belt MERCEDES-BENZ A-CLASS HATCHBACK 2021 Service Manual

to
ne sounds in addition tothe visual warning mes-
sage.
If th e driver still does not respond tothewa rning,
th eBeginning emergency stop message appears
in the Instrument Displa y.Ifth e driver still does
not respond, Active Distance Assist DISTRONIC
re duces the speed. The vehicle is decelerated in
stages toa standstill.
Depending on the countr y,at speeds below
60 km/h the hazard warning lights switch on
automaticall y.
When theve hicle is stationar y,thefo llowing
actions are car ried out:
R The vehicle is secured with the electric par k-
ing brake.
R Active Distance Assist DISTRONIC is ended.
R The vehicle is unloc ked.
R If possible, an emer gency call is placed tothe
Mercedes-Benz eme rgency call centre.
The driver can cancel the deceleration at any time
by per form ing one of thefo llowing actions:
R Steering R
Braking or accelerating
R Deactivating Active Distance Assist
DISTRONIC A A
ctiv
ctiv e Br
e Br ak
ake Assist
e Assist F
F
unction of A
unction of A ctiv
ctive Br
e Br ak
ake Assist
e Assist
Ac tive Brake Assist consists of thefo llowing func-
tions:
R Distance warning function
R Autonomous braking function
R Situation-dependent braking assistance
R V
Vehicles wit
ehicles wit h Dr
h Driving Assist
iving Assist ance P
ance Pack
ackag
age:
e: Eva-
sive Steering Assist and cornering function
Ac tive Brake Assist can help youto minimise the
ri sk of a collision with vehicles, cyclists or pedes-
trians or toreduce the e.ects of such a collision.
If Ac tive Brake Assist has de tected a risk of colli-
sion, a warning tone sounds and theL dis-
ta nce warning lamp lights up in the inst rument
cluster. V V
ehicles wit ehicles wit h PRE-S
h PRE-SAFE
AFE®
®
:
:depending on the coun-
tr y, an additional haptic warning occurs in the
fo rm of slight, repeated tensioning of the seat
belt.
If yo u do not react tothewa rning, autonomous
braking can be initiated in critical situations.
In especially critical situations, Active Brake Assist
can initiate autonomous braking directl y.In this
case, thewa rning lamp and warning tone occur
simultaneously with the braking application.
If yo u apply the brake yourself in a critical situa-
tion or apply the brake during autonomous brak-
ing, situation-dependent braking assistance
occurs. The brake pressure increases up tomaxi-
mum full-s top braking if necessar y.
Obser vethe no tes on driving systems and your
re sponsibility; you may otherwise failto recognise
dangers (/ page 219). Driving and parking
241 241

If autonomous braking or situation-dependent
braking assis
tance has occur red, display 1
appears in the Instrument Display and then auto-
matically goes out aTer a short time.
If th e autonomous braking function or the situa-
tion-dependent braking assistance is triggered,
additional pr eventive measures for occupant pro-
te ction (PRE- SAFE®
) may also be initiated. &
W WARNING ARNING Risk of an accident caused by
limited de tection per form ance of Active
Brake Assist
Ac tive Brake Assist cannot alw ays clear lyiden-
tify objects and complex tra1c situations. In such cases,
Active Brake Assist might:
R Give a warning or brake without reason
R Not give a warning or not brake
Ac tive Brake Assist is only an aid. The driver is
re sponsible for maintaining a su1ciently safe
distance totheve hicle in front, vehicle speed
and for braking in good time. #
Always pay careful attention tothe tra1c
situation; do not relyonActive Brake
Assist alone. #
Be prepa redto brake or swer veif neces-
sar y. Also obser
vethe system limits of Active Brake
Assist.
The individual subfunctions ar The individual subfunctions ar eav
e av ailable in v
ailable in v ar
ari-
i-
ous speed r
ous speed r ang
anges:
es:
The dis tance warning function can issue a warn-
ing in thefo llowing situations:
R From appr oximately 30 km/h, if over se veral
seconds the distance maintained totheve hi-
cle tr avelling in front is insu1cient forthe driven speed,
theL distance warning lamp
lights up in the inst rument clus ter.
R From appr oximately 7 km/h, if your vehicle is
critically close toave hicle, cyclist or pedes-
trian, you will hear an intermittent warning
to ne and theL distance warning lamp
lights up in the inst rument clus ter.
V
V ehicles wit
ehicles wit h PRE-S
h PRE-SAFE
AFE®
®
:
:depending on the
count ry, an additional haptic warning occurs
in thefo rm of slight, repeated tensioning of
th e seat belt.
Brake immediately or take evasive action, pr ovi-
ded it is safe todo so and the tra1c situation
allo ws th is.
Dist
Dist ance w
ance w ar
arning function (v
ning function (v ehicles wit
ehicles wit hout Dr
hout Driv-
iv-
ing Assist
ing Assist ance P
ance Pack
ackag
age)
e)
The distance warning function can aid you in the
fo llowing situations with an intermittent warning
to ne and a warning lamp:
R at speeds up toappr oximately 250 km/h
when approaching vehicles ahead 242
242
Driving and parking

