric parking brake is
released. Ifthe electric parking brake is faulty,
vis ita qualified specialist workshop.
!Secure the tow rope or tow bar to the to wing
eye only. Otherwise, the vehicle could
become damaged.
306Towing and tow-starting
Breakdown assistance

!Do not use the towing eye for recovery. This
could damage the vehicle. If in doubt, have
the vehicle recovered using a crane.
!When towing, pull away slowly and
smoothly. If the tractive power is too high, the
vehicles could be damaged.
!Shift the automatic transmission to position
i and do not open the driver's or front pas-
senger's door during towing. The automatic
transmission may otherwise shift to position
j, which could damage the transmission.
!Do not tow with sling-type equipment. This
could damage the vehicle.
!The vehicle can be towed a maximum of
30 miles (50km). The towing speed of 30 mph
(50 km/h) must not be exceeded.
If the vehicle has to be towed more than
30 miles (50km), the entire vehicle must be
raised and transported.
It is better to have the vehicle transported than
to have it towed away.
If the vehicle has suffered transmission damage,
have it transported on a transporter or trailer.
The automatic transmission must be in position
i when the vehicle is being towed. If the auto-
matic transmission cannot be shifted to position i, have the vehicle transported on a trans-
porter or trailer.
The battery must be connected and charged.
Otherwise, you:
Rcannot turn the SmartKey to position 2in
the ignition lock
Rcannot release the electric parking brake
Rcannot shift the automatic transmission to
position i
Disarm the automatic locking feature before the
vehicle is towed (
Ypage 82). You could other-
wise be locked out when pushing or towing the
vehicle.
Installing/removing the towing eye
Installing the towing eye
GWARNING
The exhaust tail pipe may be very hot. There is
a risk of burns when removing the rear cover.
Do not touch the exhaust pipe. Take particular care when removing the rear cover.
The brackets for the screw-in towing eye are
located in the bumpers. They are at the rear and
at the front, under covers :.
XRemove the towing eye from the retainer
(Ypage 296).
XPress the mark on cover:inward and
remove.
XScrew in the towing eye clockwise as far as it
will go and tighten it.
Removing the towing eye
XUnscrew and remove the towing eye.
XAttach cover :to the bumper and press until
it engages.
Towing the vehicle with the rear axle
raised
Only vehicles without 4MATIC can be towed
with the rear axle raised.
!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.
!Vehicles with automatic transmission must
not be towed with the rear axle raised. The
Towing and tow-starting307
Breakdown assistance
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vehicle/trailer combination may otherwise
swerve or even roll over.
Towing a vehicle with both axles on
the ground
The automatic transmission automatically shifts
to positionjwhen you open the driver's or
front-passenger door or when you remove the
SmartKey from the ignition lock. It is essential to
observe the following steps to ensure that the
automatic transmission remains in position i
during towing.
XMake sure that the vehicle is stationary.
XTurn the SmartKey to position 2in the igni-
tion lock.
XDepress and hold the brake pedal.
XShift the automatic transmission to position
N.
XLeave the SmartKey in position 2in the igni-
tion lock.
XRelease the brake pedal.
XRelease the electric parking brake.
XSwitch on the hazard warning lamps
(Ypage 109).
In order to signal a change of direction when
towing the vehicle with the hazard warning
lamps switched on, use the combination switch
as usual. In this case, only the indicator lamps
for the direction of travel flash. After resetting
the combination switch, the hazard warning
lamp starts flashing again.
Transporting the vehicle
4MATIC vehicles/vehicles with auto-
matic transmission
!When the vehicle is loaded for transport, the
front and rear axles must be stationary and on
the same transportation vehicle. Positioning
over the connection point of the transport
vehicle is not permitted. The drive train may
otherwise be damaged.
Vehicles with ADS PLUS (Adaptive
Damping System PLUS)
GWARNING
The weaker damping forces of the vehicle to
be transported can cause the vehicle/trailer
combination to swing.
As a result, when transporting vehicles with
Adaptive Damping System PLUS, the vehicle/
trailer combination may start to skid. Conse-
quently, you could lose control of the vehicle.
There is a risk of accident and injury.
When transporting, make sure that:
Rthe vehicle is has been loaded onto the
transporter correctly
Rthe vehicle is secured at all four wheels with
suitable tensioning straps
Ryou do not exceed the maximum permissi-
ble speed of 35 mph (60 km/h)
!After loading, the vehicle must be secured at
all four wheels. Otherwise, the vehicle could
be damaged.
A minimum distance of 8 in (20 cm) up and
4 in (10 cm) down must be maintained to the
transport platform.
XSecure all four wheels after loading the vehi-
cle.
All vehicles
!You may only secure the vehicle by the
wheels, not by parts of the vehicle such as
axle or steering components. Otherwise, the
vehicle could be damaged.
The towing eye can be used to pull the vehicle
onto a trailer or transporter for transporting pur-
poses.
308Towing and tow-starting
Breakdown assistance

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
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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