2021 MERCEDES-BENZ A-CLASS HATCHBACK engine

W
W
ar
ar ning/indicat
ning/indicat or lampP
or lam pP ossible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions
ï
Tr ailer tow hitch warning
lamp *T
hered trailer hitch warning lamp is lit.
The trailer hitch is not operational. &
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. #
Notethe messages on the instrument displa y.Engine
Engine
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ar
ar ning/indicat
ning/indicat or lampP
or lam pP ossible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions
ÿ
Coolant warning lamp (red) *T
he red coolant warning lamp is lit while the engine is running.
Po ssible causes:
R The temp erature sensor is malfunctioning
R The coolant le vel is too low
R The air supply tothera diator is obstructed
R The radiator fan is faulty Display message
s andwarning/indicator lamps
481
481

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ar
ar ning/indicat
ning/indicat or lampP
or lam pP ossible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions
R The engine coolant pump is faulty
If th ere is an additional warning tone, the coolant temp erature has exceeded 120°C. &
W
WARNING
ARNING Risk of burns when opening the bonnet
If yo u open the bonnet in theeve nt of an overheated engine or /re in the engine compartment, thefo llowing situa-
tions may occur:
R You may come into contact with hot gases.
R You may come into contact with other escaping hot operating 0uids. #
Before opening the bonnet, allow the engine tocool down. #
Intheev ent of a /re in the engine compartment, keep the bonnet closed and call the /re service. #
Stop immediately in accordance with the tra1c conditions and switch o. theve hicle. Do not continue driving. #
Notethe messages on the instrument displa y.
If t If t he coolant t
he coolant t em
emper
per atur
atur e displa
e displa y is at t
y is at the low
he lower end of t
er end of t he t
he tem
emper
per atur
atur e scale:
e scale: #
Consult a quali/ed specialist workshop.
If t
If t he coolant t he coolant t em
emper
per atur
atur e displa
e displa y is at t
y is at the upper end of t
he upper end of t he t
he tem
emper
per atur
atur e scale:
e scale: #
Exit theve hicle and keep a safe distance from it until the engine has cooled down. #
Check the coolant le vel (/ page 336). 482
482
Display message
s andwarning/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 #
Make sure that the air supply tothera diator is not obstructed. #
Avoiding high loads on the engine, drive tothe nearest quali/ed specialist workshop. In doing so, ensu rethat the
coolant temp erature display remains below 120°C.
ÿ
Coolant warning lamp (yel-
low) *T
he yellow coolant warning lamp is lit while the engine is running.
Po ssible causes:
R The temp erature sensor is malfunctioning
R The charge air, transmission oil or battery cooling is faulty
R The radiator shutters are bloc ked or defective #
Avoiding high loads on the engine, drive tothe nearest quali/ed specialist workshop.
; Engine diagnosis warning
lamp *T
he yellow engine diagnostics warning lamp is lit while the engine is running.
A malfunction has occur red in the engine, theex haust system or the fuel system.
The emissions limit value may ha vebeen exceeded and the engine may be running in eme rgency operation mode. #
Have theve hicle checked as soon as possible at a quali/ed specialist workshop.
V
V ehicles wit
ehicles wit h a diesel engine:
h a diesel engine: the fuel tank may ha vebeen run dr y. #
Start the engine thre eto four times aTer refuelling.
If th eye llow engine diagnosis warning lamp goes out, emer gency ope ration mode is cancelled. The vehicle need not
be checked. Display messages and
warning/indicator lamps
483
483

W
W
ar
ar ning/indicat
ning/indicat or lampP
or lam pP ossible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions
#
Electrical fault warning lamp *T
hered electrical fault warning lamp is lit.
There is a fault in the electrics. #
Notethe messages on the instrument displa y.
æ
Fu elreser vewarning lamp
lights up *T
he yellow fuel reser vewarning lamp lights up while the engine is running.
The fuel supply has dropped into there ser verange. #
Refuel. 484
484
Display messages and
warning/indicator lamps

