2021 MERCEDES-BENZ A-CLASS HATCHBACK key battery

Go
vernmental entities are themsel ves, in individ-
ual cases and within the applicable legal frame-
wo rk, authorised toread out data from theve hi-
cle. In the case of an accident, information that
can help with an in vesti gation can, therefore, be
ta ke n from the airbag control unit, forex ample.
Oper
Oper ational dat
ational dat a in t
a in the v
he vehicle
ehicle
This is data rega rding the operation of theve hicle,
which ha vebeen processed bycont rol units.
This includes thefo llowing data, forex ample:
R vehicle status information such as the speed,
longitudinal acceleration, lateral acceleration,
number of wheel revo lutions or thefa stened
seat belts display
R ambient conditions, su chastemp erature, rain
sensor or distance sensor
Generall y,the use of these data is temp orar y;
th ey will not be stored be yond the period of oper-
ation and will only be processed within theve hicle
itself. Control units oTen contain data memories
fo rve hicle keys,fo rex ample. Their use permits
th ete mp orary or permanent documentation of
te ch nical information about theve hicle's operat- ing state, component loads, main
tenance requ ire-
ments and tech nical events or faults.
Depending on theve hicle equipment, thefo llo w-
ing data are stored:
R operating status of system components, such
as /ll le vels, tyre pressure or battery status
R malfunctions or faults in impor tant system
components, such as lights or brakes
R system reactions in special driving situations,
such as airbag depl oyment or the inter vention
of stability cont rol systems
R information on events leading tovehicle dam-
age
In cer tain cases, it may be requ ired tostore da ta
th at wo uld ha veotherwise been used only temp o-
rari ly. This may be the case if theve hicle has
de tected a malfunction, forex ample.
If yo u use services, such as repair services and
maintenance work, stored operational data as
we ll as theve hicle identi/cation number can be
re ad out and used. They can be read out by
service network emplo yees, such as workshops
and manu facturers or third parties, such as break- down services. The same is true in
the case of
wa rranty claims and quality assurance measures.
In general, there adout is per form ed via the legally
prescribed port forth e diagnostics connection in
th eve hicle. The operational data that are read out
document tech nical states of theve hicle or of
individual components and assist in the diagnosis
of malfunctions, compliance with warranty obli ga-
tions and quality impr ovement. Tothat end, these
data, in particular information about component
loads, tech nical events, malfunctions and other
fa ults may be transmitted along with theve hicle
identi/cation number tothe manufacturer. Fur-
th ermore, the manufacturer is subject toproduct
liability. Forth is reason the manufacturer also
uses operational data from theve hicle, forex am-
ple, forre calls. These data can also be used to
ex amine the customer's warranty and guarantee
claims.
Fa ult memories in theve hicle can be reset by a
service outl etor at your requ est as part of repair
or maintenance work. General no
tes
43 43

K
K
e
ey
y Ov
Ov
er
ervie
vie w of ke
w of key functions
y functions &
W
WARNING
ARNING Risk of accident and inju rydue
to leaving children unattended in theve hi-
cle
If ch ildren are leT unattended in theve hicle,
th ey could, in particular:
R open doors, thereby endangering other
persons or road users.
R get out and be struck byoncoming tra1c.
R operate vehicle equipment and become
trapped, forex ample.
In addition, thech ildren could also set the
ve hicle in motion by,fo rex ample:
R releasing the parking brake.
R changing the transmission position.
R starting theve hicle. #
Never lea vechildren unattended in the
ve hicle. #
When leaving theve hicle, alw aysta ke the
ke y with you and lock theve hicle. #
Keep theve hicle key out of there ach of
ch ildren. *
N
NOOTE
TE Damage totheke y caused bymag-
netic /elds #
Keep theke yaw ay from strong magnetic
/elds. Ve
hicle key
1 Locks 2
Indicator lamp
3 Unloc ks
% If indicator lamp 2does not light up aTer
pressing theÜ orß button, the battery
is we ak or possibly dischar ged. Re place the
battery as soon as possible.
Re place theke y battery (/ page 84).
The key loc ksand unloc ksthefo llowing compo-
nents:
R Doors
R Fuel /ller 0ap
R Soc ket 0ap (plug-in hybrid)
R Tailgate
If th eve hicle is not opened within appr oximately
40 seconds aTer unlocking, it loc ksagain. Anti-
th eT pr otection is primed again.
Do not keep theke yto get her with elect ronic devi-
ces or me tal objects. This can a.ect theke y's
functionalit y. 82 82
Opening and closing

