2021 MERCEDES-BENZ A-CLASS HATCHBACK battery

switched OFF,
this means the emer gency call sys-
te m passed diagnostics successfull y.S
S
t
tar
ar ting/ending ERA
ting/ending ERA -GL
-GLON
ONASS t
ASS t es
est mode
t mode R
R
eq
eq uir
uir ements:
ements:
R The star ter battery is su1ciently charge d.
R The vehicle is switched on.
R The vehicle has been stationary for at least
one minute.
% The test mode is cu rrently available in thefo l-
lowing countries, forex ample:
R Russia
R Belarus
R Kazakhstan
R Armenia
R Kyrgyzs tan #
T
To st
o st ar
art t
t t he t
he t es
est mode:t mode: press and hold the
~ button on the multifunction steering
wheel for at least /ve seconds.
The test mode is star ted and automatically
ends aTer the language test has been pe r-
fo rm ed. #
T
To st
o st op manual t
op manual t es
est mode:t mode: switch o. theve hi-
cle.
The test mode is ended. MBUX multimedia system
323 323

R
Frequent operation in mountainous terrain or
on poor road sur faces
R When the engine is oTen leT idling for long
periods
R Operation in particular lydusty conditions
and/or if air-recirculation mode is frequently
used
In these or similar operating conditions, ha vethe
interior air /lter, air /lter, engine oil and oil /lter,
fo rex ample, changed more frequentl y.The tyres
must be checked more frequently if theve hicle is
operated under increased loads. Further informa-
tion can be obtained at a quali/ed specialist work-
shop. Batt Batt
er
ery disconnection per
y disconnection per iods
iodsThe AS
SYST PLUS service inter val display can cal-
culate the service due date only when the battery
is connected. #
Display and no tedown the service due date
on the inst rument display before disconnect-
ing the battery (/ page 330). Engine com
Engine com
par
partment
tment A
A
ctiv
ctiv e bonne
e bonne t (pedes
t (pedestr trian pr ot
ian pr otection)
ection) Oper
Oper
ation of t
ation of t he activ
he active bonne
e bonne t (pedes
t (pedestr trian pr ot
ian pr otec-
ec-
tion)
tion)
In cer tain accident situations, the actuation of the
active bonnet reduces therisk of injury topedes-
trians. The rear area of the bonnet is raised by
appr oximately 70 mm.
Fo rth e drive tothewo rkshop, reset the actuated
active bonnet yourself (/ page 331).
ATer the active bonnet has been actuated, pedes-
trian pr otection may be limited.
Ha ve the full functionality of the active bonnet
re stored in a quali/ed specialist workshop.
R
R ese ese tting t
tting t he activ
he activ e bonnet
e bonnet &
W
WARNING
ARNING Risk of burns from hot compo-
nent parts in the engine compartment
Cer tain component parts in the engine com-
partment can be very hot, e.g. the engine, the
cooler and parts of theex haust system. #
Allow the engine tocool down and only
to uch component parts described in the
fo llowing. #
With your hand 0at, push down active bonnet
1 inthe area around the hinges on bo th
sides (ar rows ).
In doing so, the actuator is depressurised and
yo u may hear a hissing sound.
The engine bonnet must engage in position. #
Ifth e active bonnet can be raised slightly at
th ere ar in the area of the hinges, repeat the
step until it engages co rrectl y. Maintenance and ca
re
331
331

