2018 MERCEDES-BENZ C-CLASS SEDAN key

ProblemPossible causes/consequences andMSolutions
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 85).
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 324).
or
XJump-start the vehicle (Ypage 325).
or
XConsult a qualified specialist workshop.
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 81) and replace it if necessary
(Ypage 81).
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.
SmartKey83
Opening and closing
Z

Doors
Important safet ynotes
GWARNING
If children are lef tunsupervised in th evehicle,
they could:
Rope nth edoors ,thus endangerin gother
people or road users.
Rget out and disrup ttraffic .
Roperat eth evehicle' sequipment.
Additionally, children could set th evehicle in
motion if, fo rexample, they:
Rrelease th eparking brake .
Rshiftingth eautomatic transmissio nout of
par kposition P
RStart theengine.
There is aris kof an acciden tand injury.
Whe nleavin gth evehicle, always take th e
SmartKey wit hyou and loc kth evehicle. Never
leav echildren or animals unattended in th e
vehicle. Always keep th eSmartKey out of
reach of children .
Unlockingan dopening doors from
th einside
You can ope n adoo rfrom insid eth evehicle
eve nif it has bee nlocked. You can only ope nth e
rea rdoors from insid eth evehicle if they are no t
secure dby th echild-proof locks (
Ypage 65). If
th evehicle has bee nlocke dwit hth eSmartKey
or wit hKEYLESS-GO ,opening adoo rfrom th e
insid ewill trigger th eanti-thef talar msystem.
Switc hof fth ealar m (
Ypage 76) .
XTo unlock an dope n afront door: pull door
handle ;.
If th edoo ris locked, locking knob :pop sup.
The doo ris unlocke dand opens .
XTo unlock arear door: pull reardoo rhandle.
The locking knob on th erea rdoo rpop sup and
th erea rdoo runlocks .
XTo open arear door: pull reardoo rhandle
again .
The rea rdoo ropens .
Centrally locking an dunlocking th e
vehicle from th einside
You can centrall yloc kand unloc kth evehicle
from th einside. The switches are on th edriver’s
door.
XTo unlock :press butto n:.
XTo lock :press butto n;.
Whe nth efront-passenger doo ris closed, th e
vehicle is locked.
Meanwhile, th efue lfiller flap will no tbe locke d
or unlocked.
You canno tunloc kth evehicle centrall yfrom th e
insid eif th evehicle has bee nlocke dwit hth e
SmartKey or KEYLESS-GO .
The doors can be opene dfrom th einside. You
can only ope nth erea rdoors from insid eth e
vehicle if they are no tsecure dby th echild-proof
locks (
Ypage 65).
If th evehicle has bee nlocke dwit hth eSmartKey
or wit hKEYLESS-GO ,opening adoo rfrom th e
insid ewill trigger th eanti-thef talar msystem.
Switc hof fth ealar m (
Ypage 76).
84Doors
Opening and closing

If a locked door is opened from the inside, the
previous unlock status of the vehicle will be
taken into consideration if:
Rthe vehicle was locked using the locking but-
ton for the central locking, or
Rthe vehicle was locked automatically
The vehicle will be fully unlocked if it had previ-
ously been fully unlocked. If only the driver's
door had been previously unlocked, only the
door which has been opened from the inside is
unlocked.
Automatic locking feature
XTo deactivate: press and hold button :for
approximately five seconds until a tone
sounds.
XTo activate: press and hold button ;for
approximately five seconds until a tone
sounds.
If you press one of the two buttons and do not
hear a tone, the relevant setting has already
been selected.
The vehicle is locked automatically when the
ignition is switched on and the wheels are turn-
ing.
You could therefore be locked out if:
Rthe vehicle is being pushed
Rthe vehicle is being towed
Rthe vehicle is being tested on a dynamometer.
You can activate and deactivate the automatic
locking mechanism via the multimedia system
(see the Digital Operator's Manual).
Locking/unlocking the driver's door
with the mechanical key
i
If you want to centrally lock the vehicle using
the mechanical key, begin by pressing the
locking button for the interior locking mech-
anism while the driver's door is open. Then
lock the driver's door using the mechanical
key.
XInsert the mechanical key into opening :in
the protective cap.
XPull and hold the door handle.
XPull the protective cap on the mechanical key
as straight as possible away from the vehicle
until it releases.
XRelease the door handle.
XTo lock: turn the mechanical key clockwise as
far as it will go to position 1.
XTo unlock:turn the mechanical key counter-
clockwise as far as it will go to position 1.
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 76).
Doors85
Opening and closing
Z

