2018 MERCEDES-BENZ C-CLASS CABRIOLET key

Important safety notes
The intervention of PRE-SAFE®PLUScanno t
preven tan imminent collision .
The driver is no twarned about th eintervention
of PRE-SAF E
®PLUS.
PRE-SAF E®PLUSdoes no tinterven eif th evehi-
cle is backin gup.
When driving ,or when parking or exiting apark -
ing spac ewit hassistanc efrom Parking Pilot ,
PRE-SAF E
®PLUSwill no tapply th ebrakes.
Function
PRE-SAF E®PLUSintervenes in certain situa-
tion sif th eradar sensor system detects an
imminent head-on or rear-end collision .
PRE-SAF E
®PLUStakes th efollowin gmeasures
depending on th ehazardous situation detected:
Rif th eradar sensor system detects that a
head-on collision is imminent ,th eseat belt s
are pre-tensioned.
Rif th eradar sensor system detects that arear -
en dcollision is imminent :
-thebrak epressur eis increased if th edriver
applie sth ebrakes when th evehicl eis sta-
tionary.
-th eseat belt sare pre-tensioned.
The PRE-SAF E®PLUSbraking application is can -
celed:
Rif th eaccelerato rpedal is depressed when a
gear is engage d
Rif theris kof acollision passes or is no longer
detecte d
Rif Distanc ePilot DISTRONI Cindicates an
intention to pull away
If th ehazardous situation passes without result -
ing in an accident, th eoriginal setting sare
restored .
Automatic measures after an acci-
dent
Immediately after an accident, th efollowin g
measures are implemented, depending on th e
typ eand severit yof th eimpact :
Rthehazard warning lamp sare switched on
Rth eemergenc ylighting is activated
Rth evehicl edoor sare unlocked
Rth efron tside windows are lowered
Rvehicles wit h amemory function :th eelectri-
call yadjustable steering whee lis raised when
th edriver' sdoor is opened
Rth eengin eis switched off and th efuel suppl y
is cut off
Rvehicles wit hmbrace :automatic emergenc y
call
Children in the vehicle
Important safety notes
Acciden tstatistics sho wthat children secured
in th erear seat sare safer than children secured
in th efront-passenger seat .Fo rthis reason ,
Mercedes-Ben zstrongly advises that you instal l
a child restrain tsystem on arear seat .Children
are generally bette rprotected there .
If achild younger than twelve years old and
under 5ft (1.50 m) in height is traveling in th e
vehicle:
Ralways secure th echild in achild restrain t
system suitable for Mercedes-Ben zvehicles.
The child restrain tsystem must be appropri-
ate to th eage, weigh tand siz eof th echild
Rbe sur eto observ eth einstruction sand safet y
note sin this section in addition to th echild
restrain tsystem manufacturer' sinstallation
instruction s
Rbe sureto observ eth einstruction sand safet y
note son th e"Occupant classification system
(OCS)" (
Ypage 51)
GWARNIN G
If you leav echildren unsupervised in th evehi-
cle ,they could set it in motion by, for example:
Rrelease th eparking brake.
Rshif tth eautomatic transmission out of th e
parking position P.
Rstart theengine.
In addition ,they may operate vehicl eequip-
men tand become trapped .Ther eis aris kof
an acciden tand injury.
When leaving th evehicle, always tak eth e
SmartKey wit hyou and loc kth evehicle. Never
leav echildren unsupervised in th evehicle.
Children in the vehicle59
Safety
Z

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

XTo arm:lock the vehicle with the SmartKey or
KEYLESS-GO.
Indicator lamp :flashes. The alarm system
is armed after approximately ten seconds.
XTo disarm: unlock the vehicle with the Smart-
Key or KEYLESS-GO.
or
XInsert the SmartKey into the ignition lock.
or
XVehicles with KEYLESS-GO start function
or KEYLESS-GO: press the Start/Stop but-
ton.
The SmartKey must be in the vehicle.
A visual and audible alarm is triggered if the
alarm system is armed and you open:
Ra door
Rthe vehicle with the mechanical key
Rthe trunk lid
Rthe hood
Rthe stowage compartment/telephone com-
partment under the armrest in vehicles with
automatic transmission
XTo stop the alarm with the SmartKey:
press the %or& button on the Smart-
Key.
The alarm is stopped.
or
XVehicles with KEYLESS-GO start-function
or KEYLESS-GO: remove the Start/Stop but-
ton from the ignition lock (
Ypage 124).
XInsert the SmartKey into the ignition lock.
The alarm is stopped.
XTo stop the alarm using KEYLESS-GO:
grasp the outside door handle. The SmartKey
must be outside the vehicle.
The alarm is stopped.
or
XPress the Start/Stop button on the dash-
board. The SmartKey must be inside the vehi-
cle.
The alarm is stopped.
The alarm is not switched off, even if you close
the op en d
oor that triggered it, for example.
iIf the alarm continues for more than
30 seconds, the mbrace emergency call sys-
tem automatically notifies the Customer
Assistance Center. This is done either by text
message or data connection. The emergency call system sends a message
or establishes a data connection provided
that:
Ryou have subscribed to the mbrace service.
Rthe mbrace service has been activated
properly.
Rthe necessary mobile phone network is
available.
Protection against theft75
Safety
Z

SmartKey
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.
GWARNING
If you attach heavy or large objects to the
SmartKey, the SmartKey could be uninten-
tionally turned in the ignition lock. This could
cause the engine to be switched off. There is a risk of an accident.
Do not attach any heavy or large objects to the
SmartKey. Remove any bulky key rings before
inserting the SmartKey into the ignition lock.
!Keep the SmartKey away from strong mag-
netic fields. Otherwise, the remote control
function could be affected.
Strong magnetic fields can occur in the vicin-
ity of powerful electrical installations.
Do not keep the SmartKey:
Rwith electronic devices, e.g. a mobile phone
or another SmartKey.
Rwith metallic objects, e.g. coins or metal foil.
Rinside metallic objects, e.g. a metal case.
This can affect the functionality of the Smart- Key. Vehicles with KEYLESS-GO start function:
do
not keep the SmartKey in the cargo compart-
ment. Otherwise, the SmartKey may not be
detected, e.g. when starting the engine using
the Start/Stop button.
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
SmartKey functions
:& Locks the vehicle
;FOpens the trunk lid
=%Unlocks the vehicle
XTo unlock centrally: press the%button.
If you do not open the vehicle within approx-
imately 40 seconds of unlocking:
Rthe vehicle is locked again.
Rprotection against theft is reactivated.
XTo lock centrally: press the&button.
The SmartKey centrally locks and unlocks the
following components:
Rthe doors
Rthe trunk lid
Rthe glove box
Rthe fuel filler flap
The turn signals flash once when unlocking and
three times when locking.
You can also set an audible signal to confirm
that the vehicle has been locked. The audible
signal can be activated and deactivated via the
76SmartKey
Opening and closing

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