battery MERCEDES-BENZ C-CLASS CABRIOLET 2018 Owner's Guide

SmartKey
Display messagesPossible causes/consequences andMSolutions
Â
KeyDoesNotBelongto Vehicle
You have put the wrong SmartKey in the ignition lock.
XUse the correct SmartKey.
Â
Take Your Key fromIgnition
The SmartKey is in the ignition lock.
A warning tone sounds
XRemove the SmartKey.
Â
Obtain a New Key
The SmartKey needs to be replaced.
XVisit a qualified specialist workshop.
Â
Replace Key Battery
The SmartKey battery is discharged.
XChange the batteries (Ypage 79).
Â
Don't Forget YourKey
The SmartKey is not in the ignition lock. You have opened the driver's
door with the engine switched off. A warning tone sounds
This display message is displayed for a maximum of 60 seconds and is
simply a reminder.
XTake the SmartKey with you when you leave the vehicle.
Â
Key Not Detected(white display message)
The SmartKey is currently undetected.
XChange the location of the SmartKey in the vehicle.
If the SmartKey still cannot be detected:
XInsert the SmartKey into the ignition lock and turn it to the desired position.
Â
Key Not Detected(red display message)
The SmartKey is not in the vehicle.
A warning tone also sounds.
If the engine is switched off, you can no longer lock the vehicle cen-
trally or start the engine.
XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 143).
XLocate the SmartKey.
XPress aon the steering wheel to confirm the display message.
240Display messages
On-board computer and displays

Cigarette lighter
GWARNING
You can burn yourself if you touch the hot
heating element or the socket of the cigarette lighter.
In addition, flammable materials can ignite if:
Rthe hot cigarette lighter falls
Ra child holds the hot cigarette lighter to
objects, for example
There is a risk of fire and injury.
Always hold the cigarette lighter by the knob.
Always make sure that the cigarette lighter is
out of reach of children. Never leave children
unsupervised in the vehicle.
Your attention must always be focused on the
traffic conditions. Only use the cigarette lighter when road and traffic conditions permit.
Cigarette lighter (example)
XTurn the SmartKey to position 2in the igni-
tion lock (Ypage 123).
XTo open: open the stowage compartment
(Ypage 264).
XPress in cigarette lighter ;.
Cigarette lighter ;will pop out automatically
when the heating element is red-hot.
XTo close: push cover :of the stowage com-
partment closed.
12 V sockets
General notes
XTurn the SmartKey to position 1in the igni-
tion lock (Ypage 123). The sockets can be used for accessories with a
maximum draw of 180 W (15 A). Accessories
include such items as chargers for mobile
phones.
If you use the sockets for long periods when the
engine is switched off, the battery may dis-
charge.
An emergency cut-out ensures that the on-
board voltage does not drop too low. If the on-
board voltage is too low, the power to the sock-
ets is automatically cut. This ensures that there
is sufficient power to start the engine.
If you have connected a device to the 12 V
socket, leave the cover of the stowage com-
partment open. This prevents the cover from
being blocked.
Socket in the front center console
12 V socket (example)
XTo open:
open the stowage compartment
(Ypage 264).
XLift up the cover of socket ;.
XTo close:push cover :of the stowage com-
partment closed.
Socket in the rear compartment center
console
270Features
Stowage and features

