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

Drive program ................................ 136
Drive program display .................... 134
Driving tips .................................... 135
DYNAMIC SELECT switch .............. 130
Emergency running mode .............. 141
Engaging drive position .................. 134
Engaging neutral ............................ 133
Engaging park position automati-
cally ............................................... 133
Engaging reverse gear ................... 133
Engaging the park position ............ 133
Gearshift recommendation ............ 140
Gliding mode ................................. 136
Kickdown ....................................... 136
Manual shifting .............................. 138
Oil temperature (on-board com-
puter, Mercedes-AMG vehicles) ..... 208
Overview ........................................ 132
Permanent setting ......................... 139
Problem (malfunction) ................... 141
Pulling away ................................... 126
Starting the engine ........................ 125
Steering wheel paddle shifters ...... 138
Transmission position display
(DIRECT SELECT lever) ................... 134
Transmission positions .................. 135
Automatic transmission emer-
gency mode ....................................... 141
B
Back button ....................................... 254
Backup lamp
Display message ............................ 224
BAS (Brake Assist System) ................. 65
Basic settings
see Settings
Battery (SmartKey)
Checking .......................................... 79
Important safety notes .................... 78
Replacing ......................................... 79
Battery (vehicle)
Charging ........................................ 303
Display message ............................ 226
Important safety notes .................. 301
Jump starting ................................. 304
Belt
see Seat belts Belt warning
......................................... 48
Blind Spot Assist
Activating/deactivating (on-
board computer) ............................ 205
Display message ............................ 230
Notes/function .............................. 182
see Active Blind Spot Assist
Blower
see Climate control
Bluetooth
®
Connecting a different mobile
phone ............................................ 261
Searching for a mobile phone ........ 260
see also Digital Operator's Man-
ual .................................................. 253
Telephony ...................................... 260
Brake
Active Brake Assist with cross-
traffic function ................................. 71
Brake Assist
see BAS (Brake Assist System)
Brake assistance
see BAS (Brake Assist System)
Brake fluid
Display message ............................ 218
Notes ............................................. 343
Brake force distribution
see EBD (electronic brake force
distribution)
Brake linings
Display message ............................ 218
Brakes
ABS .................................................. 64
Adaptive Brake Assist ...................... 67
BAS .................................................. 65
Brake fluid (notes) ......................... 343
Display message ............................ 213
EBD .................................................. 71
High-performance brake system .... 150
Hill start assist ............................... 127
HOLD function ............................... 161
Important safety notes .................. 148
Maintenance .................................. 149
Parking brake ................................ 145
Riding tips ...................................... 148
Warning lamp ................................. 243
Breakdown
Where will I find...? ........................ 295
6Index

Adjusting the 4-way lumbar sup-
port .................................................. 98
Adjusting the head restraint ............ 96
Calling up a stored setting (mem-
ory function) .................................. 106
Cleaning the cover ......................... 294
Folding the backrest (rear com-
partment) forwards/back .............. 265
Folding the backrests forward/
back ................................................. 97
Important safety notes .................... 94
Seat backrest display message ..... 238
Seat heating .................................... 99
Seat heating problem .................... 100
Seat ventilation ................................ 99
Seat ventilation problem ................ 100
Storing settings (memory func-
tion) ............................................... 106
Switching AIRSCARF on/off .......... 100
Securing a load
see Securing cargo
Securing cargo .................................. 266
Selecting a gear
see Automatic transmission
Selector lever
Cleaning ......................................... 293
see Automatic transmission
Sensors (cleaning instructions) ....... 292
Service center
see Qualified specialist workshop
Service Center
see Qualified specialist workshop
Service menu (on-board com-
puter) .................................................. 203
Service message
see ASSYST PLUS
Service products
Brake fluid ..................................... 343
Coolant (engine) ............................ 343
Engine oil ....................................... 342
Fuel ................................................ 340
Important safety notes .................. 340
Refrigerant (air-conditioning sys-
tem) ............................................... 344
Washer fluid ................................... 344
Setting the date/time format
see also Digital Operator's Man-
ual .................................................. 253 Setting the language
see also Digital Operator's Man-
ual .................................................. 253
Setting the time
see also Digital Operator's Man-
ual .................................................. 253
Se

