2021 MERCEDES-BENZ A-CLASS SALOON battery

Displa
Displa
y messag
y messag es P
es Possible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions
or #
If possible, continue driving at a steady speed and remo veyour foot from the clutch pedal. Do not let the clutch
drag.
The clutch will cool while theve hicle is in motion.
When the clutch has cooled down, the display message will disappear.
Auxiliary battery malfunc-
tion (white display message) *T
he auxiliary battery forth e automatic transmission is no longer being charge d. #
Consult a quali/ed specialist workshop. #
Until then, alw ays select park position jmanually before you switch o. theve hicle. #
Before leaving theve hicle, apply the electric parking brake.
Auxiliary battery malfunc-
tion (red display message) *V
Vehicles wit ehicles wit h manual tr
h manual tr ansmission:
ansmission: There is afault with the auxiliary batter y.
V
V ehicles wit
ehicles wit h aut
h automatic tr
omatic tr ansmission:
ansmission: The auxiliary battery forth e transmission is no longer being charge d. #
Consult a quali/ed specialist workshop. #
V
V ehicles wit
ehicles wit h aut
h automatic tr
omatic tr ansmission:
ansmission: untilthen, alw ays select park position jbefore you switch o. theve hicle. #
Before leaving theve hicle, apply the electric parking brake. 434
434
Display messages and
warning/indicator lamps

Displa
Displa
y messag
y messag es P
es Possible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions
Device detected at diagnos-
tics connection See Own-
er's Manual *T
hevehicle functions forfa ult de tection are restric ted.
At least one of the main functions of the Mercedes me connect system is malfunctioning. #
Obser vethe no tes on the diagnostics connection (/ page 38). #
Consult a quali/ed specialist workshop. Batt Batt
ery
ery Displa
Displa
y messag
y messag es P
es Possible causes/conseq
ossible causes/conseq uences and
uences andM
MSolutions
Solutions
#
12 V battery See Owner's
Manual *T
hevehicle is o. and the state of charge ofthe 12 V battery is too lo w. #
Switch o. elect rical consume rsthat are not requ ired. #
Drive for 30–60 minutes.
or #
Char gethe 12 V battery when stationary (/ page 352).
*I fth e message appears while theve hicle is switched on, this indicates an on-board electrical system malfunction. #
Consult a quali/ed specialist workshop.
#
See Owner's Manual *T
he 12 V battery is not being charge d. 456 456
Display messages and
warning/indicator lamps

Displa
Displa
y messag
y messag es P
es Possible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions
* NO
NOTE
TEPossible engine damage if you continue driving #
Do not continue driving under any circumstances. #
Consult a quali/ed speciali stwo rkshop. #
Stop immediately in accordance with the tra1c conditions and switch o. theve hicle. #
Consult a quali/ed specialist workshop.
#
Stop vehicle See Owner's
Manual *T
he 12 V battery is no lon ger being charge d and the state of charge istoo lo w.
* N
N O OTE
TE Possible engine damage if you continue driving #
Do not continue driving under any circumstances. #
Consult a quali/ed speciali stwo rkshop. #
Stop theve hicle immediately in accordance with the tra1c conditions. Do not continue driving. #
Switch o. theve hicle. #
Consult a quali/ed specialist workshop. Displ
aymessages and warning/indicator lamps
457
457

Displa
Displa
y messag
y messag es P
es Possible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions
#
Stop vehicle Leave engine
running *T
he 12 V battery charge leve l is too lo w. #
Stop theve hicle immediately in accordance with the tra1c conditions. Do not continue driving. #
Leavetheve hicle running #
Ifth e display message disappears: drive on. #
Ifth e display message does not disappear: consult a quali/ed specialist workshop. T T
yr
yr e pr
e pr essur
essur e monit
e monit or
or Displa
Displa
y messag
y messag es P
es Possible causes/conseq
ossible causes/conseq uences and
uences andM
MSolutions
Solutions
Tyre press. monitor cur-
rently unavailable *T
here is inter fere nce from a po werful radio signal source. As a result, no signals from the tyre pressure sensors are
being received. The tyre pressure monitoring system is temp orarily una vailable.
The tyre pressure monitoring system will restart au tomatically as soon as the cause has been recti/ed. #
Drive on.
Tyre press. monitor inoper-
ative *T
he tyre pressure moni toring system is malfunctioning. &
W WARNI NG
ARNI NGThere is a risk of an accident if the tyre pressure monitoring system is malfunctioning
The tyre pressure monitoring system cannot issue a warning if there is pressure loss in one or more of the tyres.
Ty res with insu1cient tyre pressure may impair the driving characteristics as well as steering and braking. #
Have the tyre pressure monitoring system checked at a quali/ed specialist workshop. 458
458
Displ
aymessages 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 #
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
475
475