XIf necessary, add coolant that has been tested
and approved by Mercedes-Benz.
XReplace cap:and turn it clockwise as far as
it will go.
For further information on coolant, see
(
Ypage 343).
Adding washer fluid to the windshield
washer system
GWARNING
Windshield washer concentrate could ignite if it comes into contact with hot engine compo-
nents or the exhaust system. There is a risk of
fire and injury.
Make sure that no windshield washer con-
centrate is spilled next to the filler neck.
Example: adding liquid to the windshield
washer system
XTo open: pull cap:upwards by the tab and
open.
XAdd the premixed washer fluid.
XTo close: press cap :onto the filler neck
until it engages.
If the washer fluid level drops below the recom-
mended minimum fluid level of 1.1 US qt (1.0 l),
a message appears in the multifunction display
prompting you to add washer fluid (
Ypage 239).
Further information on washer fluid
(
Ypage 344).
ASSYST PLUS
Service message
The ASSYST PLUS service interval display
informs you of the next service due date. Information on the type of service and service
intervals (see the separate Maintenance Book-
let).
Further information can be obtained at a quali-
fied specialist workshop, e.g. an authorized
Mercedes-Benz Center, or at
http://www.mbusa.com (USA only).
iThe ASSYST PLUS service interval display
does not show any information on the engine
oil level. Observe the notes on the engine oil
level (
Ypage 282).
The multifunction display shows a service mes-
sage for several seconds, e.g.:
RService A in XX Days
RService A Due
RService A Overdue by XX Days
Depending on the operating conditions of the
vehicle, the remaining time or distance until the
next service due date is displayed.
The letter A
orB, possibly in connection with a
number or another letter, indicates the type of
service. A
stands for a minor service and Bfor a
major service.
You can obtain further information from an
authorized Mercedes-Benz Center.
The ASSYST PLUS service interval display does
not take into account any periods of time during
which the battery is disconnected.
Maintaining the time-dependent service sched-
ule:
XNote down the service due date displayed in
the multifunction display before disconnect-
ing the battery.
or
XAfter reconnecting the battery, subtract the
battery disconnection periods from the ser-
vice date shown on the display.
Hiding a service message
XPress the aor% button on the steering
wheel.
Displaying service messages
XSwitch on the ignition.
XUse ò on the steering wheel to call up the
list of menus.
ASSYST PLUS285
Maintenance and care
Z

XDo not use hot water and do not wash the
vehicle in direct sunlight.
XUse a soft sponge to clean.
XUse a mild cleaning agent, such as a car
shampoo approved by Mercedes-Benz.
XThoroughly hose down the vehicle with a gen-
tle jet of water.
XDo not point the water jet directly towards the
air inlet.
XUse plenty of water and rinse out the sponge
frequently.
XRinse the vehicle with clean water and dry
thoroughly with a chamois.
XDo not let the cleaning agent dry on the paint-work.
Carefully remove all deposits of road salt as
soon as possible when driving in winter.
Power washers
GWARNING
The water jet from a circular jet nozzle (dirt
blasters) can cause invisible exterior damage
to the tires or chassis components. Compo-
nents damaged in this way may fail unexpect-
edly. There is a risk of an accident.
Do not use power washers with circular jet
nozzles to clean the vehicle. Have damaged
tires or chassis components replaced imme-
diately.
!Always maintain a distance of at least
11.8 in (30 cm) between the vehicle and the
power washer nozzle. Information about the
correct distance is available from the equip-
ment manufacturer.
Move the power washer nozzle around when
cleaning your vehicle.
Do not aim directly at any of the following:
RTires
RDoor gaps, joints etc.
RSoft top
RWind deflector net
RElectrical components
RBattery
RConnectors
RLamps
RSeals
RTrim elements
RVentilation slots
Damaged seals or electrical components can
lead to leaks or failures.
!Vehicles with decorative film: parts of your
vehicle are covered with a decorative film.
Maintain a distance of at least 27.5 in (70 cm)
between the parts of the vehicle covered with the film and the nozzle of the high pressure
cleaner.
Information abou t th
e correct distance is
available from the equipment manufacturer.
Move the power washer nozzle around when
cleaning your vehicle.
Cleaning the paintwork
!Do not affix:
Rstickers
Rfilms
Rmagnetic plates or similar items
to painted surfaces. You could otherwise
damage the paintwork.
Scratches, corrosive deposits, areas affected by
corrosion and damage caused by inadequate
care cannot always be completely repaired. In
such cases, visit a qualified specialist workshop.
XRemove dirt immediately, where possible,
while avoiding rubbing too hard.
XSoak insect remains with insect remover and
rinse off the treated areas afterwards.
XSoak bird droppings with water and rinse off
the treated areas afterwards.
XRemove coolant, brake fluid, tree resin, oils,
fuels and greases by rubbing gently with a
cloth soaked in petroleum ether or lighter
fluid.
XUse tar remover to remove tar stains.
XUse silicone remover to remove wax.
If water no longer forms "beads" on the paint
surface, use the paint care products recommen-
ded and approved by Mercedes-Benz. This is the
case approximately every three to five months,
depending on the climate conditions and the
care product used.
The cleaning product Paint Cleaner, which has
been recommended and approved by
Mercedes-Benz, shoul d b
e used when dirt has
penetrated the paint surface.
288Care
Maintenance and care