Trunk
Important safety notes
GWARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Exhaust
gases can enter the vehicle interior if the
trunk lid is open when the engine is running,
especially if the vehicle is in motion. There is a
risk of poisoning.
Always switch off the engine before opening
the trunk lid. Never drive with the trunk lid
open.
GWARNING
If objects, luggage or loads are not secured or
not secured sufficiently, they could slip, tip
over or be flung around and thereby hit vehicle
occupants. There is a risk of injury, particu-
larly in the event of sudden braking or a sud-
den change in direction.
Always store objects so that they cannot be
flung around. Secure objects, luggage or
loads against slipping or tipping before the
journey.
!The trunk lid swings upwards when opened.
Therefore, make sure that there is sufficient
clearance above the trunk lid.
The opening dimensions of the trunk lid can be
found in the "Vehicle data" section
(
Ypage 367).
You can limit the opening angle of the trunk lid in
the multimedia system; see the Digital Opera-
tor's Manual.
Do not leave the SmartKey in the trunk. You
could otherwise lock yourself out.
You should preferably place luggage or loads in
the trunk. Observe the loading guidelines
(
Ypage 280).
Object detection with trunk lid revers-
ing feature
Vehicles with trunk lid remote closing fea-
ture:
The trunk lid is equipped with automatic object
detection with a reversing feature. If a solid object blocks or restricts the trunk lid when
automatically opening, this procedure is stop-
ped. If a solid object blocks or restricts the trunk
lid when automatically closing, the trunk lid
opens again automatically. Automatic object
detection with reversing function is only an aid.
It is not a substitute for your attentiveness when opening and closing the trunk lid.
GWARNING
The reversing feature does not respond:
Rto soft, light and thin objects, e.g. fingers
Rover the last 1/3 in (8 mm) of the closing
movement
The reversing feature cannot prevent some-
one being trapped in these situations in par-
ticular. There is a risk of injury.
Make sure that no body parts are in close
proximity during the closing procedure.
If somebody becomes trapped:
Rpress the Fbutton on the SmartKey, or
Rpull or press the remote operating switch
on the driver's door or
Rpress the closing or locking button on the
trunk lid, or
Rpull on the trunk lid handle
Vehicles with HANDS-FREE ACCESS:
It is also possible to stop the closing process by
performing a kicking movement under the rear
bumper.
Opening and closing manually
Opening
86Trunk
Opening and closing

