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

XTurn the fuel filler cap counterclockwise and
remove it.
XInsert the fuel filler cap into the holder on theinside of fuel filler flap ;.
XCompletely insert the filler neck of the fuel
pump nozzle into the tank, hook in place and
refuel.
XOnly fill the tank until the pump nozzle
switches off.
Do not add any more fuel after the pump stops
filling for the first time. Otherwise, fuel may leak
out.
Closing the fuel filler flap
XReplace the cap on the filler neck and turn
clockwise until it engages audibly.
XClose the fuel filler flap.
Close the fuel filler flap before locking the vehi-
cle.
If you are driving with the fuel filler cap open, the
8 reserve fuel warning lamp flashes. A mes-
sage appears in the multifunction display
(
Ypage 227).
Problems with fuel and the fuel tank
ProblemPossible causes/consequences and MSolutions
Fuel is leaking from the
vehicle.GWARNING
The fuel line or the fuel tank is faulty.
Risk of explosion or fire.
XApply the electric parking brake.
XSwitch off the engine.
XRemove the SmartKey from the ignition lock.
or, in vehicles with KEYLESS-GO start-function or KEYLESS ‑GO
XOpen the driver's door.
The vehicle electronics are now in positionu. This is the same as
the key having been removed.
XDo not restart the engine under any circumstances.
XConsult a qualified specialist workshop.
The fuel filler flap cannot
be opened.The fuel filler flap is not unlocked.
XUnlock the vehicle (Ypage 76).
The SmartKey battery is discharged or nearly discharged.
XUnlock the vehicle using the mechanical key (Ypage 78).
The fuel filler flap is unlocked, but the opening mechanism is jammed.
XConsult a qualified specialist workshop.
Parking
Important safety notes
GWARNING
Flammable material such as leaves, grass or
twigs may ignite if they come into contact with
hot parts of the exhaust system or exhaust
gas flow. There is a risk of fire.
Park the vehicle so that no flammable mate-
rials come into contact with parts of the vehi-
cle which are hot. Take particular care not to
park on dry grassland or harvested grain
fields.
Parking143
Driving and parking
Z

GWARNING
If you leave children unsupervised in the vehi-
cle, they could set it in motion by, for example:
Rrelease the parking brake.
Rshift the automatic transmission out of the
parking position P.
Rstart the engine.
In addition, they may operate vehicle equip-
ment and become trapped. There is a risk of
an accident and injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children unsupervised in the vehicle.
!Always secure the vehicle correctly against
rolling away. Otherwise, the vehicle or its driv-
etrain could be damaged.
To ensure that the vehicle is secured against
rolling away unintentionally:
Rthe electric parking brake must be applied.
Rthe transmission must be in position jand
the SmartKey must be removed from the igni-
tion lock.
Rthe front wheels must be turned towards the
curb on steep uphill or downhill gradients.
Rthe empty vehicle must be secured at the
front axle with a wheel chock or similar, for
example, on uphill or downhill gradients.
Ron uphill or downhill gradients the laden vehi- cle must also be secured at the rear axle, for
example with a wheel chock or similar object.
Switching off the engine
Important safety notes
GWARNING
The automatic transmission switches to neu-
tral position Nwhen you switch off the engine.
The vehicle may roll away. There is a risk of an
accident.
After switching off the engine, always switch
to parking position P. Prevent the parked vehi-
cle from rolling away by applying the parking
brake.
Vehicles with automatic transmission
XApply the electric parking brake.
XShift the transmission to position j.
XWith the SmartKey:turn the SmartKey to
position uin the ignition lock and remove it.
The immobilizer is activated.
XWith the Start/Stop button: press the
Start/Stop button (Ypage 124).
The engine stops and all the indicator lamps in
the instrument cluster go out.
When the driver's door is closed, this corre-
sponds to key position 1. When the driver's
door is open, this corresponds to key position
u, "Key removed".
If you switch the engine off with the transmis-
sion in position korh the automatic trans-
mission shifts to iautomatically.
With the SmartKey: if you then open the driv-
er's door or the front-passenger door or remove the SmartKey from the ignition, the automatic
transmission shifts to jautomatically.
With the Start/Stop button: if you then open
the driver's door or the front-passenger door,
the automatic transmission shifts to jauto-
matically.
