2021 MERCEDES-BENZ C-CLASS COUPE battery

Coupling up/uncoupling a trailer
&
WARNING Risk of inju ryfrom theve hicle
le ve l being changed
Ve hicles with le vel control sy stem: the
ve hicle le vel may be changed unin tentional ly,
e.g. by ot her persons. You may become trap‐
ped if you couple up or uncouple a trailer
while theve hicle le vel is changing. In addi‐
tion, other people could become trapped if
th eir limbs are between theve hicle body and
th e tyres or underneath theve hicle.
When coupling up or uncoupling a trailer,
make sure that: #
The doors or tailgate are not opened or
closed. #
You do not initiate the le vel control sys‐
te m and do not operate theDY NA MIC
SELECT switch. #
Do not lock or unlock theve hicle. Re
quirements:
R The ball neck is extended and engaged in a
secu rely loc ked position. Tr
ailers with a 7-pin plug can be connec tedto
th eve hicle with thefo llowing adap ters:
R Adapter plug
R Adapter cable
The trailer will be cor rectly de tected bytheve hi‐
cle only if thefo llowing conditions are me t:
R The trailer is connected cor rectl y.
R The trailer lighting sy stem is in working
order.
The functions of thefo llowing sy stems will be
af fected bya cor rectly connected traile r:
R ESP ®
trailer stabilisation
R Active Lane Keeping Assist
R Parking Assist PARKTRONIC
R Active Parking Assist
R Blind Spot Assist or Active Blind Spot Assi st
R Drive AwayAssi st
R Cross Traf fic Alert
R Reversing camera
R 360° camera R
AIRMATIC
Coupling up a trailer
* NO
TEDama getothest ar ter battery due
to full discharge Charging
the trailer battery using the po wer
supply of the trailer can damage thest ar ter
batter y. #
Do not use theve hicle's po wer supply
to charge the trailer batter y. #
Remo vethe co ver cap from the ball head and
st ore it in a safe place. #
Position the trailer on a le vel sur face behind
th eve hicle and couple it up totheve hicle. Driving and parking
229

Te
lephone menu overview 1
Blue tooth ®
device name of the cur rently
connected mobile phone
2 Signal stre ngth of the mobile phone network
fo rth e cur rently connected and selected
mobile phone
3 Battery status of the cur rently connected
and selected mobile phone
4 ¢ (telephone ready) or w(call active) 5
Contacts (/page 310)
6 Call list (/ page 312)
7 Text message
8 One mobile phone connected: Active call.
Tw o mobile phones connected: changes view
between telephone 1 and 2 or Active call
9 Devices (/page 305) A
Options
Symbols 1to4 are not shown until af ter a
mobile phone has been connected tothe multi‐
media sy stem. The symbols depend on your
mobile phone and your mobile phone network
pr ov ider. 304
Multimedia sy stem

The Mercedes-Benz emer
gency call sy stem is
av ailable for at least tenye ars starting from the
manufacturing date.
The ignition must be switched on before an auto‐
matic emergency call can be made.
% The Mercedes-Benz emer gency call sy stem
is activated at thefa ctor y.
Overview of the Mercedes-Benz emer gency
call sy stem
The Mercedes-Benz emer gency call sy stem can
help todecisively reduce the time between an
accident and the ar riva l of emer gency services
at the site of the accident. It helps locate an
accident site in places that are dif ficult to
access.
The emer gency call can be made au tomatical ly
( / page 326) or manually (/ page 327). Only
make emer gency calls if you or others are in
need of rescue. Do not make an emergency call
in theeve nt of a breakdown or a similar situa‐
tion.
Displ ays in the media display
SOS READY : eCallavailable SOS NOT READY:
the ignition is not on or eCall
is not available.
During an active emer gency call, Gappears
in the displa y.
Yo u can find more information on there gional
av ailability of eCall at: https://www.mercedes-
benz-mobile.com/ext ra/ecall/
% Ifth ere is a malfunction in the emer gency
call sy stem (e.g. a fault with the speaker,
microphone, airbag, SOS button), a cor re‐
sponding message appears inthe multifunc‐
tion display of the instrument clus ter.
Tr iggering an automatic emer gency call
Re quirements:
R The ignition is switched on.
R The star ter battery is suf ficiently charge d.
If re stra int sy stems such as airbags or seat belt
te nsioners ha vebeen activated af ter an acci‐
dent, the Mercedes-Benz emer gency call sy stem
may automatically initiate an emer gency call. The emergency call has been made:
R
Avo ice connection is made tothe Mercedes-
Benz emer gency call centre.
R A messa gewith accident data is transmitted
to the Mercedes-Benz emer gency call centre.
The Mercedes-Benz emergency call centre
can transmit theve hicle position data toone
of the public emer gency services call cen‐
tres.
R In cer tain situations data is also transmitted
in thevo ice channel tothe Mercedes-Benz
emer gency call centre.
This allo wsmeasu resfo rre scue, reco very or
to wing toa Mercedes-Benz Service Cent reto
be initiated quickl y.
The SOS button in theov erhead control panel
fl ashes until the emer gency call is finished.
It is not possible toimmediately end an auto‐
matic emer gency call.
If th e Mercedes-Benz emer gency call sy stem
cann otconnect tothe Mercedes-Benz emer‐
ge ncy call centre, the emer gency call is au tomat‐ 326
Multimedia sy stem