#
End the support byactively steering in
non-critical situations. #
Drive at an appropriate speed if there
are pedestrians close tothe path of your
ve hicle. Syst
Syst
em limits
em limits
Fu ll system per form ance is not yetav ailable for a
few seconds aTer switching on theve hicle or aTer
driving o..
If Ac tive Brake Assist is impaired or inoperative
due toa malfunction, theÄ warning lamp
appears in the Instrument Displa y.
The system may be impai red or may not function,
particular lyin thefo llowing situations:
R In sno w,rain, fog, heavy spr ay, if there is glare,
in direct sunlight or in greatly varying light
conditions.
R Ifth e sensors are dirty, misted up, damaged or
co vered.
R Ifth e sensors are impaired due tointer fere nce
from other radar sources, e.g. strong radar
re 0ections in multi-s tore y car par ks. R
If a loss of tyre pressure or a defecti vetyre
has been de tected and displa yed.
R In complex tra1c situations where objects
cannot alw ays be clear lyidenti/ed.
R If pedestrians or vehicles mo vequickly into
th e sensor de tection range.
R If pedestrians are hidden by other objects.
R Ifth e typical outline of a pedestrian cannot be
distinguished from the backg round.
R If a pedestrian is not de tected as such, e.g.
due tospecial clo thing or other objects.
R Ifth e driver's seat belt is not fastened.
R On bends wi tha tight radius.
% The Active Brake Assist sensors adjust auto-
matical lywhile a cer tain distance is being
driven aTer theve hicle has been deli vered.
Ac tive Brake Assist is una vailable or only par-
tially available during thete ach-in process.
A
A ctiv ctiv ating/deactiv
ating/deactiv ating A
ating Activ
ctive Br
e Br ak
ake Assist
e Assist
R
R eq
eq uir
uir ements:
ements:
R The vehicle is switched on. Multimedia system:
4 © 5
Settings 5
Assistance
5 Active Brake Assist #
Select the desired setting.
The setting is retained when the drive system
is next star ted.
Deactiv
Deactiv ating A
ating Activ
ctive Br
e Br ak
ake Assist
e Assist
% It is recommended that you alw ays lea ve
Ac tive Brake Assist acti vated. #
Select Off.
The distance warning function, the autono-
mous braking function and Evasive Steering
Assist are deactivated.
When theve hicle is next star ted, the middle
setting is automatically selected.
% IfAc tive Brake Assist is deactivated, theæ
symbol appears in the status bar of the Instru-
ment Displa y. Driving and parking
245 245

The MBUX Int
The MBUX Int
er
erior Assist
ior Assist ant suppor
ant suppor ts t
ts the f
he f ollo
ollowing int
wing int er
eractions:
actions: Int
Int
er
eraction ar
action ar ea
ea Int
Inter
eraction
action Descr
Descrip
iption
tion
In front of the media display or
abo vetheto uchpad Pr
ox imity tothe control element The Interior Assistant recognises the approach of the hand towa rds a cont rol
element.
Depending on the active application, the display will be adjusted in the media
displa y.Some functions di.e rentiate between driver and front passenger.
No speci/c hand position is requ ired.
Ab ove the centre console De/ned pose Afavo urite is called up with a de/ned pose.
Below the inside rearview mir rorB rief up and down mo vements With brief up and down mo vements below the inside rearview mir rorth ere ad-
ing light forth e driver or the front passenger is switched on or o..
Ab ove the front passenger seat Stretching out a hand abo vethe front
passenger seat By str
etch ing out a hand abo vethe front passenger seat the sear chlight is
switched on. If you withdr awa hand from this area, the sear chlight is
switched o. again. Switc Switc
hing t
hing t he r
he reading light and searc
eading light and searc h light and
h light and
on or
on or o.
o. R
R
eq
eq uir
uir ements:
ements:
R F
For t
or t he r
he r eading light
eading light: :
- The function is available when it is dar k.-
The hand mo vement take s place in the
interaction area below the inside rearview
mir ror.
R F
For t
or t he searc
he searc h light
h light::
- The function is available when it is dar k.-
The hand mo vement take s place in the
interaction area abo vethe front passenger
seat.
- The seat belt on the front passenger seat
must no not
tbe inser ted in the seat belt
buckle. MBUX multimedia system
291
291