Overview.................................................
.52
PA SSENGER AIR BAG indicator la mps...... 57
Pr otection................................................ 53
Re duced pr otection.................................. 55
Side airbag.............................................. 52
Wi ndow airbag......................................... 52
Air0 ow
Air0ow
Setting................................................... 147
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)........ .138
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............................................ 101
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................ 325
Displaying the service due dat e.............. 324
Fu nction/no tes...................................... 324
Re gular maintenance work..................... 324
Special service requ irements................. 324
AT
ATA A(anti-t
(anti-theT heTalar
alarm syst
m syst em)
em)
Deactivating the alarm........................... 102
Fu nction................................................ 101
Interior pr otection function.....................1 03Priming/deactivating interior pr
otec-
tion........................................................ 103
Priming/deactivating tow- awa y pro-
te ction................................................... 102
To w- awa y protection function................. 102
A
A TTENTION ASSIST TTENTION ASSIST
Function................................................ 221
Setting.................................................. .223
System limitations.................................. 221
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............................................... 333
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 ................................ 131
A
A ut
ut omatic engine st
omatic engine st art
art
see ECO start/stop function 486
486
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 ............ 60
A
A ut
ut omatic mirr
omatic mirr or f
or folding function
olding function
Ac tivating/deactivating.......................... 146
A
A ut
ut omatic tr
omatic tr ansmission
ansmission
DIRECT SELECT le ver............................. 177
Drive prog rams...................................... 172
DY NAMIC SELECT switch....................... 172
Engaging drive position.......................... 179
Engaging reve rsege ar............................ 178
Kickdown............................................... 180
Manual gear changing........................... .179
Selecting park position........................... 178
St eering wheel gearshiT paddles............ 179
Tr ansmission position displ ay................. 177
Tr ansmission position s........................... 177
A
A ut ut omatic tr
omatic tr ansmission (pr
ansmission (problem) oblem)
see Transmission (problem)
Axle load
Axle load Perm issible............................................ 384
Tr ailer operatio n..................................... 399 B
B
Ball neck
Ball neck Folding out/in........................................ 265
B
B AS (Br
AS (Br ak
ake Assis
e Assist Syst t System)
em)........................... 216
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)..................... .161
No tes..................................................... 349
No tes (starting assis tance and charg-
ing)........................................................ 350
Batt
Batt er
ery oper
y oper ation
ation......................................... 156
Belt
Belt
see Seat belt
Bicy
Bicy cle r
cle r ack
ack
Load capacit y........................................ 399
Tr ailer operatio n.................................... .268 Blind Spo
Blind Spo t Assist
t Assist
Ac tivating/deactivating.......................... 246
Fu nction................................................ 243
System limi tations.................................. 243
Blow
Blow er
er
see Clima tecont rol
BlueTEC BlueTEC see AdBlue ®
Bonnet Bonnet Function (active bonnet)......................... 325
Opening/closing.................................... 326
Re setting (active bonn et)........................ 325
Boo
Boo t lid
t lid
Closin g.................................................... 91
HANDS-FREE ACCESS............................. 92
Opening...................................................90
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..................................................... 393
Br
Br ak
ak e f
e f or
orce disce distr tribution
ibution
EBD (Elect ronic Brake forc e Distribu-
tion)....................................................... 218 Index
487
487

Br
Br
ak
ak es
es
ABS (Anti-lo ckBraking System).............. 215
Ac tive Brake Assist................................. 235
Ad aptive brake lights.............................. 220
BAS (Brake Assist System).................... .216
Driving tips............................................ 163
EBD (Electronic Brake forc e Distribu-
tion).......................................................2 18
HOLD function....................................... 219
Limited braking e.ect (salt-treated
ro ads)................................................... .163
Ne w/replaced brake linings/brake
discs...................................................... 162
Po st-collision brak e.................................. 60
Ru nning-in no tes.................................... 162
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........................................... 359
To wing away.......................................... 356
Tr anspo rting theve hicle........................ .357
Wheel chang e........................................ 373 Br
Br ea kdo
eakdo wn
wn
see Flat tyre
Butt
Butt ons
ons
St eering wheel....................................... 273 C
C
Calls
Calls Mercedes me......................................... 305
Camera
Camera
Information............................................ 214
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)............................................ 331
Car
Car -t
-to-X
o-X -Communication
-Communication
Displaying hazard warnings.................... 299
Care
Care 360° camera......................................... 336 Air-water duct........................................ 331
Au
tomatic car wash.............................. .331
Carpet................................................... 337
Decorative foil........................................ 335
Display................................................... 337
Exterior lighting...................................... 336
Head-up display..................................... 337
High-pressure cleaner............................3 33
Pa int...................................................... 334
Plastic trim............................................3 37
Re alwo od/trim elements..................... .337
Re versing camera..................................3 36
Ro of lining............................................. 337
Seat belt................................................ 337
Seat co ver............................................. 337
Sensors................................................. 336
St eering wheel....................................... 337
Ta ilpipes................................................ 336
Tr ailer hitc h............................................ 336
Ve hicle soc ketfo rth e high-voltage
battery................................................... 336
Wa shing byhand.................................... 334
Wheels/rims.......................................... 336
Wi ndo ws................................................ 336
Wi per blades.......................................... 336 488 488
Index