R
Vehicle identification number
R Vehicle drive type
R Number of people de term ined tobe in the
ve hicle
R Whe ther Mercedes me connect is available
or not
R Whe ther the emer gency call was initiated
manually or automatically
R Time of the accident
R Language setting on the multimedia sy stem
Fo r accident clarification purposes, thefo llowing
measures can be take n up toan hour af terthe
emer gency call has been initia ted:
R The cur rent vehicle position can be de ter‐
mined.
R Avo ice connection totheve hicle occupants
can be es tablished
% ForRu ssia: various functions, e.g. receiving
traf fic information, cannot be used for up to
two hou rsafte r sending an emergency call. Self diagnosis function of
the emer gency call
sy stem
Yo ur car verifies the operability of the emer‐
ge ncy call sy stem each time the ignition is ON.
In case of sy stem failure, you will be informed
with text messa geon the instrument clus ter and
with red indicator SOS NOT READY onthe dis‐
pla y.
Please, make sure, that during 30 seconds af ter
switching ignition ON there d indicator SOS
NOT READY inthe upper right corner of display
is switched OFF, this means the emer gency call
sy stem passed diagnostics successfully.
St arting/ending ERA-GLONASS test mode
Re quirements:
R The star ter battery is suf ficiently charge d.
R The ignition is switched on.
R The vehicle has been stationary for at least
one minute.
% The test mode is cur rently available in the
fo llowing countries, forex ample:
R Russia R
Belarus
R Kazakh stan
R Armenia
R Kyrgyzs tan #
Tostart thete st mode: press and hold the
~ button on the multifunction steering
wheel for at least five seconds.
The test mode is star ted and automatically
ends af terth e language test has been per‐
fo rm ed. #
Toend thete st mode manuall y:switch off
th e ignition.
The test mode is ended. 328
Multimedia sy stem

fi
ed based on the actual operating conditions
and/or loads.
Examples of arduous operating conditions:
R regular city driving with frequent intermedi‐
ate stops
R mainly short-dis tance driving
R frequent operation in mountainous terrain or
on poor road sur faces
R when the engine is of ten le ftidling for long
periods
R operation in particula rly dusty conditions
and/or if air-recirculation mode is frequently
used
In these or similar operating conditions, ha vethe
interior air filter, engine air cleaner, engine oil
and oil filter etc. changed more frequent ly. The
ty re s must be checked more frequently if the
ve hicle is operated under increased loads. Fur‐
th er information can be obtained at a qualified
specialist workshop. Battery disconnection periods
The ASS
YST PLUS service inter val display can
calculate the service due date only when the
battery is connec ted. #
Notedown the service due date displa yed on
th e instrument display before disconnecting
th e battery (/ page 361). Engine compartment
Ac
tive bonn et(pedestrian pr otection) Operation of
the active bonnet (pedestrian
pr otection)
In cer tain accident situations, the actuation of
th e active bonn etreduces therisk of injury to
pedestrians. The rear area of the bonn etis
ra ised byappr oximately 85 mm.
Fo rth e drive tothewo rkshop, reset the actuated
active bonn etyourself (/ page 362).
Af terth e active bonn ethas been actuated,
pedestrian pr otection may be limited.
Ha ve the full functionality of the active bonn et
re stored in a qualified specialist workshop. Re
setting the active bonnet &
WARNING Risk of bu rns from hot com‐
ponent parts in the engine compartment
Cer tain component parts in the engine com‐
partment can be very hot, e.g. the engine,
th e cooler and parts of theex haust sy stem. #
Allow the engine tocool down and only
to uch co mponent parts described in
th efo llowing. 362
Maintenance and care

