2018 MERCEDES-BENZ C-CLASS CABRIOLET battery

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

XTo activate:close the trunk lid.
XOpen the glove box.
XSlide the switch to position 1.
If the vehicle is unlocked centrally, the trunk
remains locked.
iYou can also lock the glove box
(Ypage 264).
XTo deactivate: open the glove box.
XSlide the switch to position 2.
If the vehicle is unlocked centrally, the trunk
will also be unlocked.
Emergency release for the trunk
You can unlock the trunk lid from the inside with
the emergency release button.
XPress emergency release button :briefly.
The trunk lid unlocks and opens.
The trunk lid can be unlocked with the trunk lid
emergency release when the vehicle is station-
ary or while driving.
The trunk lid emergency release does not unlock
the trunk lid if the battery is disconnected or
discharged. Trunk lid emergency release light:
Remergency release button
:flashes for
30 minutes after the trunk lid is opened
Remergency release button :flashes for
60 minutes after the trunk lid is closed
Side windows
Important safety notes
GWARNING
While opening the side windows, body parts
could become trapped between the side win-
dow and the door frame as the side window
moves. There is a risk of injury.
Make sure that nobody touches the side win-
dow during the opening procedure. If some-
body becomes trapped, release the switch or
pull the switch to close the side window again.
GWARNING
While closing the side windows, body parts in
the closing area could become trapped. There is a risk of injury.
When closing make sure that no parts of the
body are in the closing area. If somebody
becomes trapped, release the switch or press
the switch to open the side window again.
Side window reversing feature
The side windows are equipped with an auto-
matic reversing feature. If a solid object blocks
or restricts a side window from traveling
upwards during the automatic closing process,
the side window opens again automatically. Dur-
ing the manual closing process, the side window
only opens again automatically after the corre-
sponding switch is released. The automatic
reversing feature is only an aid and is no substi- tute for your attention when closing a side win-
dow.
Side windows85
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

Mirrors
Exterior mirrors
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
The exterior mirror on the front-passenger
side reduces the size of the image. Visible
objects are actually closer than they appear.
This means that you could misjudge the dis-
tance from road users traveling behind, e.g.
when changing lane. There is a risk of an acci-
dent.
For this reason, always make sure of the
actual distance from the road users traveling
behind by glancing over your shoulder.
Adjusting the exterior mirrors
XTurn the SmartKey to position 1or2 in the
ignition lock (Ypage 123).
XExterior mirror on the front-passenger side:
press button ;. Exterior mirror on the driver's side: press but-
ton
=.
The indicator lamp lights up in the button that
has been pressed.
The indicator lamp goes out again after some
time. You can adjust the selected exterior
mirror using button :as long as the indicator
lamp is lit.
XPress button :up, down, or to the left or
right until you have adjusted the exterior mir-
ror to the correct position. You should have a
good overview of traffic conditions.
The convex exterior mirrors provide a larger field of vision.
After the engine has been started, the exterior
mirrors are automatically heated if the rear win-
dow defroster is switched on and the outside
temperature is low.
Folding the exterior mirrors in or out
electrically
XTurn the SmartKey to position 1or2 in the
ignition lock (Ypage 123).
XBriefly press :.
Both exterior mirrors fold in or out.
iMake sure that the exterior mirrors are
always folded out fully while driving. They
could otherwise vibrate.
iIf you are driving faster than 30 mph
(47 km/h), you can no longer fold in the exte-
rior mirrors.
Resetting the exterior mirrors
If the battery has been disconnected or com-
pletely discharged, the exterior mirrors must be
reset. The exterior mirrors will otherwise not
fold in if you have activated the Automatic
Mirrors103
Seats, steering wheel and mirrors
Z

When the engine is running and the vehicle is
stationary: if you move the selector lever from a
driving position toP, the daytime running lamps
and low-beam headlamps go out after three
minutes.
When the engine is running, the vehicle is sta-
tionary and in bright ambient light: if you turn the
light switch to the Tposition, the daytime
running lamps and parking lamps switch on.
If the engine is running and you turn the light
switch to the Lposition, the manual settings
take precedence over the daytime running
lamps.
Low-beam headlamps
GWARNING
When the light switch is set to Ã, the low-
beam headlamps may not be switched on
automatically if there is fog, snow or other
causes of poor visibility due to the weather
conditions such as spray. There is a risk of an
accident.
In such situations, turn the light switch to
L.
Even if the light sensor does not detect that it is
dark, the parking lamps and low-beam head-
lamps switch on when the ignition is switched on and the light switch is set to the Lposition.
This is a particularly useful function in the event
of rain and fog.
XTo switch on the low-beam headlamps:
turn the SmartKey to position 2in the igni-
tion lock or start the engine.
XTurn the light switch to the Lposition.
The green Lindicator lamp in the instru-
ment cluster lights up.
Rear fog lamp
The rear fog lamp improves visibility of your
vehicle for the traffic behind in the event of thick
fog. You must observe the legal requirements
for the country in which you are currently driving
when operating the rear fog lamp.
XTo switch on the rear fog lamp: turn the
SmartKey in the ignition lock to position 2or
start the engine.
XTurn the light switch to the LorÃ
position.
XPress the Rbutton.
The yellow Rindicator lamp on the instru-
ment cluster lights up.
Parking lamps
!If the battery charge is very low, the parking
lamps or standing lamps are automatically
switched off to enable the next engine start.
Always park your vehicle safely and in a well lit
area, in accordance with the relevant legal
stipulations. Avoid using the Tparking
lamps over a period of several hours. If pos-
sible, switch on the right-hand Xor left-
hand W standing lamps.
XTo switch on the parking lamps: turn the
light switch to the Tposition.
The green Tindicator lamp on the instru-
ment cluster lights up.
Standing lamps
Switching on the standing lamps ensures the
corresponding side of the vehicle is illuminated.
XTo switch on the standing lamps: turn the
Smart Key to position uin the ignition lock or
remove the SmartKey.
XTurn the light switch to the W(left-hand
side of the vehicle) or X(right-hand side of
the vehicle) position.
Combination switch
:High-beam headlamps
;Turn signal, right
108Exterior lighting
Lights and windshield wipers