2018 MERCEDES-BENZ C-CLASS SEDAN battery

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

Opening and closing
XTo open:pull remote operating switch :for
the trunk lid until the trunk lid opens.
XTo close: press and hold remote operating
switch :for the trunk lid until the trunk lid is
completely closed.
When the vehicle is stationary, you can close the
trunk lid from the driver's seat. When the vehicle
is also unlocked, you can also open the trunk lid
from inside.
Locking the trunk separately
You can lock the trunk separately. If you then
unlock the vehicle centrally, the trunk remains
locked and cannot be opened.
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 281).
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.
90Side windows
Opening and closing

Adjusting the 4-way lumbar support
:Raises thebackrest contour
;Soften sth ebackrest contour
=Lowers th ebackrest contour
?Harden sth ebackrest contour
You can adjust th econtour of th efron tseat
backrest sindividually to provid eoptimum sup-
por tfor your back.
Adjusting the AMG Perfor mance Seat
To adjust th econtour of th eseat and for
improve dlateral support ,you can individually
adjust th efron tseats.
Adjusting th esid ebolsters of th esea tcush -
ion
XTo set narrower: press button:.
XTo set wider: press button;.
To adjust th esid ebolsters of th esea tback -
res t
XTo set narrower: press button=.
XTo set wider: press button?.
Switching the seat heating on/off
Switching on/off
GWARNIN G
Repeatedly switching on th eseat heating can
caus eth eseat cushion and backrest pads to
become ver yhot .The healt hof person swit h
limite dtemperature sensitivit yor alimite d
abilit yto reac tto high temperatures may be
affecte dor they may eve nsuffer burn-like
injuries. There is aris kof injury.
Therefore ,do no tswitch th eseat heating on
repeatedly.
The three red indicator lamp sin th ebutto nindi-
cat eth eheating level you hav eselected.
The system automatically switches down from
level 3to level 2after approximately eigh t
minutes.
The system automatically switches down from
level 2to level 1after approximately te n
minutes.
The system automatically switches off approx -
imately 20 minute safter it is set to level 1.
XTurn theSmartKey to position 1or2 in th e
ignition loc k (Ypage 136).
XTo switch on: press button: repeatedly
until th edesired heating level is set .
XTo switch off:press butto n: repeatedly
until all th eindicator lamp sgo out .
iIf thebattery voltag eis to olow, th eseat
heating may switch off .
iIf drive programEis selected, th epowe rof
th eseat heating is reduced.
104Seats
Seats, steering wheel and mirrors

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 136).
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 slid-
ing sunroof using the "Convenience opening"
feature (
Ypage 92). 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.
Problems with the seat heating/seat ventilation
ProblemPossible causes/consequences and MSolutions
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.
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.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children unsupervised in the vehicle.
The electrically adjustable steering wheel can
still be adjusted when there is no key in the igni-
tion lock.
Steering wheel105
Seats, steering wheel and mirrors
Z

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 136).
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
Mirror Foldingfunction in the multimedia
system.
XTurn the SmartKey to position 1or2 in the
ignition lock (Ypage 136).
XBriefly press :.
Folding the exterior mirrors in or out
automatically
When theAutomatic Mirror Foldingfunc-
tion is activated in the multimedia system (see
Digital Operator's Manual):
Rthe exterior mirrors fold in automatically as
soon as you lock the vehicle from the outside.
Rthe exterior mirrors fold out again automati-
cally as soon as you unlock the vehicle.
iIf the exterior mirrors have been folded in
manually, they do not fold out.
Exterior mirror pushed out of position
If an exterior mirror has been pushed out of
position, proceed as follows:
XVehicles without electrically folding exte-
rior mirrors: manually move the exterior mir-
ror into the correct position.
XVehicles with electrically folding exterior
mirrors: press and hold button :until you
hear a click and then the mirror engaging in
position (
Ypage 109).
The mirror housing is engaged again and you
can adjust the exterior mirrors as usual
(
Ypage 108).
Automatic anti-glare mirrors
GWARNING
Electrolyte may escape if the glass in an auto-
matic anti-glare mirror breaks. The electrolyte
is harmful and causes irritation. It must not
come into contact with your skin, eyes, res-
piratory organs or clothing or be swallowed.
There is a risk of injury.
Mirrors109
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
114Exterior lighting
Lights and windshield wipers