2018 MERCEDES-BENZ C-CLASS SEDAN key

Children in the vehicle
Important safety notes
Accident statistics show that children secured
in the rear seats are safer than children secured
in the front-passenger seat. For this reason,
Mercedes-Benz strongly advises that you install
a child restraint system on a rear seat. Children are generally better protected there.
If a child younger than twelve years old and
under 5 ft (1.50 m) in height is traveling in the
vehicle:
Ralways secure the child in a child restraint
system suitable for Mercedes-Benz vehicles.
The child restraint system must be appropri-
ate to the age, weight and size of the child
Rbe sure to observe the instructions and safety
notes in this section in addition to the child
restraint system manufacturer's installation
instructions
Rbe sure to observe the instructions and safetynotes on the "Occupant classification system
(OCS)" (
Ypage 52)
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.
GWARNING
If persons, particularly children are subjected to prolonged exposure to extreme heat or
cold, there is a risk of injury, possibly even
fatal. Never leave children unattended in the
vehicle.
GWARNING
If the child restraint system is subjected to
direct sunlight, parts may get very hot. Chil-
dren may burn themselves on these parts,
particularly on the metal parts of the child
restraint system. There is a risk of injury.
If you leave the vehicle, taking the child with
you, always ensure that the child restraint
system is not exposed to direct sunlight. Pro- tect it with a blanket, for example. If the child
restraint system has been exposed to direct
sunlight, let it cool down before securing the
child in it. Never leave children unattended in
the vehicle.
Always ensure that all vehicle occupants have
their seat belts fastened correctly and are sitting
properly. Particular attention must be paid to
children.
Observe the safety notes on the seat belt
(
Ypage 46 )and the notes on correct use of seat
belts (Ypage 47).
A booster seat may be necessary to achieve
proper seat belt positioning for children over
41 lb s(18 kg) until they reach a height where a
three-point seat belt can be properly fastened
without a booster seat.
Special seatbelt retractor
GWARNING
If the seat belt is released while driving, the
child restraint system will no longer be
secured properly. The special seat belt retrac- tor is disabled and the inertia real draws in a
portion of the seat belt. The seat belt cannot
be immediately refastened. There is an
increased risk of injury, possibly even fatal.
Stop the vehicle immediately, paying atten-
tion to road and traffic conditions. Reactivate
the special seat belt retractor and secure the
child restraint system properly.
All seat belts in the vehicle, except the driver's
seat belt, are equipped with a special seat belt
retractor. When activated, the special seat belt
retractor ensures that the seat belt cannot
slacken once the child seat is secured.
60Children in the vehicle
Safety

Always observe the child restraint system man-
ufacturer's installation and operating instruc-
tions.
Forward-facing child restraint system
If it is absolutely necessary to install a forward-
facing child restraint system on the front-
passenger seat, always move the front-
passenger seat as far back as possible. Fully
retract the seat cushion length. The entire base
of the child restraint system must always rest on
the seat cushion of the front-passenger seat.
The backrest of the child restraint system must
lie as flat as possible against the backrest of thefront-passenger seat. The child restraint system
must not touch the roof or be subjected to a load
by the head restraint. Adjust the angle of the
seat backrest and the head restraint position
accordingly. Always make sure that the shoul-
der belt strap is correctly routed from the vehi-
cle belt outlet to the shoulder belt guide on the
child restraint system. The shoulder belt strap
must be routed forward and down from the vehi-
cle belt outlet. If necessary, adjust the vehicle
belt outlet and the front-passenger seat accord-
ingly.
Always observe the child restraint system man-
ufacturer's installation and operating instruc-
tions.
Child-proof locks
Important safety notes
GWARNING
If children are traveling in the vehicle, they
could:
Ropen doors, thus endangering other people
or road users
Rexit the vehicle and be caught by oncoming
traffic
Roperate vehicle equipment and become
trapped
There is a risk of an accident and injury.
Always activate the child-proof locks and
override feature if children are traveling in the vehicle. When leaving the vehicle, always take
the key with you and lock the vehicle. Never
leave children unattended in the vehicle. Override feature for:
Rthe rear doors (Ypage 65)
Rthe rear side windows (Ypage 65)
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.
GWARNING
If persons, particularly children are subjected to prolonged exposure to extreme heat or
cold, there is a risk of injury, possibly even
fatal. Never leave children unattended in the
vehicle.
GWARNING
If the child restraint system is subjected to
direct sunlight, parts may get very hot. Chil-
dren may burn themselves on these parts,
particularly on the metal parts of the child
restraint system. There is a risk of injury.
If you leave the vehicle, taking the child with
you, always ensure that the child restraint
system is not exposed to direct sunlight. Pro- tect it with a blanket, for example. If the child
restraint system has been exposed to direct
sunlight, let it cool down before securing the
child in it. Never leave children unattended in
the vehicle.
64Children in the vehicle
Safety

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)
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
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 137).
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 open door 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.
76Protection against theft
Safety

