2018 MERCEDES-BENZ C CLASS key battery

Engaging park position automati-
cally ............................................... 147
Engaging reverse gear ................... 147
Engaging the park position ............ 146
Gearshift recommendation ............ 154
Gliding mode ................................. 149
Kickdown ....................................... 149
Manual shifting .............................. 152
Oil temperature (on-board com-
puter, Mercedes-AMG vehicles) ..... 226
Overview ........................................ 146
Permanent setting ......................... 152
Problem (malfunction) ................... 155
Pulling away ................................... 139
Starting the engine ........................ 138
Steering wheel paddle shifters ...... 152
Transmission position display
(DIRECT SELECT lever) ................... 148
Transmission positions .................. 148
Automatic transmission emer-
gency mode ....................................... 155
B
Back button ....................................... 271
Backup lamp
Display message ............................ 242
Replacing bulbs ............................. 119
Bag hook ............................................ 285
BAS (Brake Assist System) ................. 66
Basic settings
see Settings
Battery (SmartKey)
Checking .......................................... 81
Important safety notes .................... 80
Replacing ......................................... 81
Battery (vehicle)
Charging ........................................ 324
Display message ............................ 244
Important safety notes .................. 322
Jump starting ................................. 325
Belt
see Seat belts
Belt warning ......................................... 49
Blind Spot Assist
Activating/deactivating (on-
board computer) ............................ 223
Display message ............................ 248 Notes/function .............................. 200
see Active Blind Spot Assist
Blower
see Climate control
BlueTEC
see DEF
Bluetooth
®
Connecting a different mobile
phone ............................................ 278
Searching for a mobile phone ........ 278
see also Digital Operator's Man-
ual .................................................. 270
Telephony ...................................... 277
Box (trunk) ......................................... 286
Brake
Active Brake Assist with cross-
traffic function ................................. 73
Brake Assist
see BAS (Brake Assist System)
Brake assistance
see BAS (Brake Assist System)
Brake fluid
Display message ............................ 236
Notes ............................................. 365
Brake force distribution
see EBD (electronic brake force
distribution)
Brake linings
Display message ............................ 236
Brakes
ABS .................................................. 66
Adaptive Brake Assist ...................... 68
BAS .................................................. 66
Brake fluid (notes) ......................... 365
Display message ............................ 231
EBD .................................................. 72
High-performance brake system .... 168
Hill start assist ............................... 140
HOLD function ............................... 179
Important safety notes .................. 166
Maintenance .................................. 167
Parking brake ................................ 162
Riding tips ...................................... 166
Warning la mp ................................. 260
Bre

akdown
Where will I find...? ........................ 316
see Flat tire
see Towing away
6Index

Adjusting the 4-way lumbar sup-
port ................................................ 104
Adjusting the head restraint .......... 102
Calling up a stored setting (mem-
ory function) .................................. 111
Cleaning the cover ......................... 314
Folding the backrest (rear com-
partment) forwards/back .............. 283
Important safety notes .................. 100
Seat heating .................................. 104
Seat heating problem .................... 105
Seat ventilation .............................. 105
Seat ventilation problem ................ 105
Storing settings (memory func-
tion) ............................................... 111
Securing a load
see Securing cargo
Securing cargo .................................. 285
Selecting a gear
see Automatic transmission
Selector lever
Cleaning ......................................... 314
see Automatic transmission
Sensors (cleaning instructions) ....... 312
Service center
see Qualified specialist workshop
Service Center
see Qualified specialist workshop
Service menu (on-board com-
puter) .................................................. 221
Service message
see ASSYST PLUS
Service products
Brake fluid ..................................... 365
Coolant (engine) ............................ 365
DEF special additives ..................... 364
Engine oil ....................................... 364
Fuel ................................................ 361
Important safety notes .................. 361
Refrigerant (air-conditioning sys-
tem) ............................................... 367
Washer fluid ................................... 366
Setting the date/time format
see also Digital Operator's Man-
ual .................................................. 270
Setting the language
see also Digital Operator's Man-
ual .................................................. 270 Setting the time
see also Digital Operator's Man-
ual .................................................. 270
Settings
Factory (on-board computer) ......... 226
On-board computer ....................... 222
SETUP (on-b oard c
omputer,
Mercedes-AMG vehicles) .................. 227
Side impact air bag ............................. 51
Side marker lamp (display mes-
sage) ................................................... 242
Side windows
Cleaning ......................................... 311
Convenience closing feature ............ 92
Convenience opening feature .......... 92
Important safety information ........... 90
Opening/closing .............................. 91
Problem (malfunction) ..................... 93
Resetting ......................................... 93
Reversing feature ............................. 91
SIRIUS services
see also Digital Operator's Man-
ual .................................................. 270
Ski and snowboard bag .................... 282
Sliding sunroof
Important safety notes .................... 94
Opening/closing .............................. 95
Problem (malfunction) ..................... 98
Resetting ......................................... 95
see Panorama roof with power
tilt/sliding panel
SmartKey
Changing the battery ....................... 81
Changing the programming ............. 80
Checking the battery ....................... 81
Convenience closing feature ............ 92
Convenience opening feature .......... 92
Display message ............................ 257
Door central locking/unlocking ....... 78
Important safety notes .................... 78
KEYLESS-GO start function .............. 80
Loss ................................................. 82
Mechanical key ................................ 80
Overview .......................................... 78
Positions (ignition lock) ................. 136
Problem (malfunction) ..................... 82
Starting the engine ........................ 138
20Index

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

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

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