The Mercedes‑Benz eme
rgency call system trig-
ge rs an emer gency call automatically in thefo l-
lowing cases:
R ATer activation of there straint systems su ch
as airbags or seat belt tensioners aTer an
accident
The eme rgency call has been made:
R Avo ice connection is made tothe
Mercedes‑Benz eme rgency call centre.
R A message with accident data is transmitted
tothe Mercedes‑Benz emer gency call centre.
The Mercedes‑Benz eme rgency call centre
can transmit theve hicle position data toone
of the public emer gency services call centres.
R Under cer tain circumstances data is also
transmitted in thevo ice channel tothe
Mercedes‑Benz eme rgency call centre.
This allo wsmeasures forre scue, reco very or
to wing toa Mercedes‑Benz Se rvice Centre to
be initiated quickl y.
The SOS button in theove rhead control panel
0ashes until the emer gency call is /nished. It is not possible
toimmediately end an automatic
emer gency call.
If th e Mercedes‑Benz emer gency call system can-
not connect tothe Mercedes‑Benz emer gency
call centre, the emer gency call is automatically
sent tothe public emer gency services call centre.
If no connection can be made tothe public emer-
ge ncy services, a cor responding message
appears in the displa y. #
Dial the emer gency number 112 112onyour
mobile phone.
If an emer gency call has been initia ted:
R Remain in theve hicle if thero ad and tra1c
conditions permit youto do so until a voice
connection is established with the emer gency
call centre ope rator.
R Based on the call, the operator decides
whe ther it is necessary tocall rescue teams
and/or the police tothe accident site.
R If no vehicle occupant answers, an ambulance
is sent totheve hicle immediatel y. T T
r
r igg
igg er
ering a manual Mer
ing a manual Mer cedes-Benz emerg
cedes-Benz emerg ency
ency
call
call #
T
To use t
o use t he SOS butt
he SOS butt on in t
on in theov
he overerhead con-
head con-
tr
tr ol panel:
ol panel: press and hold the SOS button for
at least one second (/ page 311). #
T
To use v
o use v oice contr
oice contr ol:
ol:use the LINGU ATRO NIC
vo ice commands .
The emer gency call has been made:
R Avo ice connection is made tothe Mercedes-
Benz emer gency call centre.
R A messa gewith accident data is transmit ted
to the Mercedes-Benz emer gency call centre.
The Mercedes-Benz eme rgency call centre
can transmit theve hicle position data toone
of the public emer gency services call centres.
R Under cer tain circumstances data is also
transmitted in thevo ice channel tothe
Mercedes-Benz eme rgency call centre.
This allo wsmeasures forre scue, reco very or
to wing toa Mercedes-Benz Se rvice Centre to
be initiated quickl y.
R Remain in theve hicle if thero ad and tra1c
conditions permit youto do so until a voice MBUX multimedia system
321
321

