sensor MERCEDES-BENZ A-CLASS HATCHBACK 2021 Owners Manual

Fo
r fur ther information about there cycling and
disposal of end-of-life vehicles, and theta ke -back
conditions, please visit the national
Mercedes-Benz website foryo ur countr y. Mer
Mer
cedes-Benz GenuineP
cedes-Benz GenuineP ar
arts
ts
+ ENVIR
ENVIR ONMENT
ONMENT AL NO
AL NOTE
TEEnvironmental
damage caused bynot using recycled
re conditioned components Mercedes‑Benz
AGo.ers recycled recondi-
tioned components and parts with the same
qu ality as new parts. The same entitlement
from the implied warranty is valid as for new
parts. #
Recycled reconditioned components and
parts from Mercedes‑Benz AG. *
N
NO
OTE
TE Impai rment of the operating e1-
ciency of there straint systems from
installing accessor y parts or fromrepairs
or we lding Airbags and seat belt
tensioners, as well as
control units and sensors forth ere straint sys-
te ms, may be ins talled in thefo llowing areas
of your vehicle:
R Doors
R Door pillars
R Door sills
R Seats
R Cockpit
R Instrument clus ter
R Centre console
R Lateral roof frame #
Do not ins tall accessory parts such as
audio systems in these areas. #
Do not car ryout repairs or welding. #
Have accessory parts retro/tted at a
qu ali/ed specialist workshop. Yo
u could jeopardise the operating saf ety of your
ve hicle if you use parts, tyres and wheels as well
as accessories releva nt tosaf ety which ha venot
been app rove dby Mercedes-Benz. Saf ety-re leva nt
systems, e.g. the brake system, may malfunction.
Only use Mercedes-Benz GenuineParts or parts of
equal qualit y.Only use tyres, wheels and acces-
sory parts that ha vebeen speci/cally appr oved
fo ryo ur vehicle model.
Mercedes-Benz tests original pa rts and con ver-
sion parts and accessory parts that ha vebeen
speci/cally appr ovedfo ryo ur vehicle model for
th eir reliability, saf ety and suitability. Despite
ongoing mar ketre sear ch, Mercedes-Benz is
unable toassess other parts. Mercedes-Benz
th erefore accepts no responsibility forth e use of
such parts in Mercedes-Benz vehicles, even if
th ey have been o1cially appr oved or independ-
ently appr ovedby ate sting centre.
Ce rtain parts are only o1cial lyappr ovedfor
installation or modi/cation if they comply with
legal requ irements. All Mercedes-Benz Genuine-
Pa rts meet the appr oval requ irements. The use of
non-appr oved parts may in validate theve hicle's
ge neral ope rating permit. General no
tes
25 25

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

R
R
es
estr traint syst
aint syst em functionality
em functionality When
theve hicle is switched on, a self-test is per-
fo rm ed, during which the6 restraint system
wa rning lamp lights up. It goes out no later than a
few seconds aTer theve hicle is star ted. The com-
ponents of there straint system are then func-
tional. Malfunctioning r
Malfunctioning r
es
estr traint syst
aint syst em
em A malfunction has occur
red in there straint sys-
te m if:
R the6 restraint system warning lamp does
not light up when theve hicle is switched on
R the6 restraint system warning lamp lights
up continuously or repeatedly during a journey
All v
All v ehicles, ex
ehicles, excep
cep t plug-in h
t plug-in h ybr
ybrid:
id: &
W
WARNING
ARNING Risk of injury due tomalfunc-
tions in there straint system
Co mp onents in there straint system ma y be
acti vated unintentionally or not deploy as
intended in an accident. #
Have there straint system checked and
re paired immediately at a quali/ed spe-
cialist workshop. Plug-in h
Plug-in h
ybr
ybrid:
id: &
D
DAN
AN GER
GER Risk of fatal injuries due to
re straint system malfunctions
Co mp onents in there straint system ma y be
acti vated unintentionally or not deploy as plan-
ned in an accident. In theeve nt of an acci-
dent, the high-voltage on-board electrical sys-
te m may not be deactivated as intended.
Yo u may su.er an electric shock if youto uch
th e damaged components of the high-voltage
on-board electrical system. #
Have there straint system checked and
re paired immediately at a quali/ed spe-
cialist workshop. #
ATer an accident, switch o. theve hicle
immediatel y. F
F
unction of t
unction of t he r
he res
estrtraint syst
aint syst em in an accident
em in an accident How
there straint system works is de term ined by
th e se verity of the impact de tected and the type
of accident anticipated:
R Frontal impact
R Rear impact
R Side impact
R Only for cer tain countries: rollo ver
The activation thre sholds forth e components of
th ere straint system are de term ined based on the
ev aluation of the sensor values measured at vari-
ous points in theve hicle. This process is pre-e mp-
tive in nature. The triggering/deployment of the
components of there straint system must take
place in good time at the start of the collision.
Fa ctors which can only be seen and measured
aTer a collision has occur red do not play a deci-
sive role in the deployment of an airbag. Nor do
th ey prov ide an indication of airbag deployment.
The vehicle may be deformed signi/cantly without
an airbag being deplo yed. This is the case if only
parts which are relatively easily deformed are
a.ec tedand thera te of vehicle deceleration is Occupant saf
ety
47
47