XTo remove the tire sealant bottle from the tire
inflation compressor, press together the lock-
ing tabs on the yellow cap.
XPull the tire sealant bottle out of the tire infla-
tion compressor.
The filler hose remains attached to the tire
sealant bottle.
XDrive to the nearest qualified specialist work-
shop and have the tire changed there.
XHave the tire sealant bottle and the filler hose
replaced as soon as possible at a qualified
specialist workshop.
XHave the tire sealant bottle replaced every
four years at a qualified specialist workshop.
Battery (vehicle)
12 V battery – important safety notes
Special tools and expert knowledge are required
when working on the battery, e.g. removal and
installation. You should therefore have all work
involving the battery carried out at a qualified
specialist workshop.
GWARNING
Work carried out incorrectly on the battery
can lead, for example, to a short circuit and
thus damage the vehicle electronics. This can
lead to function restrictions applying to
safety-relevant systems, e.g the lighting sys-
tem, the ABS (anti-lock braking system) or the
ESP
®(Electronic Stability Program). The oper-
ating safety of your vehicle may be restricted.
You could lose control of the vehicle, for
example:
Rwhen braking
Rin the event of abrupt steering maneuvers
and/or when the vehicle's speed is not
adapted to the road conditions
There is a risk of an accident.
In the event of a short circuit or a similar inci-
dent, contact a qualified specialist workshop
immediately. Do not drive any further. You
should have all work involving the battery car- ried out at a qualified specialist workshop. For further information about ABS and ESP
®,
see (Ypage 64) and (Ypage 67).
All vehicles except vehicles with a lithium-
ion battery:
GWARNING
Electrostatic build-up can lead to the creation of sparks, which could ignite the highly explo-
sive gases of a battery. There is a risk of an
explosion.
Before handling the battery, touch the vehicle
body to remove any existing electrostatic
build-up.
The highly flammable gas mixture forms when
charging the battery as well as when jump-start-
ing.
Always make sure that neither you nor the bat-
tery is electrostatically charged. A build-up of
electrostatic charge can be caused, for exam-
ple:
Rby wearing clothing made from synthetic
fibers
Rdue to friction between clothing and seats
Rif you push or pull the battery across the car-
pet or other synthetic materials
Rif you rub the battery with a cloth
GWARNING
During the charging process, a battery produ-
ces 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 con- tact with vehicle parts.
RNever place metal objects or tools on a bat-
tery.
RIt is important that you observe the descri-
bed 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.
Battery (vehicle)301
Breakdown assistance
Z

RIt is particularly important to observe the
described order when connecting and dis-
connecting the jumper cables.
RNever connect or disconnect the battery
terminals while the engine is running.
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.
All vehicles:
HEnvironmental note
Batteries contain dangerous
substances. It is against the
law to dispose of them with
the household rubbish. They
must be collected separately and recycled to protect the
environment.
Dispose of batteries in an
environmentally friendly
manner. Take discharged
batteries to a qualified spe-
cialist workshop or a special
collection point for used bat-
teries.
!Have the battery checked regularly at a
qualified specialist workshop.
Observe the service intervals in the Mainte-
nance Booklet or contact a qualified specialist
workshop for more information.
!Always have work on batteries carried out at
a qualified specialist workshop. Should it, in exceptional circumstances, be
absolutely necessary to disconnect the 12-
volt battery yourself, please observe the fol-
lowing:
RSecure the vehicle to prevent it from rolling
away.
RSwitch off the ignition.
RDisconnect the negative terminal first and
then the positive terminal.
The transmission is locked in position j
after disconnecting the battery.
After the work has been done, install the bat- tery and replace the cover of the positive ter-
minal clamp firmly.
Comply with safety precautions and take pro-
tective measures when handling batteries.
Risk of explosion.
Fire, open flames and smoking are
prohibited when handling the bat-
tery. Avoid creating sparks.
Electrolyte or battery acid is corro-
sive. Avoid contact with skin, eyes or
clothing.
Wear suitable protective clothing,
especially gloves, apron and face-
guard.
Immediately rinse electrolyte or acid
splashes off with clean water. Con-
tact a physician if necessary.
Wear eye protection.
Keep children away.
Observe this Operator's Manual.
For safety reasons, Mercedes-Benz recom-
mends that you only use batteries which have
been tested and approved for your vehicle by
Mercedes-Benz. These batteries provide
increased impact protection to prevent vehicle
occupants from suffering acid burns should the
battery be damaged in the event of an accident.
302Battery (vehicle)
Breakdown assistance

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
Breakdown assistance
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
Breakdown assistance
Z

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