Battery (vehicle)
Note
s onthe12 V battery &
WARNING Risk of an accident due to
wo rkcar ried out incor rectly on the bat‐
te ry
Wo rkcar ried out incor rectly on the battery
can, forex ample, lead toa short circuit. This
can restrict functions releva nt for saf ety sys‐
te ms and impair the operating saf ety of your
ve hicle.
Yo u could lose cont rol of theve hicle in the
fo llowing situations in particular:
R when braking
R intheeve nt of ab rupt steering manoeu‐
vres and/or when theve hicle's speed is
not adap tedto thero ad conditions #
Intheeve nt of a sho rtcircuit or a simi‐
lar incident, contact a qualified special‐
ist workshop immediately. #
Do not drive on. #
Alw ays ha vewo rkon the battery car ried
out at a qualified specialist workshop. R
Further information on ABS (/ page177)
R Further information on ESP ®
(/ page 177)
Fo r saf etyre asons, Mercedes-Benz recommends
th at you on lyuse bat teries which ha vebeen tes‐
te d and appr ovedfo ryo ur vehicle byMercedes-
Benz.
All vehicles except vehicles with a lithium-
ion battery &
WARNING Risk ofexplosion due toelec‐
tros tatic charge
Electros tatic charge can igni tethe highly
ex plosive gas mixture in the batter y. #
Todischar geany electros tatic charge
th at may ha vebuilt up, touch the me tal
ve hicle body before handling the bat‐
te ry. The highly
flammable gas mixture is created
while the battery is charging and during starting
assis tance. &
WARNING Danger of chemical burns
from the battery acid
Battery acid is caustic. #
Avoid contact with the skin, eyes or
clo thing. #
Do not lean overth e batter y. #
Do not inhale battery gases. #
Keep children away from the batter y. #
Immedia tely rinse battery acid off thor‐
oughly with plenty of clean water and
seek medical attention immediately. Breakdown assi
stance 385

All
vehicles
+ ENVIRONMENTAL
NOTEEnvironmental
dama gedue toimproper disposal of bat‐
te ries Batteries conta
in pollutants. It is
illegal todispose of them with the household
ru bbish. #
Dispose of batteries in an
environmen tally responsible manner.
Ta ke dischar ged batteries toaqu alified
specialist workshop or toa collection
point for used batteries. If
yo u ha vetodisconnect the12 V batter y,con‐
ta ct a qualified specialist workshop.
Comply with saf ety no tes and take protective
measures when handling batteries. Risk of
explosion. Fire, naked
flames and smoking are
prohibi ted when handling the batter y.
Av oid creating spar ks. Electrolyte
or battery acid is cor ro‐
sive. Avoid contact with the skin, eyes
or clo thing. Wear suitable pr otective
clo thing, in particular glove s, an
apron and a face mas k.Immedia tely
ri nse electrolyte or acid splashes off
with clean water.Consult a doc tor if
necessar y. We
ar saf etygl asses. Ke
ep children away. Obser
vethis Owner's Manual.
Obser vethefo llowing if you do not intend touse
th eve hicle over an extended pe riod of time:
R Activate standby mode.
R Alternatively: connect the battery toa bat‐
te ry charge r appro vedby Mercedes-Benz or
consult a qualified specialist workshop to
disconnect the batter y. Note
s onstarting assi stance and charging
th e12 V battery Ve
hicles with a lithium-ion battery
When charging the battery and during starting
assis tance, al ways use the jump-s tart connec‐
tion point in the engine compartment. 386
Breakdown assis tance

*
NO
TEDama getothe battery from over‐
vo ltage When
charging using a bat tery charge r with‐
out a restriction of the maximum charging
vo ltage, the battery or the on-board electron‐
ics can be damaged. #
Only use battery charge rs with a maxi‐
mum charging voltage of 14.8 V. All
other vehicles
When charging the battery and during starting
assis tance, al ways use the jump-s tart connec‐
tion point in the engine compartment.
* NO
TEDama getothe battery from over‐
vo ltage When
charging using a bat tery charge r with‐
out a restriction of the maximum charging
vo ltage, the battery or the on-board electron‐
ics can be damaged. #
Only use battery charge rs with a maxi‐
mum charging voltage of 14.8 V. &
WARNING Risk ofexplosion from hydro‐
ge nga s igniting
There is a danger of hydrogen gas igniting
when charging the battery if there is a short
circuit or spar ksstart toform. #
Make sure that the positive term inal of
th e connected battery does not come
into conta ct withvehicle parts. #
Never place me tal objects or tools on a
batter y. #
The described order of the battery
clamps must be obser ved when con‐
necting and disconnecting the batter y. #
When giving starting assis tance, al ways
make sure that you on lyconnect bat‐
te ry term inals with identical polarity. #
During starting assis tance, you must
obse rveth e described order for con‐
necting and disconnecting the jump
lead. #
Do not connect or disconnect the bat‐
te ry cla mp s while the engine is running. &
WARNING Risk ofexplosion during
ch arging process and starting assis tance
During thech arging process and starting
assis tance, the battery may release an explo‐
sive gas mixture. #
Avoid fire , naked flames, creating
spar ksand smoking. #
Make sure there is suf ficient ventila‐
tion. #
Do not lean over a batter y. &
WARNING Risk ofexplosion from a fro‐
zen battery
A dischar ged battery may freeze at temp era‐
tures slightly abo veor below freezing point.
During starting assis tance or battery charg‐
ing, bat tery gas can be released. #
Alw ays allow a battery tothaw before
ch arging it or per form ing starting assis‐
ta nce. Breakdown assi
stance 387