#
T
To r
o r educe t
educe t he tyr
he tyre pr
e pressur
essur e:
e:press pressure
re lease button 1next tomanome ter2. #
When the tyre pressure is cor rect, unscr ew
th e /lling hose from theva lve of the sealed
tyre. #
Screw theva lve cap onto theva lve of the
sealed tyre. #
Pull the tyre sealant bottle out of the tyre in0a-
tion compressor.
The /lling hose st ays on the tyre sealant bot-
tle. #
Drive tothe nearest quali/ed specialist work-
shop and ha vethe tyre, tyre sealant bottle and
/lling hose replaced there. Batt
Batt
er
ery (v
y (v ehicle)
ehicle) N
No
ot
tes on t
es on t he 12 V batt
he 12 V batt ery
ery &
W
WARNING
ARNING Risk ofexplosion due toelec-
trostatic charge
Electrostatic charge can ignite the highly
ex plosive gas mixtu reinthe batter y. #
Todischar geany elect rostatic charge
th at may ha vebuilt up, touch the me tal
ve hicle body before handling the batter y. The high
ly0ammable gas mixtu reis created while
th e battery is charging and during starting assis-
ta nce. &
W
WARNI NG
ARNI NGDanger of chemical burns from
th e 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. #
Immediately rinse bat tery acid o. thor-
oughly with plenty of clean water and
seek medical attention immediatel y. +
ENVIR
ENVIR
ONMENT
ONMENT AL NO
AL NOTE
TEEnvironmen tal
damage due toimproper disposal of bat-
te ries Batteries contain pollutants. It is
illegal todispose of them with the household
ru bbish. #
Dispose of batteries in an
environmentally responsible manner.
Ta ke dischar ged batteries toaqu ali/ed
specialist workshop or toa collection
point for used batteries. If
yo u ha vetodisconnect the 12 V batter y,con-
ta ct a quali/ed specialist workshop.
Comply with saf ety no tes and take protective
measures when handling batteries. 354
354
Breakdown assistance

Risk of
explosion. Fire
, naked 0ames and smoking are
prohibi ted when handling the batter y.
Av oid creating spar ks. Electrolyte or battery acid is cor
rosive.
Av oid contact with the skin, eyes or
clo thing. Wear suitable pr otective
clo thing, in particular glo ves, an apron
and a face mask. Immediately rinse
electrolyte or acid splashes o. with
clean water. Consult a doctor if neces-
sar y. We
ar saf ety glasses. Ke
ep children away. Obser
vethis Owner's Manual.
If yo u do not intend touse theve hicle over an
ex tended period of time:
R activate standby mode, or
R connect the battery toa battery charger
appr ovedby Mercedes-Benz, or
R consult a quali/ed specialist workshop todis-
connect the battery N No
ot
tes on st
es on st ar
arting assist
ting assist ance and c
ance and c har
harging t
ging t he 12
he 12
V batt
V batt ery
ery When
charging the battery and during starting
assistance, alw ays use the jump-start connection
point in the engine compartment.
* N
NOOTE
TE Damage tothe battery from over-
vo ltage When
charging using a battery charge r without
a re striction of the maximum charging voltage, th
e battery or the on-board electronics can be
damaged. #
Only use battery charge rs with a maxi-
mum charging voltage of 14.8 V. &
W
WARNI NG
ARNI NGRisk of explosion due tohydro-
ge nga s igniting
If, when charging a batter y,there is a short
circuit or spar ksstart toform ,th ere is a dan-
ge r of hydrogen gas igniting. #
Take care that the positive clamp con-
nected toa battery does not come into
contact with vehicle parts. #
Never place me tal objects or tools on a
batter y. #
When connecting and disconnecting the
batter y,alw ays obser vethe sequence of
battery clamps described. #
Take care toonly connect battery term i-
nals of identical polarity when receiving
starting assistance. Breakdown assistance
355
355