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 on the parcel shelf or in
the trunk. 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 using HANDS-FREE ACCESS
Rwhen the external door handles are touched
Rduring convenience closing
SmartKey functions
:& Locks the vehicle
;FOpens/closes 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 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
78SmartKey
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.
XTo open the trunk lid automatically from
outside the vehicle: if the SmartKey is loca-
ted in the immediate vicinity of the vehicle,
press the Fbutton on the SmartKey.
When the trunk lid closes you can then
release the button.
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 138).
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 using HANDS-FREE ACCESS
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.
Further information on the convenience clos-
ing feature (
Ypage 92).
XTo unlock the trunk lid: pull the handle on
the trunk lid.
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 81) 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.
SmartKey79
Opening and closing
Z

KEYLESS-GOstart function
Gene ral notes
Bear in min dthat th eengin ecan be started by
any of th evehicl eoccupant sif there is aSmart -
Key in th evehicl e (
Ypage 138).
Changing the settings ofthe locking
system
You can chang eth esetting sof th elocking sys-
tem. This mean sthat only th edriver's door and
th efuel filler flap are unlocke dwhen th evehicl e
is unlocked. This is useful if you frequentl ytravel
alone.
XTo change th esetting: press and hold down
th e% and& buttons simultaneousl y
for approximately six seconds until th ebat -
tery chec klamp (
Ypage 81) flashes twice .
If th esetting of th elocking system is changed
within th esignal range of th evehicle, pressing
th e& or% button:
Rlocks or
Runlocks th evehicl e
The SmartKey no wfunction sas follows :
XTo unlock: press the% buttononce .
XTo unlock centrally: press the% button
twice .
XTo lock: press the& button.
XTo restor eth efactory settings: press and
hold th e% and& buttons simultane -
ousl yfor approximately six seconds until th e
battery chec klamp (
Ypage 81) flashes
twice .
The KEYLESS-GO function scan be changed as
follows :
XTo unlock th edriver's door :touch th einner
surfac eof th edoor handle on th edriver's
door .
XTo unlock centrally: touch theinner surfac e
of th edoor handle on th efront-passenger
door or there
ar door .
XTo lock centrally: touch theouter sensor
surfac eon on eof th edoor handles .
Mechanical key
Gene ral notes
If th evehicl ecan no longer be locke dor
unlocke dwit hth eSmartKey or KEYLESS-GO ,
use th emechanical key.
If you use th emechanical ke yto unloc kand
open th edriver's door ,th eanti-thef talarm sys-
te m will be triggered .Switc hoff th ealarm
(
Ypage 76) .
If you unloc kth evehicl eusin gth emechanical
key, th efuel filler flap will no tbe unlocke dauto -
matically.
XTo unlock th efuel filler flap: insert the
SmartKey int oth eignition lock.
Removing the mechanical key
XPush release catch :in th edirection of th e
arrow and at th esam etime remove mechan -
ical ke y; from th eSmartKey.
Further information on locking/unlocking th e
driver's door (
Ypage 85).
Inserting the mechanical key
XPush mechanical ke y; completely int oth e
SmartKey until it engage sand release
catch :is bac kin it sbasic position .
SmartKey battery
Import ant safety notes
GWARNIN G
Batterie scontain toxic and corrosiv esubstan -
ces. If batterie sare swallowed, it can result in
80SmartKey
Opening and closing

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
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 81).
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 80).
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 :.
SmartKey81
Opening and closing
Z

XRepeatedly tap theSmartKey against your
palm until battery =falls out .
XInsertth ene wbattery wit hth epositive ter-
minal facing upwards. Use alint-free cloth to
do so.
XMak esur ethat th esurfac eof th ebattery is
free of lint, grease and other contaminants.
XInser tth efron ttab sof battery compartmen t
cover :intoth ehousing first and then press
to close it .
XInsertmechanical ke y; intoth eSmartKey
(Ypage 80).
XChec kth efunction of all SmartKey buttons on
th evehicle.
Problems with the SmartKey
ProblemPossible causes/consequences and MSolutions
You can no longer lockor
unlock th evehicl eusin g
th eSmartKey.The SmartKey battery is discharged or nearly discharged.
XChec kth eSmartKey battery (Ypage 81) and replace it if necessar y
(Ypage 81).
If this does no twork:
XLoc kor unlock th evehicl eusin gth emechanical ke y (Ypage 85).
There is interferenc efrom apowerful source of radi owaves.
XLoc kor unlock th evehicl eusin gth emechanical ke y (Ypage 85).
The SmartKey is faulty.
XLockor unlock th evehicl eusin gth emechanical ke y (Ypage 85).
XHaveth eSmartKey checke dat aqualified specialist workshop.
You can no longer loc kor
unlock th evehicl eusin g
KEYLESS-GO .KEYLESS-GO was deactivated.
XReactivateKEYLESS-GO (Ypage 79).
The SmartKey battery is discharged or nearly discharged.
XCheckth eSmartKey battery (Ypage 81) and replace it if necessar y
(Ypage 81).
If this does no twork:
XLoc kor unlock th evehicl eusin gth emechanical ke y (Ypage 85).
There is interferenc efrom apowerful source of radi owaves.
XLoc kor unlock th evehicl eusin gth emechanical ke y (Ypage 85).
82SmartKey
Opening and closing