2021 MERCEDES-BENZ A-CLASS HATCHBACK brake sensor

when
Parking Assist PARKTRONIC sounds a warn-
ing tone. #
Select Audio fadeout during warning tones .#
Switch the function on or o.. A
A
ctiv
ctiv e P
e P ar
ar king Assist
king Assist F
F
unction of A
unction of A ctiv
ctive P
e Par
arking Assist
king Assist
Ac tive Parking Assist is an electronic parking
assistance system, which uses ultrasound with
th e assistance of there ve rsing camera and 360°
Camera. When you are driving forw ards up to
appr oximately 35 km/h, the system automatically
measures parking spaces on bo thsides of the
ve hicle.
Ac tive Parking Assist o.ers thefo llowing func-
tions:
R Country
Country -dependent
-dependent: :parking in parking spaces
parallel tothero ad
R Parking in parking spaces perpendicular tothe
ro ad (optionally either forw ards or reve rse)
R Exiting parking spaces if you ha vepar ked
using Active Parking Assist As soon as all
requ irements are met for sear ching
fo r parking spaces, theÇ display appears in
th e Instrument Displa y.
When Active Parking Assist has de tected parking
spaces, theÈ display appears in the Instru-
ment Displa y.The ar rows show on which side of
th ero ad de tected parking spaces are located.
They are then shown in the media displa y.
The parking space can be selected as desired.
Depending on the location of the parking space,
th e parking direction (rear wards or forw ards) can
also be selected as desired.
When Active Parking Assist is activated, the turn
signal indicators are activated based on the calcu-
lated path of your vehicle.
When you are entering or exiting a parking space,
th e procedure is assisted byacceleration, braking,
steering and gear changes.
V V ehicles wit
ehicles wit h manual tr
h manual tr ansmission:
ansmission: the active
brake application and automatic gear change are
only available on vehicles with automatic trans-
mission. You must therefore brake theve hicle and
ch ange gear yourself when parking or exiting a
parking space. Ac
tive Parking Assist is only an aid. It is not a sub-
stitute foryo ur attention tothe sur roundings. The
re sponsibility for safe manoeuvring and parking
re mains with you. Make sure that no persons, ani-
mals or objects etc. are in the manoeuvring
ra nge.
Ac tive Parking Assist will be cancelled in thefo l-
lowing situations:
R Parking Assist PARKTRONIC is deactivated.
R You begin steering.
R You apply the parking brake.
R V
V ehicles wit
ehicles wit h aut
h automatic tr
omatic tr ansmission:
ansmission: you
engage transmission position j.
R ESP ®
inter venes.
R You open the doors or theta ilgate while driv-
ing.
Syst
Syst em limits
em limits
If th eex terior lighting is malfunctioning, Active
Pa rking Assist is not available.
Objects located abo veor below the de tection
ra nge of the sensors, e.g. overhanging loads,
ov erhangs or loading ramp s of goods vehicles, or
th e borders of parking spaces, are not de tected Driving and parking
265
265

R
If an incor rect transmission position is
engaged.
Drive Away Assist is active under thefo llowing
conditions:
R IfPa rking Assist PARKTRONIC is activated.
R Ifyo u shiT the transmission position tok or
h when theve hicle is stationar y.
R Ifth e de tected obs tacle is less than appr ox.
1.0 m away.
R Ifth e manoeuvring assistance function is acti-
va ted in the multimedia system.
Syst
Syst em limits
em limits
The per form ance of Drive AwayAssist is limited
on inclines.
When driving with a trailer, Drive AwayAssist is
not available.
% Also obser vethe system limits of Parking
Assist PARKTRONIC (/ page 261).
F
F unction of Cr unction of Cr oss
ossTr
Tra1c
a1c Alert
Alert
% Cross Tra1c Ale rtis only available forve hicles
with Blind Spot Assist or Active Blind Spot
Assist. Cross
Tra1c Ale rtcan warndrivers of any cross-
ing tra1c when reve rsing and manoeuvring out of
a parking space. The radar sensors in the bumper
also monitor the area adjacent totheve hicle. If a
critical situation is de tected, theL symbol
appears in the media display and theve hicle can
be braked automaticall y.
If th era dar sensors are obstructed byvehicles or
ot her objects, de tection is not possible.
Cross Tra1c Ale rtis active under thefo llowing
conditions:
R ifth eve hicle is reve rsing at a walking pace.
R manoeuvring assista nce is activated
(/ page 270).
% Also obser vethe inst ructions on Blind Spot
Assist and Active Blind Spot Assist
(/ page 249).
Syst
Syst em limits
em limits
Cross Tra1c Ale rtis not available on inclines.
Cross Tra1c Ale rtis not available when driving
with a trailer. A
A
ctiv
ctiv ating/deactiv
ating/deactiv ating manoeuvr
ating manoeuvr ing assist
ing assistant
ant
Multimedia system:
4 © 5
Settings 5
Assistance
5 Camera & parking #
Activate/deactivate Manoeuvring assistance.
% Manoeuvring assistant must be acti veforthe
function of Drive AwayAssist (/ page 269)
and Cross Tra1c Ale rt (/ page 270). T
T
r
railer hitch
ailer hitch N
No
ot
tes on tr
es on tr ailer oper
ailer oper ation
ation *
N
NOOTE
TE Mercedes-AMG vehicles #
Obser vethe no tes in the Supplement.
Yo u could otherwise failto recognise
dangers. Obser
vethefo llowing no tes on theto ngue weight:
R Do not use a tongue weight that exceeds or
fa lls below the permissible tongue weight
R Use a tongue weight as close as possible to
th e maximum tongue weight 270
270
Driving and parking

