2021 MERCEDES-BENZ A-CLASS SALOON service

#
Take care toonly connect battery term i-
nals of identical polarity when receiving
starting assistance. #
Obser vethe sequence described for
connecting and disconnecting the jump
leads when receiving starting assistance. #
Do not connect or disconnect the bat-
te ry term inals while the engine is run-
ning. &
W
W ARNI NG
ARNI NGRisk of explosion due toexplo-
sive mixture of gases
An explosive mixture of gases can escape
from the battery during charging and starting
assis tance. #
Fire , naked 0ames, smoking and creating
spar ksmust be avoided. #
Make sure there is adequate ventilation. #
Do not stand overth e batter y. &
W
WARNI NG
ARNI NGRisk of explosion from a frozen
battery
A dischar ged battery may freeze at temp era-
tures slightly abo veor below freezing point.
During starting assistance or battery charging,
battery gas can be released. #
Always allow a battery tothaw before
ch arging it or per form ing starting assis-
ta nce. If
th e indicator/warning lamps in the inst rument
clus ter do not light up at low temp eratures, it is
ve ry likely that the dischar ged battery has frozen.
In this case you may neither jump-start theve hi-
cle nor charge the batter y.
The service life of a bat tery that has been thawed
may be dramatically shor tened. The starting char-
acteristics may be impaired, especially at low
te mp eratures.
It is recommended that you ha veath awe d battery
ch ecked at a quali/ed specialist workshop. *
N
NO OTE
TE Damage caused bynume rous or
ex tended attem ptsto start the engine Numerous or
extended attem ptsto start the
engine may damage the catalytic con verter
due tonon-combusted fuel. #
Avoid numerous and extended attem pts
to start the engine. Obser
vethefo llowing points during starting assis-
ta nce and when charging the batter y:
R Only use undamaged jump lead/charging
cables with a su1cient cross-section and
insulated term inal clamps.
R Non-insulated parts of thete rm inal clamps
must not come into contact with other me tal
parts while the jump lead/charging cable is
connected tothe battery/jump-start connec-
tion point.
R The jump lead/charging cable must not come
into contact with any parts which may mo ve
when the engine is running.
R Always make sure that nei ther you nor the bat-
te ry is electros tatically charge d. Breakdown assistance
351 351

*
N
NO
OTE
TE Damage tovehicle body or suspen-
sion components caused by/tted snow
ch ains On 4MATIC
vehicles, if you /t snow chains on
th ere ar wheels, you can damage vehicle body
or suspension components. #
On 4MATIC vehicles, only /t snow chains
on the front wheels. *
N
NOOTE
TE Damage tothe wheel trim from /t-
ted snow chains If snow
chains are /tted tosteel wheels, the
wheel trims can be damaged. #
Remo vethe wheel trims of steel wheels
before /tting snow chains. Obser
vethefo llowing no tes when using snow
ch ains:
R Snow chains are only permissible for cer tain
wheel/tyre combinations. You can obtain
information about this from a Mercedes-Benz
Service Centre. R
For saf etyre asons, only use snow chains that
ha ve been speci/cally appr oved foryo ur vehi-
cle byMercedes-Benz, or snow chains with
th e same quality standard.
R If snow chains are /tted, the maximum per-
missible speed is 50 km/h.
R V
V ehicles wit
ehicles wit h A
h Activ
ctiv e P
e Par
arking Assist
king Assist: :do not use
Ac tive Parking Assist when snow chains are
/tted.
% You can permanently limit the maximum
speed for driving with winter tyres
(/ page 226).
% You can deactivate ESP ®
to pull away
( / page 218). This allo ws the wheels tospin,
achieving an increased driving forc e. T
T
yr
yr e pr
e pr essure
essure N
No
ot
tes on tyr
es on tyr e pr
e pressure
essure &
W
WARNING
ARNING Risk of accident due toinsu1-
cient or excessive tyre pressure
Un derin0a tedorove rin0ated ty res pose in par-
ticular thefo llowing risks:
R The tyres can burst.
R The tyres can wearexcessively and/or
une venly.
R The driving characteristics as well as the
stee ring and braking characteristics may
be greatly impaired. #
Comply with there commended tyre
pressure and check the tyre pressure of
all tyres, including the spare wheel, regu-
lar ly:
R monthly
R when the load changes
R before embarking on a lon ger journey 364
364
Wheels and tyres