R
R
emo
emo ving/inser
ving/inser ting t
ting the emerg
he emerg encykey
ency key R R
emo emo ving t
ving t he emerg
he emerg encykey
ency key #
Press release button 1.
Emer gency key2 is pushed out slightl y.#
Pull out eme rgency key2 until it en gage s in
th e intermediate position.
% Depending on theve hicle's equipment, the
intermediate position is not available. #
Press release button 1again and fully
re mo veemer gency key2. Inser
Inser
ting t
ting t he emerg
he emerg encykey
ency key #
Press release button 1. #
Insert emer gency key2 tothe intermediate
position or fully until it engages.
% You can use the intermediate position of
emer gency key2 toattach theke yto akey
ri ng. R
R
eplacing t
eplacing t heke
he key batt
y batt ery
ery &
D
DAN
AN GER
GER Risk of fatal injuries due toswal-
lowing batteries
Bat teries contain toxic and cor rosive subs tan-
ces. Swall owing batteries may cause se vere
internal burns tooccur within two hours.
There is a risk of fatal injur y. #
Keep batteries out of there ach of chil-
dren. #
Ifth e cap and/or the battery compart-
ment does not close securel y,do not use
th eke y any lon ger and keep it out of the
re ach of children. #
If batteries are swallo wed, 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. R
R
eq
eq uir
uir ements:
ements:
R Youre qu ire a CR 2032 3 V cell batter y.84
84
Opening and closing

Mercedes-Benz
recommends that you ha vethe
battery replaced at a quali/ed specialist work-
shop. #
Remo vethe emer gency key (/ page 84). #
Press release knob 2down fully and slide
co ver1 inthe direction of the ar row. #
Fold out co ver1 inthe direction of the ar row
and remo ve. #
Remo vebattery compartment 3and take
out the dischar ged batter y. #
Insert the new battery into battery compart-
ment 3. Obser vethe positive pole marking in th
e battery compartment and on the battery
when doing this. #
Push in battery compartment 3. #
Re-attach co ver1 and push it until it
engages. Pr
Pr
oblems wit
oblems wit h t
h the key
he key , tr
, troubleshoo
oubleshoo ting
ting Y
Y
ou can no long
ou can no long er loc
er lock or unloc
k or unloc k t
k the v
he v ehicle
ehicle
Po ssible causes:
R The key battery is weak or dischar ged. #
Check the battery using the indicator lamp
(/ page 82). #
Replace theke y batter y,if necessary
(/ page 84). #
Use there placement key. #
Use the emer gency keyto lock or unlock
(/ page 89). #
Have theke ych ecked at a quali/ed specialist
wo rkshop. Ther
Ther
e is int
e is int erf
erfer
erence fr
ence fr om a pow
om a pow er
erful r
ful r adio signal
adio signal
sour
sour ce
ce
Po ssible causes if the function of theke y is
impaired:
R high voltage po wer lines
R mobile phones
R electronic devices (no tebooks, tablets)
R shielding due tome tal objects or induction
loops for electrical gate systems or automatic
bar riers #
Make sure that there is su1cient distance
between theke y and the po tential sou rce of
inter fere nce.
Y
Y ou hav
ou hav e los
e lost a key
t a key #
Have theke y deactivated at a quali/ed spe-
cialist workshop. #
If necessar y,ha ve the mechanical lock
re placed as well. Opening and closing
85
85