If you want the automatic transmission to
remain in neutral i, for example, when having
the vehicle cleaned in an automatic car wash
with a towing system:
XVehicles with KEYLESS-GO or KEYLESS-
GO start function: remove the Start/Stop
button from the ignition lock.
XInsert the SmartKey into the ignition lock.
XAll vehicles: switch the ignition on.
XDepress the brake pedal and keep it
depressed.
XEngage neutral i.
XRelease the brake pedal.
XRelease the electric parking brake.
XSwitch off the ignition and leave the SmartKey
in the ignition lock.
The engine can be switched off in an emergency
while the vehicle is in motion by pressing and
holding the Start/Stop button for three sec-
onds. This function operates independently of
the ECO start/stop automatic engine switch-off function.
144Parking
Driving and parking

Electric parking brake
General notes
GWARNING
If you leave children unsupervised in the vehi-
cle, they could set it in motion by, for example:
Rrelease the parking brake.
Rshift the automatic transmission out of the
parking position P.
Rstart the engine.
In addition, they may operate vehicle equip-
ment and become trapped. There is a risk of
an accident and injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children unsupervised in the vehicle.
The function of the electric parking brake is
depending on the on-board voltage. If the on-
board voltage is low or there is a malfunction in
the system, it may not be possible to apply the
released parking brake.
XIf this happens, park the vehicle on level
ground only and secure it to prevent it from
rolling away.
XShift the transmission to position j.
It may not be possible to release an applied
parking brake if the on-board voltage is low or
there is a malfunction in the system. Contact a
qualified specialist workshop.
The electric parking brake performs a function
test at regular intervals while the engine is
switched off. The sounds that can be heard while
this is occurring are normal.
Applying or releasing manually
XTo apply: push handle :.
When the electric parking brake is applied,
the red F(USA only) or !(Canada
only) indicator lamp lights up in the instru-
ment cluster.
The electric parking brake can also be applied
when the SmartKey is removed.
XTo release: pull handle:.
The red F(USA only) or !(Canada
only) indicator lamp in the instrument cluster goes out.
The electric parking brake can only be released:
Rif the SmartKey is in position 1or2 in the
ignition lock (Ypage 123) or
Rif the ignition was switched on using the
Start/Stop button
Applying automatically
The electric parking brake is automatically
applied when the transmission is in position j
and:
Rthe engine is switched off or
Rthe driver is not wearing a seat belt and the
driver's door is opened
To prevent the electric parking brake from being
automatically applied, pull handle :.
The electric parking brake is also engaged auto-
matically if:
RDistance Pilot DISTRONIC brings the vehicle
to a standstill or
Rthe HOLD function is keeping the vehicle sta- tionary
RParking Pilot is keeping the vehicle stationary
In addition, at least one of the following condi-
tions must be fulfilled:
Rthe engine is switched off
Rthe driver is not wearing a seat belt and the
driver's door is opened
Rthere is a system malfunction
Rthe power supply is insufficient
Rthe vehicle is stationary for a lengthy period
The red F(USA only) or !(Canada only)
indicator lamp in the instrument cluster goes
out.
The electric parking brake is not automatically
engaged if the engine is switched off by the ECO
start/stop function.
Parking145
Driving and parking
Z

Releasing automatically
Your vehicle's electric parking brake is auto-
matically released if all of the following condi-
tions are met:
Rthe seat belt has been fastened
Rthe engine is running
Rthe transmission is in positionhork and
you accelerate.
or
you shift from transmission position jto
position hork. On steep inclines, you have
to press the accelerator as well.
If the transmission is in position k, the trunk lid
must be closed.
If your seat belt is not fastened, the following
conditions must be fulfilled to automatically
release the electric parking brake:
Rthe driver's door is closed
RYou have shifted out of transmission position
j or you have previously driven faster than
2 mph (3 km/h).
Ensure that you do not depress the accelerator
pedal unintentionally. Otherwise, the parking
brake will be released and the vehicle will start
to move.
Emergency braking
The vehicle can also be braked during an emer- gency by using the electric parking brake.
XWhile driving, push handle :of the electric
parking brake (Ypage 145).
The vehicle is braked as long as you keep
handle :of the electric parking brake
depressed. The longer electric parking brake
handle :is depressed, the greater the brak-
ing force.