*
N
NO
OTE
TE Damage from automatic braking If one of
thefo llowing functions is switched
on, theve hicle brakes automatically in cer tain
situations:
R Active Brake Assist
R Active Distance Assist DISTRONIC
R HOLD function
R Active Parking Assist
To avoid damage totheve hicle, deactivate
th ese systems in thefo llowing or similar situa-
tions: #
during towing #
in a car wash *
N
NOOTE
TE Damage due tounsuitable car wash #
Before driving into a car wash make sure
th at the car wash is suitable forth eve hi-
cle dimensions. #
Ensu rethere is su1cient ground clear-
ance between the underbody and the
guide rails of the car wash. #
Ensure that the clearance width of the
car wash, in particular the width of the
guide rails, is su1cient. To
avo id damage toyour vehicle when using a car
wa sh, ensu rethefo llowing beforehand:
R Active Distance Assist DISTRONIC is deactiva-
te d.
R The HOLD function is switched o..
R The 360° Camera or there ve rsing camera is
switched o..
R The side windo wsand sliding sunroof are com-
ple tely closed.
R The blo werfo rth eve ntilation/heating is
switched o..
R The windsc reen wiper switch is in position g.
R The key is at a minimum dis tance of 3 m away
from theve hicle. Otherwise theta ilgate could
open unintentionall y. R
In automatic car washes with con veyo r sys-
te ms:
- Neutral iis engaged.
- V
V ehicles wit
ehicles wit h aut
h automatic tr
omatic tr ansmission:
ansmission: If
yo uwo uld like tolea vetheve hicle while it
is being washed, make sure theke y is
located in theve hicle. The park position
j isotherwise automatically engaged.
% If, aTer the car wash, youre mo vethewax
from the windscreen and wiper rubbers, this
will pr event smearing and reduce wiper noise.
A
A ut
ut omatic car w
omatic car w ash mode
ash mode
In car wash mode, theve hicle is prepared for driv-
ing into the automatic car wash. Car wash mode
can be activated at a speed of up to20 km/h
Ac tivate (/ page 339).
The following settings are made when car wash
mode is activated:
R The outside mir rors are folded in.
R Topreve ntthe windscreen washer system
from starting up automaticall y,thera in sensor
is deactivated.
R The rear wind owwiper is deacti vated. 338
338
Maintenance and care