Ext
Ext
er
erior lighting
ior lighting
R Clean the lenses with a wet sponge and mild
cleaning agent, e.g. car sha mpoo.
R Only use cleaning agents or cleaning clo ths
th at are suitable for plastic lenses.
V
V ehicle soc ke
ehicle soc ket (high-v
t (high-v olt
oltag
age batt
e batt er
ery)
y)
R Use clean water and a soT clo thtoclean the
ve hicle soc ket.
R Do not use high-pressure cleaners or cleaning
agents, such as soap.
Sensors
Sensors
R Clean the sensors in the front and rear bump-
ers with a soT clo thand car shampoo
(/ page 220).
R When using a high-pressure cleaner, main tain
a minimum distance of 30 cm.
Rev Rev er
ersing camer
sing camer a and 360° Camera
a and 360° Camera
R Open the camera co ver with the multimedia
system (/ page 260).
R Use clean water and a soT clo thtoclean the
camera lens.
R Do not use a high-pressure cleane r.T
T
ailpipes
ailpipes
R Clean with a cleaning agent recommended for
Mercedes-Benz, especially in the winter and
aTer washing theve hicle.
R Do not use acidic cleaning agents.
Tr
Tr ailer hitch
ailer hitch
R Obser vethe no tes on care in the trailer hitch
manufacturer's operator manual.
R Do not clean the ball neck with a high-pres-
sure cleaner or sol vent.
R Remo vetraces of rust on the ball, forex ample,
with a wire brush.
R Remo vedirt with a lint-free clo th.
R ATer cleaning, lightly oil or grease the ball
head.
% Before using trailers with anti-torsional cou-
pling, obser vethe manufacturer's operator
manual. N No
ot
tes on car
es on car e of t
e of t he int
he int er
erior
ior &
W
WARNING
ARNING Risk of injury from plastic parts
breaking o. aTer the use of sol vent-based
ca re products
Care and cleaning products containing sol-
ve nts can cause sur faces in the cockpit to
become porous. When the airbags are
deplo yed, plastic parts may break away. #
Do not use any care or cleaning products
containing sol vents toclean the cockpit. &
W WARNING
ARNING Risk of injury or fatal injuries
from bleached seat belts
Bleaching or dyeing seat belts can se verely
we aken them.
This can, forex ample, cause seat belts to tear
or fail in an accident. #
Never bleach or dye seat belts. To
avo id damage totheve hicle, obser vethefo l-
lowing no tes on cleaning and care: Main
tenance and ca re
343
343

Seat belts
Seat belts
R Clean wi thluk ewa rmand soapy water.
R Do not use chemical cleaning agents.
R Do not dry byheating them toove r 80°C or
ex posing them todirect sunlight.
Display
Display
R Switch o. the display and let it cool down.
R Clean the sur face carefully with a micro/bre
clo thand a suitable displ aycare product (TFT-
LC D).
R Do not use any other agents.
Head-up displ ay
Head-up display
R Clean with a soT, non-static, lint-free clo th.
R Do not use cleaning agents.
Plas
Plastic tr tic tr im
im
R Clean with a damp micro/bre clo th.
R For heavy soiling: Use a cleaner recommen-
ded for Mercedes-Benz.
R Do not attach stic kers, /lms or similar materi-
als. R
Do not allow cosmetics, insect repellent or
sun cream tocome in contact with the plastic
trim.
R
R eal w
eal w ood and tr
ood and tr im elements
im elements
R Clean with a micro/bre clo th.
R Blackpiano-lacquer look: Clean with a damp
clo thand soapy water.
R For heavy soiling: Use a cleaner recommen-
ded for Mercedes-Benz.
R Do not use sol vent-based cleaning agents, pol-
ishes or waxes.
R
R oof lining
oof lining
R Clean with a brush or dry shampoo.
Car
Car pet
pet
R Use a carpet and textile cleaning agent recom-
mended for Mercedes-Benz.
St
St eer
eer ing wheel made of g
ing wheel made of g enuine leat
enuine leather or DINA-
her or DINA-
MICA
MICA
* NO
NOTE
TEDamage caused bywrong cleaners #
Do not use sol vent-based cleaning
agents such as tarre mo ver or wheel cleaner; neither should
you use polishes
or wa xes. Otherwise you may damage
th e /nish. R
Clean with a damp clo thand 1% soapy water
solution and then wipe with a dry clo th.
R For heavy soiling: Use a cleaner recommen-
ded for Mercedes-Benz.
R Leather care: Use a leather care agent that
has been recommended for Mercedes-Benz.
R Do not allow the leather tobecome too damp.
R Do not use a micro/bre clo th.
% Leather is a natural product. It has natural
surface properties, such as di.erences in
st ru cture, mar kscaused bygrow thand injury
or subtle colour di.erences. These sur face
properties are characteristics of leather and
not material faults. What's more, leather is
subject toa natural ageing process during
which the sur face properties change.
Genuine leat
Genuine leat her seat cov
her seat cov ers ers
R Clean with a damp clo thand then wipe with a
dry clo th. 344
344
Maintenance and care