During braking:
Ra warning tone sounds
Rthe Please Release Parking Brakemes-
sage appears
Rthe red F(USA only) or !(Canada
only) indicator lamp in the instrument cluster
flashes
When the vehicle has been braked to a stand-
still, the electric parking brake is engaged.
Parking the vehicle for a long period
If you leave the vehicle parked for longer than
four weeks, the battery may be damaged by
exhaustive discharging.
If you leave the vehicle parked for longer than six
weeks, the vehicle may suffer damage as a
result of lack of use.
XVisit a qualified specialist workshop and seek
advice.
iYou can obtain information about trickle
chargers from a qualified specialist work-
shop.
Driving tips
General driving tips
Important safety notes
GWARNING
If you switch off the ignition while driving,
safety-relevant functions are only available
with limitations, or not at all. This could affect, for example, the power steering and the brake
boosting effect. You will require considerably
more effort to steer and brake. There is a risk
of an accident.
Do not switch off the ignition while driving.
GWARNING
If you operate mobile communication equip-
ment when driving, you may be distracted
from the traffic situation. You could also lose
control of the vehicle. There is a risk of an
accident.
Only operate this equipment when the vehicle
is stationary.
Observe the legal requirements for the country
in which you are driving. Some jurisdictions pro-
hibit the driver from using a mobile phone while driving a vehicle.
If you make a call while driving, always use
hands-free mode. Only operate the telephone
when the traffic situation permits. If you are
unsure, pull over to a safe location and stop
before operating the telephone.
146Driving tips
Driving and parking

Bear in mind that at a speed of only 30 mph
(approximately 50 km/h), the vehicle covers a
distance of 44 ft (approximately 14m)per sec-
ond.
Drive sensibly – save fuel
Observe the following tips to save fuel:
XThe tires should always be inflated to the rec-
ommended tire pressure.
XRemove unnecessary loads.
XRemove roof racks when they are not needed.
XWarm up the engine at low engine speeds.
XAvoid frequent acceleration or braking.
XHave all maintenance work carried out as
indicated by the service intervals in the Main-
tenance Booklet or by the service interval dis-
play.
Fuel consumption also increases when driving in cold weather, in stop-start traffic and in hilly ter-
rain.
Drinking and driving
GWARNING
Drinking and driving and/or taking drugs and driving are very dangerous combinations.
Even a small amount of alcohol or drugs can
affect your reflexes, perceptions and judg-
ment.
The possibility of a serious or even fatal acci-
dent is greatly increased when you drink or
take drugs and drive.
Do not drink or take drugs and drive or allow
anyone to drive who has been drinking or tak-
ing drugs.
Emission control
GWARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Inhaling
these exhaust gases leads to poisoning. There
is a risk of fatal injury. Therefore never leave
the engine running in enclosed spaces with-
out sufficient ventilation. Certain engine systems are designed to keep
the level of poisonous components in exhaust
fumes within legal limits.
These systems only work at peak efficiency if
they are serviced exactly in accordance with the
manufacturer's specifications. Always have
work on the engine carried out at a qualified
specialist workshop. Mercedes-Benz recom-
mends 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.
The engine settings must not be changed under any circumstances. Furthermore, all specific
service work must be carried out at regular
intervals and in accordance with the Mercedes-
Benz service requirements. Details can be found in the Maintenance Booklet.
ECO display
The ECO display shows you how economical
your driving style is. The ECO display assists you
in achieving the most economical driving style
for the selected settings and prevailing condi-
tions. Your driving style can significantly influ-
ence the vehicle's consumption.
:Acceleration
;Coasting
=Constant
?Additional range achieved
Range ?is shown under Bonus
fr.Startand
represents the additional range achieved since
the beginning of the journey as a result of an
adapted driving style.
If the fuel level has dropped into the reserve
range, the Reserve Fuel
display message is
shown instead of range ?in the multifunction
Driving tips147
Driving and parking
Z

display. The8warning lamp in the instru-
ment cluster also lights up (Ypage 247).
The ECO display consists of three sections, with
an inner and outer area. The sections corre-
spond to the following three categories:
:Acceleration (evaluation of all accel-
eration processes):
Rthe outer area fills up and the inner area lights up green: moderate
acceleration, especially at higher
speeds
Rthe outer area empties and the
inner area is gray: sporty acceler-
ation
;Coasting (evaluation of all decelera-
tion processes):
Rthe outer area fills up and the inner area lights up green: anticipatory
driving, keeping your distance and
early release of the accelerator.