ttings
Factory (on-board computer) ......... 207
On-board computer ....................... 203
SETUP (on-board computer,
Mercedes-AMG vehicles) .................. 209
Side impact air bag ............................. 50
Side marker lamp (display mes-
sage) ................................................... 224
Side windows
Cleaning ......................................... 291
Important safety information ........... 85
Opening/closing .............................. 86
Opening/closing (all) ....................... 86
Problem (malfunction) ..................... 87
Resetting ......................................... 87
Reversing feature ............................. 85
SIRIUS services
see also Digital Operator's Man-
ual .................................................. 253
SmartKey
Changing the battery ....................... 79
Changing the programming ............. 78
Checking the battery ....................... 79
Display message ............................ 240
Door central locking/unlocking ....... 76
Important safety notes .................... 76
KEYLESS-GO start function .............. 77
Loss ................................................. 80
Mechanical key ................................ 78
Opening/closing soft top ................. 90
Overview .......................................... 76
Positions (ignition lock) ................. 123
Problem (malfunction) ..................... 80
Starting the engine ........................ 125
Smartphone
Starting the engine ........................ 126
SMS
see also Digital Operator's Man-
ual .................................................. 253
Snow chains ...................................... 315
Socket (12 V)
Center console .............................. 270
Index19

Up to a speed of approximately 44 mph
(70 km/h) the Active Brake Assist with cross-
traffic function assists you with braking in haz-
ardous situations with:
Rstationary obstacles in the path of the vehicle,
e.g. stopped or parked vehicles
Rstationary pedestrians in the path of the vehi-
cle
Robstacles crossing your path that move in the
detection range of the sensors and are detec-
ted
XKeep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
You can prevent the intervention of Active Brake
Assist with cross-traffic function at any time by:
Rdepressing the accelerator pedal further.
Ractivating kickdown.
Rreleasing the brake pedal
The braking application of Active Brake Assist
with cross-traffic function is ended automati-
cally if:
Ryou maneuver to avoid the obstacle.
Rthere is no longer a risk of collision.
Ran obstacle is no longer detected in front of
your vehicle.
STEER CONTROL
General information
STEER CONTROL helps you by transmitting a
noticeable steering force to the steering wheel
in the direction required for vehicle stabilization.
This steering assistance is provided in particular
if:
Rboth right wheels or both left wheels are on a
wet or slippery road surface when you brake
Rthe vehicle begins to skid
Important safety notes
iObserve the "Important safety notes" sec-
tion (Ypage 64). No steering support is provided from STEER
CONTROL, if:
RESP®is deactivated
RESP®is malfunctioning
Rthe steering is malfunctioning
If ESP®is malfunctioning, you will be assisted
further by the electrical power steering.
Protection against theft
Immobilizer
The immobilizer prevents your vehicle from
being started without the correct SmartKey.
XTo activate with the SmartKey: remove the
SmartKey from the ignition lock.
XTo activate with KEYLESS-GO start-func-
tion or KEYLESS-GO: switch the ignition off
and open the driver's door.
XTo deactivate: switch on the ignition.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Anyone
can start the engine if a valid SmartKey has been
left inside the vehicle.
iThe immobilizer is always deactivated when
you start the engine.
In the event that the engine cannot be started
(yet the vehicle's battery is charged), the sys- tem is not operational. Contact an authorized
Mercedes-Benz Center or call
1-800-FOR-MERCedes (in the USA) or
1-800-387-0100 (in Canada).
ATA (anti-theft alarm system)
74Protection against theft
Safety