&
W
WARNI NG
ARNI NGRisk of injury due tomalfunc-
tioning sensors in the door
The function of the airbags can be impaired
due tomodi/cations or incor rect wo rkper-
fo rm ed on the doors or door trim, or if the
doors are damaged. #
Never modify the doors or parts of the
doors. #
Always ha veworkon the doors or door
trim car ried out at a quali/ed specialist
wo rkshop. &
W
WARNING
ARNING Risk of injury due todeplo yed
airbag
A depl oyed airbag no longer o.ers any pr otec-
tion. #
Have theve hicle towe dto a quali/ed
specialist workshop in order tohave the
deplo yed airbag replaced. Ha
ve deplo yed airbags replaced immediatel y. S
S
t
tatus of t
atus of t he fr
he front passeng
ont passeng er fr
er front airbag
ont airbag F
F
unction of t
unction of t he aut
he automatic fr
omatic fr ont passeng
ont passeng er airbag
er airbag
shut
shut o.
o.
The automatic front passen ger airbag shuto. is
able todetect whe ther the front passenger seat is
occupied bya person or a child restraint system.
The front passenger airbag is enabled or disabled
acco rdingl y. &
W WARNI NG
ARNI NGRisk of injury or dea thdue to
objects under the co-driver seat
Objects trapped under the co-driver seat can
inter fere with the function of the automatic
co-driver airbag shuto. or damage the system. #
Do not store any objects under the co-
driver seat. #
When the co-driver seat is occupied,
make sure that no objects are trapped
under the co-driver seat. When /tting a
child restraint system tothe front
passenger seat, obser vetheve hicle-speci/c infor-
mation (/ page 77). Also, alw ays obser vethe
no tes on rear wa rd-facing or forw ard-facing child re
straint systems on the front passenger seat
(/ page 76).
A person on the front passenger seat must
obser vethefo llowing information:
R Fasten seat belts co rrectly (/ page 48).
R Sit in an almost upright seat position with their
back against the seat backrest.
R Sit with their feet resting on the 0oor, if possi-
ble.
The front passenger airbag may otherwise be dis-
abled bymistake, forex ample, in thefo llowing sit-
uations:
R The front passenger transfers their weight by
supporting themsel ves on a vehicle armrest.
R The front passen ger sits in such a wayth at
th eir weight is raised from the seat sur face. &
W
WARNING
ARNING Risk of injury or death due to a
disabled front passenger airbag
The front passenger airbag is disabled when
th ePA SSENGER AIR BAG OFF indicator la mp
is lit. 56 56
Occupant saf
ety

#
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

1
Closing
2 Toopen
The buttons on the driver's door take precedence. #
T
To st
o st ar
art aut
t aut omatic oper
omatic oper ation:
ation:presstheW
button be yond the point of resis tance or pull
and release it. #
T
To int
o int err
errup
upt aut
t aut omatic oper
omatic oper ation:
ation:press or pull
th eW button again. When
theve hicle is switched o., you can con-
tinue tooperate the side windo ws.
This function is available for around four minutes
or until a front door is opened.
A A ut ut omatic rev
omatic rever
ersing function of t
sing function of t he side windows
he side wind ows
If an obs tacle impedes a side window during the
closing process, the side window will open again
automaticall y.The automatic reve rsing function is
only an aid and is not a substitute foryo ur atten-
tiveness. #
During the closing process, make sure that no
body parts are in the closing area. &
W
WARNING
ARNING Risk of becoming trapped
despite there being reve rsing pr otection
on the side window
The reve rsing function does not react:
R tosoT, light and thin objects, e.g. /n gers.
R during resetting.
The reve rsing function cannot pr event some-
one from becoming trapped in these situa-
tions. #
During the closing process, make sure
th at no body parts are in the closing
area. #
If someone becomes trapped, press the
W button toopen the side window
again. A
A
ut
ut omatic function of t
omatic function of t he side windows
he side wind ows In
thefo llowing cases, the side windo wswill be
closed automatically when theve hicle is switched
o.:
R if it starts torain
Ra in is de tected byara in sensor on the wind-
screen.
R inextreme temp eratures
R aTer a cer tain time (depending on the on-
board electrical system voltage)
R ifth ere is a malfunction in the po wer supply
The side windo wswill be closed as far as theve n-
tilation position. Opening and closing
93
93