#
T To unloc o unloc k t
k the v
he v ehicle:
ehicle: touch the inner sur face
of the door handle. #
T To loc o loc k t
k the v
he v ehicle:
ehicle: touch sensor sur face 1
or 2. #
Conv Conv enience closing:
enience closing: touch recessed sensor
sur face 2 until the closing process has been
comple ted. %
Further information on con venience closing
(/ page 94).
If yo u open theta ilgate from outside, it is auto-
matically unloc ked. Pr Pr
oblems wit
oblems wit h KEYLESS-GO, tr
h KEYLESS-GO, tr oubleshoo
oubleshooting
ting Y
Y
ou can no long
ou can no long er loc
er loc k or unloc
k or unloc k t
k the v
he v ehicle using
ehicle using
KEYLESS-GO
KEYLESS-GO
Po ssible causes:
R The function of theke y has been deactivated.
R The key battery is weak or dischar ged. #
Activate the function of theke y (/ page 83). #
Check the battery using the indicator lamp
(/ page 82). #
Replace theke y batter y,if necessary
(/ page 84). #
Use there placement key. #
Use the emer gency keyto lock or unlock
(/ page 89). #
Have theve hicle and keych ecked at a quali-
/ed specialist workshop. Ther Ther
e is int
e is int erf
erfer
erence fr
ence fr om a pow
om a pow er
erful r
ful r adio signal
adio signal
sour
sour ce
ce
Po ssible causes if the function of KEYLESS-GO is
impaired:
R high voltage po wer lines
R mobile phones
R electronic devices (no tebooks, tablets)
R shielding due tome tal objects or induction
loops for electrical gate systems or automatic
bar riers #
Make sure that there is su1cient distance
between theke y and the po tential sou rce of
inter fere nce. A
A
ctiv
ctiv ating/deactiv
ating/deactiv ating t
ating the aut
he automatic loc
omatic loc king f
king fea-
ea-
ture
ture The
vehicle is loc ked automatically when theve hi-
cle is switched on and the wheels are turning
fa ster than walking pace. 88
88
Opening and closing

#
T
To int
o int err
errup
upt conv
t conv enience closing:
enience closing: release the
ß button. #
T
To continue conv
o continue conv enience closing:
enience closing: press and
hold theß button again.
% Con venience closing also functions with KEY-
LESS-GO (/ page 87). R
R
esol
esol ving pr
ving pr oblems wit
oblems wit h t
h the side wind ows
he side wind ows &
W
W ARNI NG
ARNI NGRisk of becoming trapped or
fata lly injured if reve rsing pr otection is not
activated
If yo u close a side window again immediately
aTer it has been bloc ked, the side window will
close with increased or maximum forc e. The
re ve rsing function is then not active and body
parts may become trapped. #
Make sure that no parts of the body are
in the closing area. #
Tostop the closing process, release the
button or press the button again to
re open the side windo w. A side windo
A side windo
w canno
w cannot be closed and y
t be closed and y ou cannot
ou cannot
see t
see t he cause.
he cause. #
Che cktosee whe ther any objects are in the
wind owguide. #
Adjust the side windo ws.
A
A djus
djus ting t
ting t he side window
he side window s
s
If a side window is obstructed during closing and
re opens again immediatel y: #
Immediately aTer this, pull and hold the cor re-
sponding button again until the side window
has closed and hold the button for at least one
more second (re-adjustment).
The side window will be closed without the
automatic reve rsing function.
If th e side window is obstructed again and
re opens again immediatel y: #
Immediately aTer this, pull and hold the cor re-
sponding button again until the side window
has closed and hold the button for at least one
more second (follo w-up adjustment).
The side window will be closed without the
automatic reve rsing function. The side window
The side window s canno s cannot be opened or closed
t be opened or closed
using t
using t he conv
he conv enience opening f
enience opening f eatur
eature.
e.
Po ssible causes:
R The key battery is weak or dischar ged. #
Check the battery using the indicator lamp
(/ page 82). #
Replace theke y batter y,if necessary
(/ page 84). Sliding sunr
Sliding sunr
oof
oof Opening and closing t
Opening and closing t
he sliding sunr
he sliding sunroof
oof %
The term "sliding sunroof" also refers to the
panorama sliding sunroof. &
W
WARNING
ARNING Risk of becoming trapped when
th e sliding sunroof is being opened and
closed
Body parts may become trapped in thera nge
of mo vement. Opening and closing
95
95