A
A
ctiv
ctiv e P
e P ar
ar king Assist
king Assist
Exiting a parking space.......................... 268
Fu nction................................................ 265
Pa rking.................................................. 266
System limitations..................................2 65
A
A ctiv
ctiv e Ser
e Ser vice Sy
vice Sy st
stem PL
em PL US
US
see ASS YST PLUS
A A ctiv ctiv e Speed Limit Assist
e Speed Limit Assist
Display................................................... 236
Fu nction................................................ 236
A
A ctiv
ctiv eSt
e St eer
eer ing Assist
ing Assist
Ac tivating/deactivating.......................... 240
Ac tive Emer gency Stop Assist................ 240
Fu nction................................................ 238
System limits......................................... 238
A
A dap
dap tiv
tive br
e br ak
ake lights
e lights .................................... 226
A
A dap
dap tiv
tive cr
e cr uise contr
uise contr ol
ol
see Active Distance Assist DISTRONIC
A
A dap
dap tiv
tive Highbeam Assist
e Highbeam Assist
Ac tivating/deactivating.......................... 140
Fu nction................................................ 139
A
A dap
dap tiv
tive Highbeam Assis
e Highbeam Assist Plus t Plus
Fu nction................................................ 140
Switching on/o..................................... 141 A
A dBlue
dBlue ®
®
Ad ditives................................................ 398
Capacity................................................ 399
No tes..................................................... 192
Purit y.................................................... .398
To pping up............................................ .192
A
A dditional door lock
dditional door lock ....................................... 86
A A dditiv
dditiv es
es
Ad Blue ®
................................................ .398
Engine oil............................................... 399
Fu el....................................................... 396
A A dditiv dditiv es (A
es (AdBlue
dBlue ®
®
)
)
see AdBlue ®
A
A dditiv
dditiv es (engine oil)
es (engine oil)
see Additives
A
A dditiv
dditiv es (fuel)
es (fuel)
see Fuel
A
A djus
djus ting t
ting t he headlam
he headlam p r
p range
ange ...................... 135
ATer
ATer -sales
-sales ser
service
vice
see ASS YST PLUS
Air conditioning menu
Air conditioning menu Calling up.............................................. 154 Air dis
Air distr
tribution
ibution
Setting................................................... 153
Setting (MBUX multimedia system)......... 155
Air inlet Air inlet see Air-water duct
Air pr
Air pr essure
essure
see Tyre pressure
Air v
Air v ents
ents
Ad justing (front)..................................... 160
Ad justing (rear)...................................... 161
Air v
Air v ents
ents
see Air vents
Air
Air -conditioning syst
-conditioning syst em
em
see Climate cont rol
Air
Air -r
-recir
ecir culation mode (wit
culation mode (wit h
h/ne
/ne
par
par ticle
ticle pr
pre/lt
e/lt er)
er).......................................... 155
Air
Air -w
-wat
ater duct
er duct
Ke eping free.......................................... 337
Airbag
Airbag Activation................................................ 47
Fr ont airbag (driver, front passenger)........ 53
Installation locations................................ 53
Knee airbag............................................. 53 Index
493
493