#
When closing thero ller sunblind, make sure
th at no body parts are in thera nge of mo ve-
ment. &
W
WARNING
ARNING Risk of becoming trapped
despite reve rsing function
In particular, there ve rsing function does not
re act tosoT, light and thin objects, e.g. /n-
ge rs. #
When closing thero ller sunblind, make
sure that no body parts are in thera nge
of mo vement. #
Release the button immediately if some-
body becomes trapped.
or #
Brie0y press the button in any direction
during the automatic closing process.
The closing process will be stopped. A
A
ut
ut omatic functions of t
omatic functions of t he sliding sunr
he sliding sunroof
oof%
The term "sliding sunroof" also refers to the
panorama sliding sunroof. The sliding sunroof will be closed automatically
when theve hicle has been switched o. in thefo l-
lowing situations:
R if it starts torain
Ra in is de tected byara in sensor on the wind-
screen.
R inextreme temp eratures
R aTer a cer tain time (depending on the on-
board electrical system voltage)
R ifth ere is a malfunction in the po wer supply
The sliding sunroof will rise at there ar in order to
continue ventilating theve hicle interior.
If th e sliding sunroof is obstructed during an auto-
matic closing procedure, thero of will be opened
again slightl y.The automatic function forth e slid-
ing sunroof and the side windo wswill then be
deactivated.
R
R ain-closing f ain-closing f eatur
eature when dr
e when dr iving
iving
V
V ehicles wit
ehicles wit h a panor
h a panorama sliding sunr
ama sliding sunr oof:
oof:if it
starts torain, thera ised sliding sunroof will auto-
matically be lo wered while theve hicle is in
motion. A
A
ut
ut omatic low
omatic low er
ering function
ing function
V
V ehicles wit
ehicles wit h a panor
h a panorama sliding sunr
ama sliding sunr oof:
oof:ifthe
sliding sunroof is raised at there ar, it will auto-
matically be lo wered slightly at higher speeds. At
low speeds, it will be raised again automaticall y. &
W
W ARNI NG
ARNI NGRisk of becoming trapped by
automatic lo wering of the sliding sunroof
At higher speeds, thera ised sliding sunroof
will automatically be lo wered slightly at the
re ar. #
Make sure that nobody reaches into the
sliding sunroof's range of mo vement
while theve hicle is in motion. #
If somebody becomes trapped, brie0y
push the sliding sunroof button forw ards
or backwards. %
By pushing or pulling the3 button, you
can inter rupt the automatic functions "Rain
closing function when driving" and "Automatic
lo we ring". 98 98
Opening and closing

Pr
Pr
iming/deactiv
iming/deactiv atingtow
ating tow-awa
-a wa y pr ot
y pr otection
ection Multimedia system:
4 © 5
Settings 5
Quick access #
Prime or deactivate Tow-away protection.
To w- awa y protection is primed again in thefo llo w-
ing cases:
R The vehicle is unloc ked again.
R A door is opened.
R The vehicle is loc ked again.
% Ifqu ick access is una vailable, select theVehi-
cle submenu in theSettings main menu to
prime or deactivate tow- awa y protection. F
F
unction of int
unction of int er
erior pr ot
ior pr otection
ection When interior pr
otection is primed, a visual and
audible alarm is triggered if mo vement is de tected
in theve hicle interior.
Interior pr otection is primed automatically aTer
appr oximately ten seconds:
R aTer locking theve hicle with thekey
R aTer locking theve hicle using KEYLESS-GO Interior pr
otection is only primed when thefo llo w-
ing components are closed:
R doors
R tailgate
Interior pr otection is automatically deactivated:
R aTer pressing theÜ button on thekey
R aTer pressing the start/s top button with the
ke y in the st owage compartment
(/ page 166)
R aTer unlocking theve hicle using KEYLESS-GO
The following situations can lead toafa lse alarm:
R when there are moving objects such as mas-
cots in theve hicle interior
R when a side wind owis open
R when a panoramic sliding sunroof is open Pr
Pr
iming/deactiv
iming/deactiv ating int
ating int er
erior pr ot
ior pr otection
ection Multimedia system:
4 © 5
Settings 5
Quick access #
Prime or deactivate Interior motion sensor .Interior pr
otection is primed again in thefo llowing
cases:
R The vehicle is unloc ked again.
R A door is opened.
R The vehicle is loc ked again.
% Ifqu ick access is una vailable, select theVehi-
cle menu under Settingstoprime or deacti-
va te interior pr otection. Opening and closing
101 101