W
W
ar
ar ning and indicat
ning and indicat or lam
or lamps
ps Ov
Ov
er
ervie
vie w of indicat
w of indicat or and w
or and war
arning lam
ning lam ps
ps Some systems will per
form a self-test when the
ve hicle is switched on. Some indicator and warn-
ing lamps may brie0y light up or 0ash. This beha v-
iour is non-critical. These indicator and warning
lamps indicate a malfunction only if they light up
or 0as haTer theve hicle has been star ted or dur-
ing a journe y.
S
S t
tandar
andar d ins
d instr
trument displ ay
ument display W
W
idescr
idescr een coc
een coc kpit ins
kpit instrtrument display
ument display Depending on
the display setting, the positions of
th e indicator lamps on the inst rument display may
di.er from theex ample shown.
Indicat
Indicat or and w
or and w ar
arning lam
ning lam ps:
ps:
6 Restraint system (/ page 477)
ü Seat belt (/ page 477)
_ Reduced po wer (/ page 479)
Ú System error (/ page 479)
# Electricalfault (/ page 479)
ï Trailer hitch (/ page 480)
Ù Powe r steering (/ page 480) ÿ
V
V ehicles wit
ehicles wit h a widescr
h a widescr een coc
een coc kpit
kpit:
:
coolant temp erature (/ page 481)
; Engine diagnostics (/ page 481)
% V
Vehicles wit
ehicles wit h a diesel engine:
h a diesel engine: preglow
# Electricalfault (/ page 481)
æ Reser vefuel wi thfuel /ller 0ap loca-
tion indicator (/ page 481)
! Electric parking brake (red)
(/page 485)
! Electric parking brake (yellow)
(/page 485)
J Brakes (yellow) (/ page 485)
J Brakes (red) (/ page 485)
L Distancewarning (/ page 487)
Ó Active Brake Assist (/ page 487)
ê Active Brake Assist (/ page 487)
! ABS (/page 488)
÷ ESP®
(/ page 488)
å ESP®
OFF (/ page 488) 476 476
Display messages and
warning/indicator lamps

W
W
ar
ar ning/indicat
ning/indicat or lampP
or lam pP ossible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions &
D
DAN
AN GER
GER Risk of fatal injuries due torestraint system malfunctions
Co mp onents in there straint system ma y be activated unintentionally or not deploy as planned in an accident. In the
eve nt of an accident, the high-voltage on-board electrical system may not be deactivated as intended.
Yo u may su.er an electric shock if youto uch the damaged components of the high-voltage on-board electrical sys-
te m. #
Have there straint system checked and repaired immediately at a quali/ed specialist workshop. #
ATer an accident, switch o. theve hicle immediatel y. #
Drive on carefull y. #
Notethe messages on the instrument displa y. #
Consult a quali/ed specialist workshop immediatel y.
ü
Seat belt warning lamp
0ashes *T
he red seat belt warning lamp 0ashes and an intermittent warning tone sounds.
The driver or front passenger has not fastened his/her seat belt while theve hicle is in motion. #
Fasten your seat belt (/ page 51).
There are objects on the front passenger seat. #
Remo vethe objects from the front passenger seat. 478
478
Display messages and
warning/indicator lamps

W
W
ar
ar ning/indicat
ning/indicat or lampP
or lam pP ossible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions
ü
Seat belt warning lamp
lights up *T
he red seat belt warning lamp lights up once theve hicle has star ted.
In addition, an intermittent warning tone may sound.
The red seat belt warning lamp reminds the driver and front passenger tofasten their seat belts. #
Fasten your seat belt (/ page 51).
If yo u ha veplaced objects on the front passenger seat, there d seat belt warning lamp may remain lit. Hybr
Hybr
id syst
id syst em
em W
W
ar
ar ning/indicat
ning/indicat or lampP
or lam pP ossible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions
_
Re duced warning lamp
po wer *T
heyellow reduced-po werwa rning lamp is on.
Drive system po wer output is reduced. #
Notethe messages on the instrument displa y.
Ú
System er rorwa rning lamp *T
he red system er rorwa rning lamp is lit while theve hicle is in a state of operational readiness õ.
There is a malfunction in the drive system. #
Notethe messages on the instrument displa y. Display messages and
warning/indicator lamps
479
479