XPress theFbutton on the SmartKey.
or
XPull handle :.
The trunk lid opens.
Closing
XPull the trunk lid down using recess :and
push it closed.
XLock the vehicle if necessary with the &
button on the SmartKey or with KEYLESS-GO
(
Ypage 79).
Opening/closing automatically from
outside
Important safety notes
GWARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Exhaust
gases can enter the vehicle interior if the
trunk lid is open when the engine is running,
especially if the vehicle is in motion. There is a
risk of poisoning.
Always switch off the engine before opening
the trunk lid. Never drive with the trunk lid
open.
GWARNING
Parts of the body could become trapped dur-
ing automatic closing of the trunk lid. More-
over, people, e.g. children, may be standing in the closing area or may enter the closing area
during the closing process. There is a risk of
injury.
Make sure that nobody is in the vicinity of the
closing area during the closing process.
Use one of the following options to stop the
closing process:
Rpress the Fbutton on the SmartKey.
Rpull or press the remote operating switch
on the driver's door.
Rpress the closing or locking button on the
trunk lid.
Rpull the trunk lid handle
Vehicles with HANDS-FREE ACCESS:
It is also possible to stop the closing process by
performing a kicking movement under the rear
bumper.
!The trunk lid swings upwards when opened.
Therefore, make sure that there is sufficient
clearance above the trunk lid.
The opening dimensions of the trunk lid can be
found in the "Vehicle data" section
(
Ypage 367).
Opening automatically
You can open the trunk lid automatically using
the SmartKey or the handle in the trunk lid.
XPress and hold the Fbutton on the Smart-
Key until the trunk lid opens.
or
XIf the trunk lid is unlocked, pull the trunk lid
handle and let it go again immediately.
Closing automatically
:Closing button
;Locking button
XPress closing button :in the trunk lid.
Trunk87
Opening and closing
Z

Vehicles with trunk lid remote closing fea-
ture and KEYLESS-GO:when the driver's door
is closed you can simultaneously close the trunk
lid and lock the vehicle. To do this, the SmartKey
must be in the KEYLESS-GO detection range to
the rear of the vehicle.
XPress locking button ;in the trunk lid.
If KEYLESS-GO detects a SmartKey outside
the vehicle, the trunk lid closes. The vehicle is
locked.
If KEYLESS-GO detects a SmartKey in the trunk,
the trunk lid opens again after it is closed.
If KEYLESS-GO detects a second SmartKey out- side the vehicle, the trunk lid remains closed.
If KEYLESS-GO detects a SmartKey in the trunk
before the closing procedure starts, the trunk lid
remains open.
HANDS-FREE ACCESS
General notes
With KEYLESS-GO and HANDS-FREE ACCESS,
you can open or close the trunk lid or stop the
procedure without using your hands. This is use- ful if you have your hands full. To do this, make
a kicking movement under the bumper with your
foot.
Observe the following points:
RCarry your KEYLESS-GO key about your per-
son. The SmartKey must be at the rear of the
vehicle in the detection range of KEYLESS-
GO.
RWhen making the kicking movement, make
sure that you are standing firmly on the
ground and that there is sufficient clearance
to the rear of the vehicle. You could otherwise
lose your balance, for example on ice.
RAlways ensure that you only make the kicking
movement within the detection range of sen-
sors :.
RStand at least 12 in (30 cm) away from the
rear area while doing so.
RDo not come into contact with the bumper
while making the kicking movement. Other-
wise, the sensors may not function correctly.
RHANDS-FREE ACCESS does not function dur-
ing engine start.
RDirt caused by road salt or snow around sen-
sors:may restrict functionality.
Using the HANDS-FREE ACCESS with a pros-
thetic leg may restrict functionality.
RIf a KEYLESS-GO key is at the rear of the vehi-
cle in the detection range of KEYLESS-GO,
HANDS-FREE ACCESS could be triggered.
The trunk lid could thus be opened or closed
unintentionally, for example, if you:
-sit on the edge of the trunk.
-set something down or lift something up
behind the vehicle.
-polish the rear of the vehicle.
Do not carry the KEYLESS-GO key about your
person in these situations or in situations sim-
ilar to these. This will prevent unintentional
opening or closing of the trunk lid.
Important safety notes
GWARNING
The vehicle exhaust system can become very
hot. If you use HANDS-FREE ACCESS, you
could burn yourself by touching the exhaust
system. There is a risk of injury. Always
ensure that you make the kicking movement
only within the detection range of the sensors.
!If the SmartKey is within the rear detection
range of KEYLESS-GO, the following situa-
tions, for example, could lead to the uninten-
tional opening of the trunk lid:
Rwhen using an automatic car wash
Rwhen using a power washer
Make sure that the SmartKey is at least 10 ft
(3 m) away from the vehicle.
88Trunk
Opening and closing