#
Obser vethe sequence described for
connecting and disconnecting the jump
leads when receiving starting assistance. #
Do not connect or disconnect the bat-
te ry term inals while the engine is run-
ning. &
W
WARNI NG
ARNI NGRisk of explosion due toexplo-
sive mixture of gases
An explosive mixture of gases can escape
from the battery during charging and starting
assis tance. #
Fire , naked 0ames, smoking and creating
spar ksmust be avoided. #
Make sure there is adequate ventilation. #
Do not stand overth e batter y. &
W
WARNI NG
ARNI NGRisk of explosion from a frozen
battery
A dischar ged battery may freeze at temp era-
tures slightly abo veor below freezing point. During starting assistance or battery
charging,
battery gas can be released. #
Always allow a battery tothaw before
ch arging it or per form ing starting assis-
ta nce. If
th e indicator/warning lamps in the instrument
cluster do not light up at low temp eratures, it is
ve ry likely that the dischar ged battery has frozen.
In this case you may neither jump-start theve hi-
cle nor charge the batter y.
The service life of a bat tery that has been thawed
may be dramatically shor tened. The starting char-
acteristics may be impaired, especially at low
te mp eratures.
It is recommended that you ha veath awe d battery
ch ecked at a quali/ed specialist workshop.
* N
NO OTE
TE Damage caused bynume rous or
ex tended attem ptsto start the engine Numerous or
extended attem ptsto start the
engine may damage the catalytic con verter
due tonon-combusted fuel. #
Avoid numerous and extended attem pts
to start the engine. Obser
vethefo llowing points during starting assis-
ta nce and when charging the batter y:
R Only use undamaged jump lead/charging
cables with a su1cient cross-section and
insulated term inal clamps.
R Non-insulated parts of thete rm inal clamps
must not come into contact with other me tal
parts while the jump lead/charging cable is
connected tothe battery/jump-start connec-
tion point.
R The jump lead/charging cable must not come
into contact with any parts which may mo ve
when the engine is running.
R Always make sure that nei ther you nor the bat-
te ry is electros tatically charge d.
R Keep awa y from /re and naked 0ames.
R Do not lean overth e batter y. 356 356
Breakdown assistance

Obser
vethe additional following points when
ch arging the batter y:
R Only use battery charge rs tested and
appro vedfo r Mercedes-Benz.
R Read the battery charge r's operating inst ruc-
tions before charging the batter y.
Obser vethe additional following points during
starting assistance:
R For starting assistance, only use batteries with
a nominal voltage of 12 V.
R The vehicles must not touch.
R P
P e
e tr
tr ol engine:
ol engine: only accept starting assistance
if th e engine and exhaust system are cold. S
S
t
tar
ar ting assist
ting assist ance and c
ance and c har
harging t
ging t he 12 V batt
he 12 V batt ery
ery R
R
eq
eq uir
uir ements:
ements:
Plug-in h
Plug-in h ybr
ybrid:
id:in order tostart, theve hicle
re qu ires a su1cient charge leve l of the high-volt-
age battery as well as a su1cient po wer output of
th e 12 V on-board electrical system.
R The vehicle is secured with the electric par k-
ing brake. R
A Aut ut omatic tr
omatic tr ansmission:
ansmission: the transmission is in
position j.
R Manual tr
Manual tr ansmission:
ansmission: the transmission is in
neutral.
R The vehicle and all elect rical consume rsare
switched o..
R The bonnet is open. #
Slide co ver1 of positive clamp 2onthe
jump-starting connection point in the direction
of the ar row. #
Connect positive clamp 2onyour vehicle to
th e positive pole of the donor battery using
th e jump lead/charging cable. Alw ays begin
with positive clamp 2onyour ow nve hicle
/rst. #
Dur
During st
ing st ar
arting assist
ting assist ance:
ance:startthe engine of
th e donor vehicle and run at idle speed. #
Connect the negative pole of the donor bat-
te ry and ear thpoint 3ofyour ow nve hicle by
using the jump lead/charging cable. Begin
with the donor battery /rst. #
Dur
During st
ing st ar
arting assist
ting assist ance:
ance:startthe engine of
yo ur ow nve hicle. #
Dur During t
ing t he c
he char
harging pr
ging pr ocess:
ocess: startthech arg-
ing process. #
Dur During st
ing st ar
arting assist
ting assist ance:
ance:letthe engines run
fo r se veral minutes. #
Dur During st ing st ar
arting assist
ting assist ance:
ance:before disconnect-
ing the jump lead, switch on an electrical con- Breakdown assistance
357
357