The vehicle can coast without use
of the brakes.
Rthe outer area empties and the
inner area is gray: frequent heavy
braking
=Constant (continuous evaluation
over the entire journey):
Rthe outer area fills up and the inner area lights up green: constant
speed and avoidance of unneces-
sary acceleration and deceleration
Rthe outer area empties and the
inner area is gray: fluctuations in
speed
The three inner areas display the current driving
style and light up green as a result of a particu-
larly economical driving style. Depending on thedriving situation, up to two areas may light up
simultaneously.
At the beginning of the journey, the three outer
areas are empty and fill up as a result of eco-
nomical driving. A higher level indicates a more
economical driving style. If the three outer areas
are completely filled at the same time, the driver
has adopted the most economical driving style
for the selected settings and prevailing condi-
tions. The ECO display border lights up.
The ECO display does not indicate the actual fuel consumption. The additionally achieved range displayed under
Bonus fr. Start
does not
indicate a fixed consumption reduction.
In addition to driving style, the actual consump-
tion is affected by other factors, such as:
Rload
RTire pressure
RCold start
RChoice of route
RActive electrical consumers
These factors are not included in the ECO dis-
play.
An economical driving style specially requires
driving at moderate engine speeds.
Achieving a higher value in the categories
"Acceleration" and "Constant":
Robserve the gearshift recommendations
Rdrive using drive program E
On long journeys at a constant speed, e.g. on the
highway, only the outer area for "constant" will
change.
The ECO display summarizes the driving style
from the start of the journey to its completion.
Therefore, there are more marked changes in
the outer areas at the start of a journey. On lon- ger journeys, there are fewer changes. For more
marked changes, perform a manual rest
(
Ypage 198).
For further information on the ECO display, see
(
Ypage 197).
Braking
Important safety notes
GWARNING
If you shift down on a slippery road surface in an attempt to increase the engine's braking
effect, the drive wheels could lose their grip.
There is an increased danger of skidding and
accidents.
Do not shift down for additional engine brak-
ing on a slippery road surface.
Downhill gradients
!On long and steep gradients, you must
reduce the load on the brakes by shifting to a
lower gear in good time. This allows you to
take advantage of the engine's braking effect.
148Driving tips
Driving and parking

This helps you to avoid overheating the
brakes and wearing them out excessively.
When you take advantage of engine braking, a
drive wheel may not turn for some time, e.g.
on a slippery road surface. This could cause
damage to the drive train. This type of damage is not covered by the Mercedes-Benz war-
ranty.
Heavy and light loads
GWARNING
If you rest your foot on the brake pedal while
driving, the braking system can overheat. This increases the stopping distance and can even
cause the braking system to fail. There is a
risk of an accident.
Never use the brake pedal as a footrest. Never
depress the brake pedal and the accelerator
pedal at the same time.
!Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
If the brakes have been subjected to a heavy
load, do not stop the vehicle immediately. Drive
on for a short while. This allows the airflow to
cool the brakes more quickly.
Wet roads
If you have driven for a long time in heavy rain
without braking, there may be a delayed reac-
tion from the brakes when braking for the first
time. This may also occur after the vehicle has
been washed or driven through deep water.
You have to depress the brake pedal more
firmly. Maintain a greater distance from the
vehicle in front.
After driving on a wet road or having the vehicle
washed, brake firmly while paying attention to
the traffic conditions. This will warm up the
brake discs, thereby drying them more quickly
and protecting them against corrosion.
Limited braking performance on salt-
treated roads
If you drive on salted roads, a layer of salt resi-
due may form on the brake discs and brake
pads. This can result in a significantly longer
braking distance.
RIn order to prevent any salt build-up, apply the
brakes occasionally while paying attention to
the traffic conditions.
RCarefully depress the brake pedal and the
beginning and end of a journey.
RMaintain a greater distance to the vehicle
ahead.
Servicing the brakes
!The brake fluid level may be too low, if:
Rif the red brake warning lamp lights up in
the instrument cluster and
Ryou hear a warning tone while the engine is
running
Observe additional warning messages in the
multifunction display.
The brake fluid level may be too low due to
brake pad wear or leaking brake lines.
Have the brake system checked immediately.