Overview.................................................
.53
PA SSENGER AIR BAG indicator la mps...... 57
Pr otection................................................ 54
Re duced pr otection.................................. 55
Side airbag.............................................. 53
Wi ndow airbag......................................... 53
Air0 ow
Air0ow
Setting................................................... 153
Alar Alar m syst m syst em
em
see ATA (anti-theT alarm system)
All-wheel dr
All-wheel dr ive
ive
see 4M ATIC
Ambient lighting
Ambient lighting Setting (MBUX multimedia system)........ .142
Andr
Andr oid A
oid A uto
uto
see Smartphone integ ration
Animals
Animals Pets in theve hicle.................................... 80
Anti-loc
Anti-loc k br
k braking syst
aking syst em
em
see ABS (Anti-lock Braking System)
Anti-skid c
Anti-skid c hains
hains
see Sn owchains Anti-t
Anti-theT
heTprot
pr otection
ection
Ad ditional door loc k................................. 86
Immobiliser.............................................. 99
Anti-t
Anti-theT heTprot
pr otection
ection
see ATA (anti-theT alarm system)
Anticipat
Anticipat or
ory occupant pr ot
y occupant pr otection
ection
see PRE-SAFE ®
(anticipatory occu-
pant pr otection)
see PRE-SAFE ®
PLUS (anticipatory
occupant pr otection plus)
Apple CarPlay
Apple CarPlay ®
®
see Smartphone integ ration
Assist Assist ance syst ance syst ems
ems
see Driving saf ety sy stem
ASS YS
ASS YST PL
T PL US
US
Battery disconnection period s................ 331
Displaying the service due dat e.............. 330
Fu nction/no tes...................................... 330
Re gular maintenance work..................... 330
Special service requ irements................. 330
AT
ATA A(anti-t
(anti-theT heTalar
alarm syst
m syst em)
em)
Deactivating the alarm........................... 100
Fu nction.................................................. 99
Interior pr otection function.....................1 01Priming/deactivating interior pr
otec-
tion........................................................ 101
Priming/deactivating tow- awa y pro-
te ction................................................... 101
To w- awa y protection function................. 100
A
A TTENTION ASSIST TTENTION ASSIST
Function................................................ 227
Setting.................................................. .229
System limitations.................................. 227
A A tt tt ention assist
ention assist ant
ant
see ATTENTION ASSIST
A
A ut
ut hor
hor ised w
ised w ork
orkshop
shop
see Quali/ed specialist workshop
A
A ut
ut omatic car w
omatic car w ash mode
ash mode
Ac tivating............................................... 339
A
A ut
ut omatic co-dr
omatic co-dr iv
iver airbag
er airbag shut
shuto.
o.
Fu nction of co-driver airbag shuto........... 56
A
A ut
ut omatic dist
omatic dist ance contr
ance control
ol
see Active Distance Assist DISTRONIC
A
A ut
ut omatic dr
omatic dr iving lights
iving lights ................................ 135
A
A ut
ut omatic engine st
omatic engine st art
art
see ECO start/stop function 494
494
Index

A
A
ut
ut omatic engine st
omatic engine st op
op
see ECO start/s top function
A
A ut
ut omatic fr
omatic fr ont passeng
ont passeng er airbag
er airbagshut
shuto.
o.
PA SSENGER AIR BAG indicator la mps...... 57
A
A ut
ut omatic measur
omatic measur es
esaTer
aTer an accident
an accident ............ 61
A
A ut
ut omatic mirr
omatic mirr or f
or folding function
olding function
Ac tivating/deactivating.......................... 152
A
A ut
ut omatic tr
omatic tr ansmission
ansmission
DIRECT SELECT le ver............................. 183
Drive prog rams...................................... 178
DY NAMIC SELECT switch....................... 178
Engaging drive position.......................... 185
Engaging reve rsege ar............................ 184
Kickdown............................................... 186
Manual gear changing........................... .185
Selecting park position........................... 184
St eering wheel gearshiT paddles............ 185
Tr ansmission position displ ay................. 183
Tr ansmission position s........................... 183
A
A ut ut omatic tr
omatic tr ansmission (pr
ansmission (problem) oblem)
see Transmission (problem)
Axle load
Axle load Perm issible............................................ 392
Tr ailer operatio n..................................... 408 B
B
Bag hook
Bag hook..................................................... 126
Ball neck
Ball neck Folding out/in........................................ 271
B B AS (Br AS (Br ak
ake Assis
e Assist Syst t System)
em)........................... 222
Batt
Batt ery
ery
see High-voltage battery
Batt
Batt er
ery (high-v
y (high-v olt
oltag
age on-boar
e on-boar d electr
d electrical
ical
syst
syst em)
em)
see High-voltage battery
Batt
Batt er
ery (ke
y (ke y)
y)
Re placing................................................. 84
Batt
Batt er
ery (v
y (v ehicle)
ehicle)
Charging (Remo teOnline)..................... .167
No tes..................................................... 354
No tes (starting assis tance and charg-
ing)........................................................ 355
Batt
Batt er
ery oper
y oper ation
ation......................................... 162
Belt
Belt
see Seat belt
Bicy
Bicy cle r
cle r ack
ack
Load capacit y........................................ 407 Tr
ailer operatio n.................................... .274
Blind Spo
Blind Spo t Assist
t Assist
Ac tivating/deactivating.......................... 252
Fu nction................................................ 249
System limi tations.................................. 249
Blow
Blow er
er
see Clima tecont rol
BlueTEC
BlueTEC see AdBlue ®
Bonnet
Bonnet Function (active bonnet)......................... 331
Opening/closing.................................... 332
Re setting (active bonn et)........................ 331
Boo
Boo t lid t lid
see Tailgate
Br
Br ak
ak e Assis
e Assist Syst t System
em
see BAS (Brake Assist System)
Br
Br ak
ak e
e0uid
0uid
No tes..................................................... 401
Br
Br ak
ak e f
e f or
orce disce distr tribution
ibution
EBD (Elect ronic Brake forc e Distribu-
tion)....................................................... 224 Index
495
495