sumer on
your ow nve hicle, e.g. there ar win-
dow heater or lighting.
When the starting assistance/charging process is
comple te: #
Firs t, re mo vethe jump lead/charging cable
from ear thpoint 3and the negative pole of
th e donor batter y,then from positive clamp
2 and the positive pole of the donor batter y.
Begin ea chtime with the contacts on your
ow nve hicle /rst. #
ATer removing the jump lead/charging cable,
close co ver1 of positive clamp 2.
Plug-in h
Plug-in h ybr
ybrid:
id:ifyo ur vehicle has been star ted
with starting assis tance, it may not be possible to
use the electric drive for appr oximately 30
minutes.
Fu rther information can be obtained at a quali/ed
specialist workshop. R R
eplacing t
eplacing t he 12 V batt
he 12 V batt ery
ery #
Obser vethe no tes on the 12 V battery
(/ page 354). Mercedes-Benz
recommends that you ha vethe
12 V battery replaced at a quali/ed specialist
wo rkshop, e.g. at a Mercedes-Benz Se rvice
Centre.
Obser vethefo llowing no tes if youwa nttoreplace
th e battery yourself:
R Alwaysre place a faulty battery with a battery
which meets the speci/c vehicle requ ire-
ments.
The vehicle is equipped with a 0eece batter y.
Fu llve hicle functionality is only guaranteed
with a 0eece batter y.Fo r saf etyre asons,
Mercedes-Benz recommends that you only
use batteries which ha vebeen tested and
appro vedfo ryo ur vehicle byMercedes-Benz.
R Use de tach able parts such as vent hoses,
elbow /ttings or term inal co vers from the bat-
te ry which is tobe replaced.
R Make sure that theve nt hose is alw ays con-
nected tothe original opening on the side of
th e batter y.
Fi t any existing or supplied cell caps.
Otherwise, gases or battery acid could
escape. R
Make sure that de tach able parts are recon-
nected in the same way. T T
o
o w
w -st
-st ar
arting or to
ting or towing away
wing away P
P
er
er mitt
mitt edto
ed towing met
wing met hods (non plug-in h
hods (non plug-in h ybr
ybrid)
id) Mercedes-Benz
recommends transporting your
ve hicle in the case of a breakdown, rather than
to wing it away.
Fo rto wing, use a tow rope or tow bar with bo th
axles on thegr ound. Do not use tow bar systems. &
W
WARNING
ARNING Risk of accident when towing
with steering wheel lock
If th e steering wheel lock is engaged, you will
not be able tosteer theve hicle. #
When towing with a tow rope or tow bar,
alw ays switch on theve hicle. *
N NOOTE TE Damage totheve hicle due to tow-
ing awa y incor rectly #
Obser vethe inst ructions and no tes on
to wing away. 358 358
Breakdown assistance

P
P
er
er mitt
mitt edto
ed towing met
wing met hods
hods V
V
ehicle eq
ehicle eq uipment/to
uipment/to wing met
wing method
hod Bot
Bot
h axles on t
h axles on t hegr
he ground
ound F
F
r
ront axle r
ont axle r aised
aised R
R
ear axle r
ear axle r aised
aised
Plug-in hybrid vehicles Yes, maximum 50 km at 50 km/h Yes, maximum 50 km at 50 km/h Yes, maximum 50 km at 50 km/h
The steering wheel must be /xed in
th e centre position with a steering
wheel loc k. In
thefo llowing situations, only transporting the
ve hicle is permitted:
R the multifunction display is not working
or
R theá Towing not permitted See Owner's
Manual display message appears
Ex Ex cep
cep tion:
tion: ifth eve hicle is located in a danger
zone, it can be reco vered from the danger zone
despite the display message or the display not
wo rking. It must not be
towe d fur ther than 50 m with bo th
axles on thegr ound. A towing speed of 10 km/h
must not be exceeded. Be yond these limits, only
transporting is permitted. T
T
o
o wing t
wing t he v
he vehicle wit
ehicle wit h bot
h both axles on t
h axles on t hegr
he ground
ound #
Obser vethe no tes on the permitted towing
me thods (/ page 358). #
Plug-in hybrid: obser vethe no tes on the per-
mitted towing me thods (/ page 359). #
Make sure that the battery is connected and
ch arge d.
Obser vethefo llowing points when the battery is
dischar ged:
R theve hicle cann otbe star ted
R the electric parking brake cannot be released
or applied
R V
Vehicles wit
ehicles wit h aut
h automatic tr
omatic tr ansmission:
ansmission: the
transmission cannot be shiTed toposition i
or j. 360
360
Breakdown assistance