imately 30 minutes, depending on
thete mp era-
ture set. #
T
To activ
o activ at
ate:
e: press the Á button.
Re sidual heat will be switched o. automaticall y.Pr
Pr
e-entr
e-entr y climat
y climat e contr
e control using t
ol using t hekey
he key F
F
unction of pr
unction of pr e-entr
e-entry climat
y climat e contr
e control using t
ol using t he
he
key
key
Before entering theve hicle, the driver's seat area
or the whole vehicle interior can be brie0y pre-
wa rmed or pre-cooled.
When pre-cooling, thefo llowing functions are acti-
va ted as needed:
R Automatic climate control
R Blower
R Seat ventilation
When pre-heating, thefo llowing functions are acti-
va ted as needed:
R Automatic climate control
R Blower
R Seat heater R
Steering wheel heater
R Mirror heater
R Rear wind owheater
Se
Se tting pr tting pr e-entr
e-entry climat
y climat e contr
e control via t
ol via thekey
he key
Multimedia system:
4 Climate menu 5
Pre-entry climate ctrl
Switc
Switc hing
hingon/o.
on/o. #
Select Z. #
Select Pre-entry climate control via key.
Switc
Switc hing pr
hing pr e-entr
e-entry climat
y climat e contr
e control via t
ol via thekey
he key
on/o.
on/o.
R R eq
eq uir
uir ements:
ements:
R The high-voltage battery is charge d su1-
cient ly.
R The function has been activated via the multi-
media system. #
T
T o switc
o switc h on:
h on:unlock theve hicle.
The climate cont rol functions are activated for
up to/ve minutes for pre-heating and pre-
cooling. Pre-entry climate control via
theke y cann otbe
activated more than twice when theve hicle is
switched o.. #
T
To switc
o switc h
h o.:
o.: push the& button up or
down.
The following functions will remain active once the
ve hicle has been star ted:
R Seat heating
R Seat ventilation Pr
Pr
e-entr
e-entr y climat
y climat e contr
e control at depar
ol at depar tur
ture time
e time Pr
Pr
e-entr
e-entr y climat
y climat e contr
e control f
ol f or depar
or depar tur
ture time func-
e time func-
tion
tion &
W
WARNI NG
ARNI NGRisk of fatal injury due toexpo-
sure toextreme heat or cold in theve hicle
If persons, particular lych ildren, are subjected
to prolonged exposure tointense heat or cold,
th ere is a risk of se vere injury or even death. #
Never lea vepersons, particular lych il-
dren, unattended in theve hicle. 156
156
Climate cont
rol

%
The electric parking brake is only securely
applied if there d! indicator lamp is lit
continuousl y.
R
R eleasing eleasing #
Switch on theve hicle. #
Pull handle 1.
The red! indicator lamp in the inst rument
clus ter goes out.
Emerg
Emerg ency br
ency br aking
aking #
Press and hold handle 1.
As long as theve hicle is in motion, the
Release parking brake message is displayed
and there d! indicator lamp 0ashes.
When theve hicle has been braked toa stand-
still, the electric parking brake is applied. The
re d! indicator lamp lights up in the inst ru-
ment clus ter. Inf
Inf
or
ormation on collision det
mation on collision det ection on a park
ection on a park ed
ed
v
v ehicle
ehicle If a collision is de
tected when theto w- awa y pro-
te ction is primed on a loc kedve hicle, you will re
ceive a noti/cation in the multimedia system
when you switch theve hicle on.
Yo u will receive information about thefo llowing
points:
R The area of theve hicle that may ha vebeen
damaged.
R The forc e of the impact.
The following situation can lead toinadver tent
activation:
R The par kedve hicle is mo ved, forex ample, in a
two-s tore yga rage.
% Deactivate tow- awa y protection in order to
pr ev ent inadver tent activation. If you deacti-
va te to w-awa y protection, collision de tection
will also be deactivated.
Syst
Syst em limits em limits
De tection may be restric ted in thefo llowing situa-
tions:
R theve hicle is damaged without impact, for
ex ample, if an outside mir ror is torn o. or the
paint is damaged byakey
R an impact occurs at low speed R
the electric parking brake is not applied N No
ot
tes on par
es on par king up t
king up the v
he vehicle
ehicle If
yo u lea vetheve hicle par ked up for longer than
six weeks, it may su.er damage thro ugh disuse.
The 12 V battery may also be impaired or dam-
aged byheavy discharging.
V
V ehicles wit
ehicles wit h aut
h automatic tr
omatic tr ansmission:
ansmission: do not dis-
connect the 12 V battery even if theve hicle is leT
idle for a lengt hyperiod.
% Further information can be obtained at a
qu ali/ed specialist workshop. S
S
t
tandb
andb y mode (e
y mode (e xt
xtension of t
ension of t he st
he start
arter batt
er batt er
ery's
y's
per
per iod out of use)
iod out of use) S
S
t
tandb
andb y mode function
y mode function
% This function is not available for all models.
If standby mode is activated, energy loss will be
minimised during extended periods of non-opera-
tion. 218
218
Driving and parking