multimedia system; see the Digital Operator's
Manual.
You will receive visual and acoustic locking con-
firmation if all components were able to be
locked.
When the locator lighting is activated via the
multimedia system, it lights up when it is dark
after the vehicle is unlocked with the SmartKey;
see the Digital Operator's Manual.
XTo open the trunk lid automatically from
outside the vehicle:press and hold theF
button until the trunk lid opens.
KEYLESS-GO
General notes
Bear in mind that the engine can be started by
any of the vehicle occupants if there is a Smart-
Key in the vehicle (
Ypage 125).
Locking/unlocking centrally
You can start, lock or unlock the vehicle using
KEYLESS-GO. To do this, you only need carry the
SmartKey with you. You can combine the func-
tions of KEYLESS-GO with those of a conven-
tional SmartKey. Unlock the vehicle by using
KEYLESS-GO, for instance, and lock it using the
& button on the SmartKey.
The driver's door and the door at which the han-
dle is used, must both be closed. The SmartKey
must be outside the vehicle. When locking or
unlocking with KEYLESS-GO, the distance
between the SmartKey and the corresponding
door handle must not be greater than 3 ft (1 m).
A brief radio connection between the vehicle
and the SmartKey determines whether a valid
SmartKey is in, or in the direct vicinity of, the
vehicle. This occurs, for example:
Rwhen starting the engine
Rwhile driving
Rwhen the external door handles are touched
Rduring convenience closing
XTo unlock the vehicle: touch the inner sur-
face of the door handle.
XTo lock the vehicle: touch sensor surface :
or ;.
Make sure that you do not touch the inner
surface of the door handle.
XConvenience closing feature: touch
recessed sensor surface ;for an extended
period.
Deactivating and activating
If you do not intend to use a SmartKey for an
extended period of time, you can deactivate the
KEYLESS-GO function of the SmartKey. The
SmartKey will then use very little power, thereby
conserving battery power. For the purposes of
activation/deactivation, the vehicle must not be
nearby.
XTo deactivate: press the&button on the
SmartKey twice in rapid succession.
The battery check lamp (
Ypage 79) of the
SmartKey flashes twice briefly and lights up
once, then KEYLESS-GO is deactivated.
XTo activate: press any button on the Smart-
Key.
or
XInsert the SmartKey into the ignition lock.
KEYLESS-GO and all of its associated features
are available again.
KEYLESS-GO start function
General notes
Bear in mind that the engine can be started by
any of the vehicle occupants if there is a Smart-
Key in the vehicle (
Ypage 125).
SmartKey77
Opening and closing
Z

Changing the settings of the locking
system
You can change the settings of the locking sys-
tem. This means that only the driver's door and
the fuel filler flap are unlocked when the vehicle
is unlocked. This is useful if you frequently travel
alone.
XTo change the setting:press and hold down
the % and& buttons simultaneously
for approximately six seconds until the bat-
tery check lamp (
Ypage 79) flashes twice.
If the setting of the locking system is changed
within the signal range of the vehicle, pressing
the & or% button:
Rlocks or
Runlocks the vehicle
The SmartKey now functions as follows:
XTo unlock: press the%button once.
XTo unlock centrally: press the%button
twice.
XTo lock: press the &button.
XTo restore the factory settings: press and
hold the %and& buttons simultane-
ously for approximately six seconds until the
battery check lamp (
Ypage 79) flashes
twice.
The KEYLESS-GO functions can be changed as
follows:
XTo unlock the driver's door: touch the inner
surface of the door handle on the driver's
door.
XTo unlock centrally: touch the inner surface
of the front-passenger door handle.
XTo lock centrally: touch the outer sensor
surface on one of the door handles.
Mechanical key
General notes
If the vehicle can no longer be locked or
unlocked with the SmartKey or KEYLESS-GO,
use the mechanical key.
If you use the mechanical key to unlock and
open the driver's door, the anti-theft alarm sys-
tem will be triggered. Switch off the alarm
(
Ypage 74). If you unlock the vehicle using the mechanical
key, the fuel filler flap will not be unlocked auto-
matically.
XTo unlock the fuel filler flap:
insert the
SmartKey into the ignition lock.
Removing the mechanical key
XPush release catch :in the direction of the
arrow and at the same time remove mechan- ical key ;from the SmartKey.
Further information on locking/unlocking the
driver's door (
Ypage 83).
Inserting the mechanical key
XPush mechanical key ;completely into the
SmartKey until it engages and release
catch :is back in its basic position.
SmartKey battery
Important safety notes
GWARNING
Batteries contain toxic and corrosive substan- ces. If batteries are swallowed, it can result in
severe health problems. There is a risk of fatalinjury.
Keep batteries out of the reach of children. If
a battery is swallowed, seek medical attention
immediately.
HEnvironmental note
Batteries contain dangerous
substances. It is against the
law to dispose of them with
78SmartKey
Opening and closing