A
A
dap
dap tiv
tive Highbeam Assist
e Highbeam Assist A
A
dap
dap tiv
tive Highbeam Assis
e Highbeam Assist function t function &
W
W ARNING
ARNING Risk of accident despite Adap-
tive Highbeam Assist
Ad aptive Highbeam Assist does not react to:
R road users without lights, e.g. pedestrians
R road users with poor lighting, e.g. cyclists
R road users whose lighting is obstructed,
e.g. bya bar rier
On very rare occasions, Adaptive Highbeam
Assist may failto recognise other road users
with their own lighting, or may recognise them
to o late.
In these, or in similar situations, the automatic
high beam will not be deactivated or will be
activated despite the presence of other road
users. #
Always obser vethero ad and tra1c con-
ditions carefully and switch o. the high
beam in good time. Ad
aptive Highbeam Assist cann ottake into
account road, weather or tra1c conditions.
De tection may be restric ted in thefo llowing
cases:
R In poor visibility, e.g. fog, heavy rain or snow
R Ifth ere is dirt on the sensors or the sensors
are obscured
Ad aptive Highbeam Assist is only an aid. You are
re sponsible for adjusting theve hicle's lighting to
th e pr evailing light, visibility and tra1c conditions. Ad
aptive Highbeam Assist automatically switches
between thefo llowing types of light:
R Low beam
R High beam
At speeds greater than 30 km/h:
R If no other road users are de tected, the high
beam will switch on automaticall y. Light and sight
139 139

The high beam will switch o. automatically in
the
fo llowing cases:
R Atspeeds below 25 km/h
R Ifot her road users are de tected
R If st reet lighting is su1cient
% The system's optical sensor is located behind
th e windscreen near theove rhead control
panel.
Switc
Switc hing A
hing A dap
daptiv
tive Highbeam Assis
e Highbeam Assist ton/o.
on/o.
Switc
Switc hing on
hing on #
Turn the light switch totheà position. #
Switch on the high beam using the combina-
tion switch.
If Ad aptive Highbeam Assist is activated,
th e_ indicator lamp will light up on the
cent ral display section of the inst rument dis-
pla y.
Switc Switc hing
hingo.
o. #
Switch o. the high beam using the combina-
tion switch. A
A
dap
dap tiv
tive Highbeam Assis
e Highbeam Assist Plus t Plus A
A
dap
dap tiv
tive Highbeam Assis
e Highbeam Assist Plus function t Plus function &
W
WARNING
ARNING Risk of accident despite Adap-
tive Highbeam Assist Plus
Ad aptive Highbeam Assist Plus does not react
to:
R road users without lights, e.g. pedestrians
R road users with poor lighting, e.g. cyclists
R road users whose lighting is obstructed,
e.g. bya bar rier
On very rare occasions, Adaptive Highbeam
Assist Plus may failto recognise other road
users with their own lighting, or may recognise
th em too late.
In these, or in similar situations, the automatic
high beam will not be deactivated or will be
activated despite the presence of other road
users. #
Always obser vethero ad and tra1c con-
ditions carefully and switch o. the high
beam in good time. Ad
aptive Highbeam Assist Plus cann ottake into
account road, weather or tra1c conditions.
De tection may be restric ted in thefo llowing
cases:
R in poor visibility, e.g. fog, heavy rain or snow
R ifth ere is dirt on the sensors or the sensors
are obscured
Ad aptive Highbeam Assist Plus is only an aid. Yo u
are responsible for adjusting theve hicle's lighting
to the pr evailing light, visibility and tra1c condi-
tions. 140 140
Light and sight