R
Furthermore, the use of cer tain tyre types in
cer tain regions and areas of operation can be
high lybene/cial.
R Only use tyres and wheels of the same type
(summer tyres, winter tyres, MOExtended
tyres) and the same make.
R Only /t wheels of the same size on one axle
(leT and right).
It is only permissible to/t a di.e rent wheel
size in theev ent of a 0at tyre in order todrive
to the specialist workshop.
R Do not make any modi/cations tothe brake
system, the wheels or the tyres.
The use of shims or brake dust shields is not
permitted and may in validate theve hicle's
ge neral ope rating permit.
R V
V ehicles wit
ehicles wit h a tyr h a tyre pr
e pressur
essur e monit
e monit or
or ing sy
ing sy s-
s-
t
t em:
em: all /t tedwheels must be equipped with
functioning sensors forth e tyre pressure mon-
itoring system.
R Attemp eratures below 7 °C use winter tyres
or all-season tyres mar kedi M+Sfor all
wheels. Wi
nter tyres pr ovide the best possible grip in
wintry road conditions.
R For M+S tyres, only use tyres with the same
tread.
R Obser vethe maximum permissible speed for
th e M+S tyres /t ted.
If th e tyre's maximum speed is below that of
th eve hicle, this must be indicated byan
appropriate label in the driver's /eld of vision.
R Run in new tyres at moderate speeds forthe
/r st 100 km.
R Replace the tyres aTer six years at the latest,
re ga rdless of wear.
R When r
When r eplacing wit
eplacing wit h tyr
h tyres t
es that do no
hat do no t f
t featur
eatur e
e
r
r un-0at
un-0at c
char
har act
act er
er is
istics:
tics: vehicles with
MOExtended tyres are not equipped with a
TIREFIT kit at thefa ctor y.Equip theve hicle
with a TIREFIT kit aTer replacing with tyres
th at do not feature run-0at characteristics,
e.g. winter tyres.
% You can permanently limit the maximum
speed for driving with winter tyres
(/ page 232). Fo
r more information on wheels and tyres, con-
ta ct a quali/ed specialist workshop.
Be sure toalso obser vethefo llowing fur ther rela-
te d subjects:
R Notes on tyre pressure (/ page 369)
R Tyre pressure table (/ page 370)
R Notes on the emer gency spa rewheel
(/ page 383) N
No
ot
tes on int
es on int erc
erchanging wheels
hanging wheels &
W
WARNING
ARNING Risk of injury thro ugh di.erent
wheel sizes
Inter changing the front and rear wheels can
se verely impair the driving characteristics.
The disk brakes or wheel suspension compo-
nents may also be damaged. #
Only inter change the front and rear
wheels if the wheels and tyres ha vethe
same dimensions. 376
376
Wheels and tyres

Displa
Displa
y messag
y messag es P
es Possible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions
¸
Ã
ç
Ä
temporarily unavailable
Sensors dirty *F
ront and corner radar sensors (hereaTer "sensors") are malfunctioning. Possible causes:
R The senso rsare dirty
R Heavy rain or snow
R Extended country driving without other tra1c, e.g. in the desert
Driving systems and driving saf ety sy stems ma y be malfunctioning or temp orarily una vailable. The brake system, steer-
ing and drive system will continue tofunction normall y. #
Drive on
Once the causes of the problem are no longer present, the driving systems and driving saf ety sy stems will be available
again and the cor responding symbols will be switched o..
If th e display message does not disappear: #
Stop theve hicle in accordance with the tra1c conditions. #
Clean all sensor co vers from outside (/ page 220). #
Restart theve hicle. 456 456
Displ
aymessages and warning/indicator lamps

Dr
Dr
iving syst
iving syst ems
ems W
W
ar
ar ning/indicat
ning/indicat or lampP
or lam pP ossible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions
L
Wa rning lamp for distance
wa rning function *T
he red distance warning lamp lights up while theve hicle is in motion.
The dis tance totheve hicle in front is too small forth e speed selected.
If th ere is an additional warning tone, you are approaching an obstacle at too high a speed. #
Be prepared tobrake immediatel y. #
Increase the distance.
Fu nction of Active Brake Assist (/ page 241).
Ó Ac tive Brake Assist warning
lamp *T
heActive Brake Assist warning lamp is on.
Due todirty sensors or a malfunction, the system is not available or thera nge of functions is restric ted. #
Notethe messages on the instrument displa y.
ê
Ac tive Brake Assist warning
lamp *T
heActive Brake Assist warning lamp is on.
The system is switched o. or thera nge of functions has been automatically restric ted.
This may be the case if the driver is not wearing a seat belt or ano ther driving system has been activated. #
Obser vethe no tes on Active Brake Assist (/ page 241). Display messages and
warning/indicator lamps
487
487