Cleaning
Cleaning
see Care
Cleaning
Cleaning 0uid
0uid
see windscreen washer 0uid
Climat
Climat e contr
e contr ol
ol
Ac tivating/deactivating.......................... 154
Ac tivating/deactivating the A/C func-
tion (MBUX multimedia system).............. 154
Ac tivating/deactivating the synchro-
nisation function (control panel).............1 55
Ac tivating/deactivating the synchro-
nisation function (MBUX multimedia
system).................................................. 155
Air-recirculation mode (with /ne parti-
cle pre/lter)...........................................1 55
Au tomatic control................................. .154
Calling up the air conditioning menu....... 154
Demisting the windscreen...................... 153
Demisting windo ws................................ 155
Fr ont air vents........................................ 160
Immediate pre-entry clima tecont rol....... 158
No te...................................................... 153
Pre-entry climate control at depa rture
time.......................................................1 56
Pre-entry climate control using theke y... 156 Re
ar air vents......................................... 161
Re sidual heat......................................... 155
Setting (MBUX multimedia system)......... 154
Setting the air distribution...................... 153
Setting the air0ow.................................. 153
Setting theve hicle interior temp era-
ture....................................................... 153
St ationary heater/ ventilation................. 158
Switching the A/C function on/o.
(control panel)....................................... 154
Switching there ar wind owheater
on/o.................................................... 153
THERM ATIC cont rol panel...................... 153
THERMOTRONIC control panel............... 153
Ve ntilating theve hicle (con venience
opening).................................................. 94
Clot
Clot hes hook hes hook ................................................ 126
Co-dr Co-dr iv iver airbag
er airbag shut
shut o.
o.
see Automatic co-driver airbag shuto.
Coc
Coc kpit
kpit
Overview.............................................. 6, 10
Co.ee
Co.ee cup symbol
cup symbol
see ATTENTION ASSIST Collapsible spar
Collapsible spar
e wheel
e wheel
In0a ting................................................ .387
No tes..................................................... 386
Collision det
Collision det ection (park
ection (parked v
ed vehicle)
ehicle)
In fo rm ation........................................... .218
Combination switch
Combination switch ..................................... 136
Com
Com ponent-speci/c
ponent-speci/c inf
infor
ormation
mation................... 391
Com
Com put
puter
er
see On-board computer
Conv
Conv enience closing
enience closing...................................... 94
Conv
Conv enience opening
enience opening..................................... 94
Coolant (engine)
Coolant (engine) Levelch eck............................................ 336
No tes..................................................... 401
Cooling
Cooling see Climate control
Cop
Cop yr
yright
ight....................................................... 45
Cor
Cor ner
nering light
ing light............................................. 138
Cr
Cr oss
oss tr
tra1c
a1c (w
(war
arning)
ning)
see Manoeuvring assis tance
Cr
Cr oss
oss Tr
Tra1c
a1c Alert
Alert........................................ 270 498
498
Ind
ex