2021 MERCEDES-BENZ A-CLASS HATCHBACK jump start

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

V
V
ehicle
ehicle Displa
Displa
y messag
y messag es P
es Possible causes/conseq
ossible causes/conseq uences and
uences andM
MSolutions
Solutions
d
Vehicle is operational
Switch off ignition before
exiting *Y
ou are leaving theve hicle in a ready-to-drive state. #
Get out of theve hicle, secure it against rolling away and take theke y with you. #
Ifyo u do not lea vetheve hicle, switch o. the electrical consumers, e.g. the seat heating. Otherwise, the 12‑V bat-
te ry may dischar geand starting the engine may be possible only with the help of a second battery (jump start).
ï
Check trailer hitch
lock (white display message) *T
he trailer hitch is not operational during a jou rney with a trailer. &
W WARNING
ARNING Risk of an accident if the ball neck is not loc ked
The trailer may become de tach ed. #
Stop theve hicle immediately in accordance with the tra1c conditions. Do not continue driving. #
Uncouple the trailer and secure it against rolling away. #
Initiate a new swivelling procedu reand do not re-couple the trailer until the display message disappears. #
Initiate a new swivel mo vement (/ page 271). #
When the display message disappears, couple up the trailer and drive on.
If th e display message does not disappear, the trailer hitch is malfunctioning and the ball neck is not loc ked. Display messages and
warning/indicator lamps
429
429

Con
venience closing............................... .94
Con venience opening.............................. .94
Opening with theke y................................ 94
Opening/closing...................................... 92
Problem................................................... 95
Ra in closing function................................ 93
Sliding sunr Sliding sunr oof
oof
Au tomatic functions................................. 98
Closing................................................... .95
Closing using theke y............................... 94
Opening................................................... 95
Opening wi th theke y................................ 94
Problem................................................... 99
Ra in-closing feature................................ .98
Smar
Smar tphone
tphone
see Sma rtphone integ ration
see Telephone
Smar
Smar tphone int
tphone int egr
egration
ation
Overview................................................ 319
Sno
Sno w c
w chains
hains................................................3 68
Soc ke
Soc ket (12 V)
t (12 V)
Boot/luggage compartment................... 128
Fr ont centre console.............................. 128 Soc
ke
Soc ket (115 V)
t (115 V)
Re ar....................................................... 129
SoTw
SoTw are
areupdate
update
System updates.................................... .294
Sound
Sound PRE-SAFE ®
Sound................................... 60
Sound menu
Sound menu Functions overview................................ 329
Spar
Spar e wheel
e wheel
see Collapsible spare wheel
see Emer gency spa rewheel
Specialis
Specialis t w
t work
ork shop
shop
see Quali/ed specialist workshop
Speci/c
Speci/c absorp
absorption r
tion rate
ate................................. 29
Speed Limit Assist
Speed Limit Assist Function/no tes...................................... 246
Setting................................................... 247
System limitations.................................. 246
Speed limit f
Speed limit f or wint
or winter tyr
er tyres
es
Setting................................................... 232
St St andb andb y mode
y mode
Ac tivating/deactivating.......................... 219
Fu nction................................................ 218 S
S
t
tanding lights
anding lights............................................ .134
St
St ar
art-o.
t-o. assist
assist
Ac tivating............................................... 227
Fu nction................................................ 227
St
St ar
art/st
t/st op butt
op butt on
on
Pa rking theve hicle................................. 211
St arting theve hicle............................... .166
Switching on the po wer supply/vehicle.. 165
St
St ar
art/st
t/st op function
op function
see ECO start/stop function
St
St art
art er batt
er batt ery
ery
Charging (Remo teOnline)..................... .167
St
St ar
arting
ting
see Vehicle
St
St ar
arting assist
ting assist ance
ance
see Jump-start connection
St
St ar
arting-o.
ting-o. aid
aid
see Hill Start Assist
St
St ationar
ationar y heat
y heat er/v
er/ventilation
entilation
Ac tivating/deactivating (control panel)... 159
Setting (MBUX multimedia system)......... 160
S
S TEER C
TEER C ONTR
ONTROL
OL
Fu nction/no tes...................................... 224 520
520
Index