the household rubbish. They
must be collected separatelyand 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.
The SmartKey batteries contain perchlorate
material, which may require special handling
and regard for the environment. National guide-
lines must be observed during disposal. In Cal-
ifornia, see www.dtsc.ca.gov/
HazardousWaste/Perchlorate/index.cfm .
Mercedes-Benz recommends that you have the
batteries replaced at a qualified specialist work-
shop.
Checking the battery
XPress the &or% button.
The battery is working properly if battery
check lamp :lights up briefly.
The battery is discharged if battery check
lamp :does not light up briefly.
XChange the battery (Ypage 79).
If the SmartKey battery is checked within the
signal reception range of the vehicle, pressing
the & or% button:
Rlocks or
Runlocks the vehicle
iYou can get a battery at any qualified spe-
cialist workshop.
Replacing the battery
You require a CR 2025 3 V cell battery.
XTake the mechanical key out of the SmartKey
(Ypage 78).
XPress mechanical key ;into the SmartKey
opening in the direction of the arrow until bat-
tery compartment cover :opens. Do not
hold battery compartment cover :closed
while doing so.
XRemove battery compartment cover :.
XRepeatedly tap the SmartKey against your
palm until battery=falls out.
XInsert the new battery with the positive ter-
minal facing upwards. Use a lint-free cloth to
do so.
XMake sure that the surface of the battery is
free of lint, grease and other contaminants.
XInsert the front tabs of battery compartment
cover :into the housing first and then press
to close it.
XInsert mechanical key ;into the SmartKey
(Ypage 78).
XCheck the function of all SmartKey buttons on
the vehicle.
SmartKey79
Opening and closing
Z

Problems with the SmartKey
ProblemPossible causes/consequences andMSolutions
You can no longer lock or
unlock the vehicle using
the SmartKey.The SmartKey battery is discharged or nearly discharged.
XCheck the SmartKey battery (Ypage 79) and replace it if necessary
(Ypage 79).
If this does not work:
XLock or unlock the vehicle using the mechanical key (Ypage 83).
There is interference from a powerful source of radio waves.
XLock or unlock the vehicle using the mechanical key (Ypage 83).
The SmartKey is faulty.
XLock or unlock the vehicle using the mechanical key (Ypage 83).
XHave the SmartKey checked at a qualified specialist workshop.
You can no longer lock or
unlock the vehicle using
KEYLESS-GO.KEYLESS-GO was deactivated.
XReactivate KEYLESS-GO (Ypage 77).
The SmartKey battery is discharged or nearly discharged.
XCheck the SmartKey battery (Ypage 79) and replace it if necessary
(Ypage 79).
If this does not work:
XLock or unlock the vehicle using the mechanical key (Ypage 83).
There is interference from a powerful source of radio waves.
XLock or unlock the vehicle using the mechanical key (Ypage 83).
KEYLESS-GO is malfunctioning.
XLock/unlock the vehicle using the remote control function of the
SmartKey.
XHave the vehicle and SmartKey checked at a qualified specialist
workshop.
If the vehicle can also not be locked/unlocked using the remote con-
trol function:
XLock or unlock the vehicle using the mechanical key (Ypage 83).
XHave the vehicle and SmartKey checked at a qualified specialist
workshop.
The engine cannot be
started using the Smart-
Key.The on-board voltage is too low.
XSwitch off non-essential consumers, e.g. seat heating or interior
lighting, and try to start the engine again.
If this does not work:
XCheck the starter battery and charge it if necessary (Ypage 303).
or
XJump-start the vehicle (Ypage 304).
or
XConsult a qualified specialist workshop.
80SmartKey
Opening and closing

ProblemPossible causes/consequences andMSolutions
The engine cannot be
started using the Start/
Stop button. The Smart-
Key is in the vehicle.The vehicle is locked.
XUnlock the vehicle and try to start the vehicle again.
The SmartKey battery is discharged or nearly discharged.
XCheck the SmartKey battery (Ypage 79) and replace it if necessary
(Ypage 79).
If this does not work:
XStart your vehicle with the SmartKey in the ignition lock.
There is interference from a powerful source of radio waves.
XStart your vehicle with the SmartKey in the ignition lock.
You have lost a Smart-
Key.XHave the SmartKey deactivated at a qualified specialist workshop.
XReport the loss immediately to the vehicle insurers.
XIf necessary, have the locks changed as well.
You have lost the
mechanical key.XReport the loss immediately to the vehicle insurers.
XIf necessary, have the locks changed as well.
Doors
Important safety notes
GWARNING
If children are left unsupervised in the vehicle,
they could:
Ropen the doors, thus endangering other
people or road users.
Rget out and disrupt traffic.
Roperate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they:
Rrelease the parking brake.
Rshifting the automatic transmission out of
park position P
RStart the engine.
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 or animals unattended in the
vehicle. Always keep the SmartKey out of
reach of children.
Unlocking and opening doors from
the inside
When a door is opened, the side window on that side opens slightly. When the door is closed, the
side window closes again.
!The side windows will not open/close if the
battery is discharged or if the side windows
have iced up. It will then not be possible to
close the door. Do not attempt to force the
door closed. You could otherwise damage the
door or the side window.
You can open a door from inside the vehicle
even if it has been locked. If the vehicle has been
locked with the SmartKey or with KEYLESS-GO,
opening a door from the inside will trigger the
anti-theft alarm system. Switch off the alarm
(
Ypage 74).
Doors81
Opening and closing
Z

