2016 MERCEDES-BENZ C-Class SEDAN change key battery

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 evehicle.
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
on your own .
XTo change th esetting: press and hold down
th e% and& buttons simultaneousl y
for approximately six seconds until th ebat -
tery chec klamp flashes twice (
Ypage 84).
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.
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 th erear door .
XTo lock centrally: touch theouter sensor
surfac eon on eof th edoor handles .
XTo restoreth efactory settings: press and
hold th e% and& buttons sim ultane-
ousl yfor approximately six seconds until th e
battery chec klamp flashes twice
(
Ypage 84) .
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 79) .
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 :
RUnlocking thedriver's door (Ypage 89)
RLocking th evehicl e (Ypage 89 )
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 .
SmartKey83
Opening and closing
Z

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
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 84).
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 83).
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 :.
84SmartKey
Opening and closing

ProblemPossible causes/consequences andMSolutions
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 350).
or
XJump-start the vehicle (Ypage 352).
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 84) and replace it if necessary
(Ypage 84).
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.
Doors87
Opening and closing
Z

Control panel in the grab handle (rear
compartment)
:Reading lamp
;pTo switch the reading lamp on/off
Interior lighting control
General notes
In order to prevent the vehicle's battery from
discharging, the interior lighting functions are
automatically deactivated after some time
except when the SmartKey is in position 2in the
ignition lock.
The color, brightness and display lighting for the
ambient lighting are set using the multimedia
system (see the separate operating instruc-
tions).
Automatic interior lighting control
XTo switch on/off: press the|button.
When the automatic interior lighting control is
activated, the button is flush with the over-
head control panel.
The interior lighting automatically switches on if
you:
Runlock the vehicle
Ropen a door
Rremove the SmartKey from the ignition lock
The interior light is activated for a short while
when the SmartKey is removed from the ignition
lock. This delayed switch-off can be adjusted via
the multimedia system (see the separate oper-
ating instructions).
Replacing bulbs
Important safety notes
GWARNING
Bulbs, lamps and connectors can get very hot
when operating. If you change a bulb, you
could burn yourself on these components.
There is a risk of injury.
Allow these components to cool down before
changing a bulb.
Do not use a bulb that has been dropped or if its
glass tube has been scratched.
The bulb may explode if:
Ryou touch it
Rit is hot
Ryou drop it
Ryou scratch it
Only operate bulbs in enclosed lamps designed
for that purpose. Only install spare bulbs of the same type and the specified voltage.
Marks on the glass tube reduce the service life
of the bulbs. Do not touch the glass tube with
your bare hands. If necessary, clean the glass
tube when cold with alcohol or spirit and rub it
off with a lint-free cloth.
Protect bulbs from moisture during operation.
Do not allow bulbs to come into contact with
liquids.
Only replace the bulbs listed (
Ypage 123).
Have the bulbs that you cannot replace yourself
replaced at a qualified specialist workshop.
If you require assistance replacing bulbs, con-
sult a qualified specialist workshop.
If the new bulb still does not light up, consult a
qualified specialist workshop.
Headlamps and lights are an important aspect of
vehicle safety. You must therefore make sure
that these function correctly at all times. Have
the headlamp setting checked regularly.
Veh icles wit
h LED headlamps:
the front and
rear light clusters of your vehicle are equipped
with LED light bulbs. Do not replace the bulbs
yourself. Contact a qualified specialist work-
shop which has the necessary specialist knowl-
edge and tools to carry out the work required.
122Replacing bulbs
Lights and windshield wipers

Hybrid drive system
Display messagesPossible causes/consequences andMSolutions
d
VehicleOperationalSwitchtheIgnitionOff Before Exiting
PLUG-IN HYBRID vehicles:
You are exiting the vehicle when it is in a ready-to-drive state. The
READY indicator in the multifunction display is on. A warning tone also
sounds.
If you leave the vehicle:
XSecure the vehicle against rolling away (Ypage 177).
XSwitch off the ignition and remove the SmartKey.
If you do not leave the vehicle:
XSwitch off the electrical consumers, e.g. automatic climate control,
seat heating.
Please note the following: The electrical consumers are supplied by
the 12 V battery. If the vehicle is left in a ready-to-drive state for an
extended period, it will switch off once the 12 V battery is almost
empty. It will then only be possible to start the vehicle using a second
battery (jump-starting).
Change the currentdrive programbeforechangingtheoperating mode.or
Exit manual drive
program M beforechangingtheoperat‐ing mode.
PLUG-IN HYBRID vehicles:
You have attempted to change the operating mode in the automatic
drive program S(Sport), S+(Sport Plus) or in the manual drive pro-
gram M.
XActivate drive program C(Comfort) or E(Economy) (Ypage 229).
XSelect the preferred operating mode HYBRID,E-MODE,E-SAVE or
CHARGE (Ypage 226).
E-MODE CurrentlyUnavailable
PLUG-IN HYBRID vehicles:
The condition of charge of the high-voltage battery has dropped to the
lower limit and the E-MODEoperating mode has been switched off.
Driving with the internal combustion engine is activated and the oper-
ating mode switches to the basic HYBRIDsetting.
XContinue driving using the internal combustion engine.
You can switch to the E-SAVEorCHARGE operating mode as
required (
Ypage 226).
If you select CHARGE, the high-voltage battery is charged.
Once the charge level display for the high-voltage battery has
increased slightly, you can switch to the E-MODEoperating mode
again.
272Display messages
On-board computer and displays

Display messagesPossible causes/consequences andMSolutions
Ð
Power Steering Mal‐function See Opera‐tor's Manual
The powersteering is malfunctioning .
A warning tone also sounds.
GWARNIN G
You will need to use mor eforce to steer .
There is aris kof an accident.
XChec kwhether you are able to apply th eextr aforce required.
If you ar eabl eto steer safely:
XDrive on carefully.
XVisit aqualified specialist workshop immediately.
If you ar eunable to steer safely:
XDo no tdrive on .
XConsult aqualified specialist workshop .
Phone No ServiceYour vehicleis outside th enetwork provider' stransmitter/receiver
range.
XWait until th emobile phone operational readiness symbol appear s
in th emultifunction display.
¥
Check Washer Fluid
The washer flui dlevel in th ewasher flui dreservoir has dropped belo w
th eminimum .
XAddwasher flui d (Ypage 333).
SmartKey
Display messagesPossible causes/consequences and MSolutions
Â
KeyDoesNotBelongto Vehicl e
You haveput th ewrong SmartKey in th eignition lock.
XUse th ecorrec tSmartKey.
Â
Tak eYou rKey fro mIgnition
The SmartKey is in th eignition lock.
XRemove th eSmartKey.
Â
Obtain aNew Key
The SmartKey needs to be replaced.
XVisit aqualified specialist workshop .
Â
ReplaceKey Batter y
The SmartKey battery is discharged.
XChange thebatterie s (Ypage 84) .
Display messages285
On-board computer and displays
Z