Br
Br
ak
ak es
es
ABS (Anti-lo ckBraking System).............. 221
Ac tive Brake Assist................................. 241
Ad aptive brake lights.............................. 226
BAS (Brake Assist System).................... .222
Driving tips............................................ 169
EBD (Electronic Brake forc e Distribu-
tion).......................................................2 24
HOLD function....................................... 225
Limited braking e.ect (salt-treated
ro ads)................................................... .169
Ne w/replaced brake linings/brake
discs...................................................... 168
Po st-collision brak e.................................. 61
Ru nning-in no tes.................................... 168
Br
Br ak ak es
es
see Recuperation
Br Br aking assist aking assist ance
ance
see BAS (Brake Assist System)
Br
Br eakdo
eakdo wn
wn
Assistance overview. ................................ 20
To w- starting........................................... 364
To wing away.......................................... 360
Tr anspo rting theve hicle........................ .362
Wheel chang e........................................ 378 Br
Br ea kdo
eakdo wn
wn
see Flat tyre
Butt
Butt ons
ons
St eering wheel....................................... 279 C
C
Calls
Calls Mercedes me......................................... 311
Camera
Camera
Information............................................ 220
Camera
Camera
see 360° Camera
see Dashcam
see Reversing camera
Car key
Car key
see Key
Car w Car w ash
ash
see Care
Car w
Car w ash (car
ash (car e)
e)............................................ 337
Car
Car -t
-to-X
o-X -Communication
-Communication
Displaying hazard warnings.................... 305
Care
Care 360° camera......................................... 342 Air-water duct........................................ 337
Au
tomatic car wash.............................. .337
Carpet................................................... 343
Decorative foil........................................ 341
Display................................................... 343
Exterior lighting...................................... 342
Head-up display..................................... 343
High-pressure cleaner............................3 39
Pa int...................................................... 340
Plastic trim............................................3 43
Re alwo od/trim elements..................... .343
Re versing camera..................................3 42
Ro of lining............................................. 343
Seat belt................................................ 343
Seat co ver............................................. 343
Sensors................................................. 342
St eering wheel....................................... 343
Ta ilpipes................................................ 342
Tr ailer hitc h............................................ 342
Ve hicle soc ketfo rth e high-voltage
battery................................................... 342
Wa shing byhand.................................... 340
Wheels/rims.......................................... 342
Wi ndo ws................................................ 342
Wi per blades.......................................... 342 496 496
Index

ç
suspended .................................... 449
: Switch o. lights............................ 418
: Switch on headlamps .................... 418
6 Tank is dep ressurised Ready for
re fuelling ............................................... 428
6 Tank ventilation Malfunction
Consult workshop ................................. .428
á temp orarily una vailable Camera
view restric ted....................................... 457
¸ temp orarily una vailable Sensors
dirty....................................................... 456
Ú Top up AdBlue Emer gency op. in
XXX miles See Owner's Manual.............. 471
+ Top up coolant See Owner ’s
Manual.................................................. 435
¥ Top up washer 0uid...................... .434
u Towing not permitted See Own-
er's Manual ............................................ 423
d Trans. oil overheated Drive on
with care................................................ 440 !
Turn on the ignition torelease
th e parking brake ................................... 446
Ú .................................................... 471
d Vehicle is operational Switch o.
ignition before exiting............................. 429
h Warning tyre defect....................... 468
h Wheel sensor(s) missing ................ 467
Ú XX,X l Top up AdBlue Swit chon
ignition, wait 60 sec. or eng. start not
poss...................................................... 472
"Electric" drive prog ram cur rently
una vailable............................................. 425
Ac tive Blind Spot Assist cur rently
una vailable See Owner's Manual ............ 454
Ac tive Blind Spot Assist inoperative........ 454
Ac tive Blind Spot Assist not available
when towing a trailer See Owner's
Manual.................................................. 455
Ac tive bonnet malfunction See Own-
er's Manual............................................ 432 Ac
tive Brake Assist Functions cur-
re ntly limi ted See Owner's Manual .........462
Ac tive Brake Assist Functions limited
See Owner's Manual.............................. 463
Ac tive Distance Assist available again ..... 451
Ac tive Distance Assist cur rently
una vailable See Owner's Manual ............ 450
Ac tive Distance Assist inoperative.......... 450
Ac tive Lane Keeping Assist cur rently
una vailable See Owner's Manual ............ 455
Ac tive Lane Keeping Assist inoperative... 455
Ac tive Steering Assist cur rently
una vailable due tomultiple emer-
ge ncy stops........................................... 452
Ac tive Steering Assist cur rently
una vailable See Owner's Manual ............ 452
Ac tive Steering Assist inoperative...........4 52
Ad aptive Highbeam Assist cur rently
una vailable See Owner's Manual ............ 418
Ad aptive Highbeam Assist inoperative ....4 19 502 502
Index