Switching the seat heating on/off
Switching on/off
GWARNING
Repeatedly switching on the seat heating can
cause the seat cushion and backrest pads to
become very hot. The health of persons with
limited temperature sensitivity or a limited
ability to react to high temperatures may be
affected or they may even suffer burn-like
injuries. There is a risk of injury.
Therefore, do not switch the seat heating on
repeatedly.
The three red indicator lamps in the button indi-
cate the heating level you have selected.
The system automatically switches down from
level 3to level 2after approximately eight
minutes.
The system automatically switches down from
level 2to level 1after approximately ten
minutes.
The system automatically switches off approx-
imately 20 minutes after it is set to level 1.
XTurn the SmartKey to position1or2 in the
ignition lock (Ypage 123).
XTo switch on: press button:repeatedly
until the desired heating level is set.
XTo switch off: press button:repeatedly
until all the indicator lamps go out.
iIf the battery voltage is too low, the seat
heating may switch off.
iIf drive program Eis selected, the power of
the seat heating is reduced.
Switching the seat ventilation on/off
Switching on/off
The blue indicator lamps in the button indicate
the ventilation level you have selected.
XTurn the SmartKey to position 1or2 in the
ignition lock (Ypage 123).
XTo switch on: press button:repeatedly
until the desired ventilation level is set.
XTo switch off: press button:repeatedly
until all the indicator lamps go out.
iIf the battery voltage is too low, the seat
ventilation may switch off.
iYou can open the side windows and the soft
top with the SmartKey (Ypage 90). The seat
ventilation of the driver's seat automatically
switches to the highest level.
iWhen the vehicle is stationary, the fan
speed can be reduced automatically. This
reduces the noises of the seat ventilation.
Seats99
Seats, steering wheel and mirrors
Z

Problems with the seat heating / seat ventilation
ProblemPossible causes/consequences andMSolutions
The seat heating or seat
ventilation has switched
off prematurely or can-
not be switched on.The on-board voltage is too low because too many electrical consum-
ers are switched on.
XSwitch off electrical consumers that you do not need, such as the
rear window defroster or interior lighting.
Once the battery is sufficiently charged, the seat heating or seat
ventilation can be switched back on manually.
AIRSCARF
Switching on/off
GWARNING
When AIRSCARF is switched on, very hot air
can flow from the vents in the head restraints. This could result in burns in the immediate
vicinity of the air vents. There is a risk of injury.
Reduce the heater output before it becomes
too hot.
The AIRSCARF function warms the head and
neck area of vehicle occupants with warm air.
The warm air flows out of the holes in the head
restraints.
The three red indicator lamps in the button indi-
cate the heating level you have selected.
XMake sure that the SmartKey is in position 1
or 2 in the ignition lock.
XTo switch on: press button:.
Three red indicator lamps in the button light
up. The blower starts up after a preheating
phase of seven seconds.
XPress button :repeatedly until the desired
heating level is set.
XTo switch off: press button:repeatedly
until all the indicator lamps go out.
Adjust the height of the current of air blown out according to your height while adjusting the
height of the head restraint.
Make sure that there are no objects covering the
intake grille on the back of the driver's seat head
restraint.
iThe blower continues running for seven sec-
onds to cool down the heating elements.
iIf the battery voltage is too low, AIRSCARF
may switch off.
Steering wheel
Important safety notes
GWARNING
You could lose control of your vehicle if you do the following while driving:
Radjust the driver's seat, head restraint,
steering wheel or mirrors
Rfasten the seat belt
There is a risk of an accident.
Adjust the driver's seat, head restraint, steer-
ing wheel and mirror and fasten your seat belt before starting the engine.
GWARNING
Children could injure themselves if they
adjust the steering wheel. There is a risk of
injury.
100Steering wheel
Seats, steering wheel and mirrors