Operation
XTo open or close:kick with your foot into
sensor detection range :beneath the
bumper.
A warning tone will sound while the trunk lid is
opening or closing.
XIf the trunk lid does not open or close after
several attempts: wait at least ten seconds
then move your leg under the bumper once
again.
If you hold your foot under the bumper for too
long, the trunk lid does not open or close.
Repeat the leg movement more quickly if this
occurs.
To stop the opening or closing procedure, you
have the following options:
RKick with your foot into sensor detection
range :beneath the bumper.
RPress the closing button on the trunk lid.
RPull the handle on the outside of the trunk lid.
RPress the Fbutton on the SmartKey.
If the trunk lid closing procedure has been stop-
ped:
RMove your foot under the bumper again and
the trunk lid will open.
If the trunk lid opening procedure has been
stopped:
RMove your foot under the bumper again and
the trunk lid will close.
Opening/closing automatically from
inside
Important safety notes
GWARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Exhaust
gases can enter the vehicle interior if the
trunk lid is open when the engine is running,
especially if the vehicle is in motion. There is a
risk of poisoning.
Always switch off the engine before opening
the trunk lid. Never drive with the trunk lid
open.
GWARNING
Parts of the body could become trapped dur-
ing automatic closing of the trunk lid. In addi-
tion, people may be standing in the closing
area or may enter the closing area, e.g. chil-
dren, during the closing procedure. There is a
risk of injury.
Make sure that nobody is in the vicinity of the
closing area during the closing process.
Release the remote operating switch imme-
diately if somebody becomes trapped. To re-
open the trunk lid, pull on the remote operat-
ing switch.
Vehicles with HANDS-FREE ACCESS:
It is also possible to stop the closing process by
performing a kicking movement under the rear
bumper.
!The trunk lid swings upwards when opened.
Therefore, make sure that there is sufficient
clearance above the trunk lid.
The opening dimensions of the trunk lid can be
found in the "Vehicle data" section
(
Ypage 367).
Trunk89
Opening and closing
Z

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.
GWARNING
If children operate the side windows they
could become trapped, particularly if they are left unsupervised. There is a risk of injury.
Activate the override feature for the rear side
windows. When leaving the vehicle, always
take the SmartKey with you and lock the vehi-
cle. Never leave children unsupervised in the
vehicle.
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 windowonly 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.
GWARNING
The reversing feature does not react:
Rto soft, light and thin objects, e.g. small fin-
gers
Rwhile resetting
This means that the reversing feature cannot
prevent someone being trapped in these sit-
uations. There is a risk of injury.
Make sure that no body parts are in close
proximity during the closing procedure. If
someone becomes trapped, press the switch
to open the side window again.
Opening and closing the side win-
dows
The switches for all side windows are located on
the driver's door. There is also a switch on each
door for the corresponding side window.
The switches on the driver's door take prece-
dence.
:Front left
;Front right
=Rear right
?Rear left
XTurn the SmartKey to position 1or2 in the
ignition lock.
XTo open manually: press and hold the cor-
responding switch.
XTo open fully: press the switch beyond the
pressure point and release it.
Automatic operation is started.
XTo close manually: pull the corresponding
switch and hold it.
XTo close fully: pull the switch beyond the
pressure point and release it.
Automatic operation is started.
XTo interrupt automatic operation: press/
pull the corresponding switch again.
If you press the switch beyond the pressure
point and release, automatic operation is star-
ted in the corresponding direction. You can stop
automatic operation by pressing/pulling the
switch again.
You can continue to operate the side windows
after you switch off the engine or remove the
SmartKey. This function remains active for five
minutes or until you open a front door.
When the override feature for the side windows
is activated, the side windows cannot be oper-
ated from the rear (
Ypage 65).
Side windows91
Opening and closing
Z