Consult a qualified specialist workshop to
arrange this.
!Vehicles with 4MATIC: function or per-
formance tests may only be carried out on a 2-
axle dynamometer. If you wish to operate the
vehicle on such a dynamometer, please con-
sult a qualified specialist workshop in
advance. You could otherwise damage the
drive train or the brake system.
!Vehicles with 4MATIC: the ESP®system
operates automatically. If the electric parking
brake is tested on a brake dynamometer, the
engine and ignition must be switched off: turn
the SmartKey in the ignition lock to position
u or1 or press the Start/Stop button
repeatedly in accordance with the given
SmartKey positions.
Braking triggered automatically by ESP
®may
cause severe damage to the brake system.
All checks and maintenance work on the brake
system must be carried out at a qualified spe-
cialist workshop.
Have brake pads installed and brake fluid
replaced at a qualified specialist workshop.
If the brake system has only been subject to
moderate loads, you should test the functional-
ity of your brakes at regular intervals.
Information on BAS (Brake Assist System)
(
Ypage 65) and Active Brake Assist with cross-
traffic function (Ypage 71).
Driving tips149
Driving and parking
Z

For safety reasons, Mercedes-Benz recom-
mends only installing the following brake disks
and brake pads/linings:
Rbrake disks that have been approved by
Mercedes-Benz
Rbrake pads/linings that have been approved
by Mercedes-Benz or that are of an equivalent
standard of quality
Other brake disks or brake pads/linings can
compromise the safety of your vehicle.
Always replace all brake disks and brake pads/
linings on an axle at the same time. Always
install new brake pads/linings when replacing
brake disks.
The vehicle is equipped with lightweight brake
disks to which the wheel assembly with rim and
threaded connection is matched.
The use of brake disks other than those
approved by Mercedes-Benz can change the
track width and is subject to approval, if appli-
cable.
Shock-type loads when handling the brake
discs, such as when changing wheels, can lead
to a reduction in comfort when driving with light-
weight brake discs. Avoid shock-type loads on
the lightweight brake disks, particularly on the
brake plate.
Mercedes-Benz recommends that you only use
brake fluid that has been specially approved for
your vehicle by Mercedes-Benz, or which corre-
sponds to an equivalent quality standard. Brake
fluid which has not been approved for
Mercedes-Benz vehicles or which is not of an
equivalent quality could affect your vehicle's
operating safety.
High-performance and ceramic brakes
(Mercedes-AMG vehicles)
The AMG brake systems are designed for heavy
loads. This may lead to noise when braking. This
will depend on:
RSpeed
RBraking force
REnvironmental conditions, such as tempera-
ture and humidity
The wear of individual components of the brake
system, such as the brake pads/linings or brake
discs, depends on the individual driving style
and operating conditions.
For this reason, it is impossible to state a mile-
age that will be valid under all circumstances. An aggressive driving style will lead to high wear.
You can obtain more information on this from a
qualified specialist workshop.
New and replaced brake pads and discs only
reach their optimum braking effect after several
hundred kilometers of driving. Compensate for
this by applying greater force to the brake pedal.
Keep this in mind, and adapt your driving and
braking accordingly during this break-in period.
Excessive heavy braking results in correspond-
ingly high brake wear. If the brake pads/linings
have reached their wear limit, the multifunction
display shows a corresponding message. Espe-
cially for high performance driving, it is impor-
tant to maintain and have the brake system
checked regularly.
Driving on wet roads
Hydroplaning
If water has accumulated to a certain depth on
the road surface, there is a danger of hydro-
planing occurring, even if:
Ryou drive at low speeds
Rthe tires have adequate tread depth
For this reason, in the event of heavy rain or in
conditions in which hydroplaning may occur,
you must drive in the following manner:
Rlower your speed
Ravoid ruts
Ravoid sudden steering movements
Rbrake carefully
Driving on flooded roads
!Bear in mind that vehicles traveling in front
or in the opposite direction create waves. This
may cause the maximum permissible water
depth to be exceeded.
Failure to observe these notes may result in
damage to the engine, electrical systems and
transmission.
If you have to drive on stretches of road on which
water has collected, please bear in mind that:
Rin the case of standing water, the water level may be no higher than the lower edge of the
vehicle body
Ryou should drive no faster than walking pace
150Driving tips
Driving and parking