R
if operating conditions change, e.g. o.-
ro ad driving #
Adjust the tyre pressure, if necessar y.Ty
re pressure which is too high or too low can:
R Shor tenth e service life of the tyres.
R Cause increased tyre damage.
R Adve rsely a.ect driving characteristics and
th us driving saf ety, e.g. due toaquaplaning. &
W
WARNING
ARNING Risk of accident due torepea-
te d pressure drop in the tyres
The wheels, valves or tyres could be damaged.
To o low a tyre pressure can lead tothe tyres
bursting. #
Examine the tyres forfo re ign objects. #
Check whe ther the tyre has a puncture
or theva lve has a leak. #
Ifyo u are unable torectify the damage,
contact a quali/ed specialist workshop. Information on
there commended tyre pressure
fo rth eve hicle's factor y-/tted tyres can be found
on the tyre pressure table on the inside of the fuel
/ller 0ap (/ page 365).
Use a suitable pressure gauge tocheck the tyre
pressure. The outer appearance of a tyre does not
permit any reliable conclusion about the tyre pres-
sure.
Only cor rect tyre pressures when the tyres are
cold. Conditions for cold tyres:
R The vehicle has been par ked with the tyres out
of direct sunlight for at least thre e hours.
R The vehicle has tr avelled less than 1.6 km.
The vehicle's tyres heat up when driving. As the
te mp erature of the tyres increases, so too does
th e tyre pressure.
V
V ehicles wit ehicles wit h a tyr
h a tyre pr
e pr essur
essur e monit
e monit or
oring syst
ing syst em:
em:
yo u can also check the tyre pressure using the
on-board computer.
Not Not es on tr
es on tr ailer oper
ailer oper ation
ation
Alw ays in0ate there ar axle tyres tothere com-
mended tyre pressures on the tyre pressure table
fo r increased load. T
T
yr
yr e pr
e pr essur
essur e t
e table
able The tyre pressure
table is on the inside of the fuel
/ller 0ap. The tyre pressure
table sho ws there commended
tyre pressure for all tyres appr ovedfo rth is vehi-
cle. The recommended tyre pressures apply for
cold tyres under various operating conditions, i.e.
loading and/or speed of theve hicle. Wheels and tyres
365
365

If one or more tyre sizes precede a tyre pressure,
th efo llowing tyre pressure information is only
va lid forth ose tyre sizes and their respecti veload
condition.
If th e preceding tyre sizes are complemented by
th e+ symbol, the tyre pressure information
fo llowing sho wsalternative tyre pressures. Fuel
consum ption may then increase slightl y.
The load conditions "pa rtially laden" and "fully
laden" are de/ned in theta ble for di.erent num-
bers of passengers and amounts of luggage. The
actual number of seats may di.er from this. T T
yr
yr e pr
e pr essur
essur e monit
e monit or
oring syst
ing syst em
em F
F
unction of t
unction of t he tyr
he tyre pr
e pressur
essur e monit
e monit or
oring syst
ing syst em
em
The system checks the tyre pressure and the tyre
te mp erature of the tyres /t tedtotheve hicle by
means of a tyre pressure sensor.
The tyre pressure and the tyre temp erature
appear in the on-board computer (/ page 366).
If th ere is a substantial pressure loss or if the tyre
te mp erature is excessive, you will be warned with
display messages (/ page 458) ortheh wa
rning lamp in the inst rument cluster
(/ page 482).
The tyre pressure monitoring system is only an
aid. It is the driver's responsibility toset the tyre
pressure tothere commended cold tyre pressure
suitable forth e operating situation.
In most cases, the tyre pressure monitoring sys-
te m will automatically update the new refere nce
va lues aTer you ha vechanged the tyre pressure.
Yo u can, ho wever, also update there fere nce val-
ues byrestarting the tyre pressure monitoring
system manually (/ page 367).
Syst
Syst em limits em limits
The system may be impaired or may not function
particular lyin thefo llowing situations:
R incor rect refere nce values were ta ught in
R sudden pressure loss caused byafo re ign
object penetrating the tyre, forex ample
R there is a malfunction caused byano ther radio
signal source Chec
Chec king t
king t he tyr
he tyr e pr
e pressur
essur e wit
e with t
h the tyr
he tyr e pr
e pressure
essure
monit
monit or
oring sy
ing sy st
stem
em
R
R eq
eq uir
uir ements:
ements:
R The vehicle is switched on.
On-board computer: 4 Service 5
Tyres
One of thefo llowing displa ysappears:
R Current tyre pressure and tyre temp erature of
th e individual wheels: R
Tyre pressures will be displayed after a few
minutes of driving 366 366
Wheels and tyres

R
Tyre pressure monitor active :th ete ach-in
process of the system is not yetcomple te. The
tyre pressures are already being monitored. #
Compare the tyre pressure with there com-
mended tyre pressure forth e cur rent ope rat-
ing condition (/ page 365).Additionall y,
obser vethe no tes on cold tyres
(/ page 364).
% The values displa yed in the on-board com-
puter may deviate from those of the tyre pres-
sure gauge as they referto sea le vel.At high
ele vations, the tyre pressure values indicated
by a pressure gauge are higher than those
shown bythe on-board computer. In this case,
do not reduce the tyre pressure.
R
R est
est ar
arting t
ting t he tyr
he tyr e pr
e pressur
essur e monit
e monit or
oring syst
ing syst em
em
R
R eq
eq uir
uir ements:
ements:
R The recommended tyre pressure is cor rectly
set forth ere specti veoperating status on all of
th e wheels (/ page 364).
Re start the tyre pressure monitoring system in the
fo llowing situations:
R The tyre pressure has changed. R
The wheels or tyres ha vebeen changed or
ne wly /tted.
On-board computer: 4 Service 5
Tyres #
Swipe down wards on Touch Control on the
leT-hand side of the steering wheel.
The Use current pressures as new reference
values? message is shown in the Instrument
Displa y. #
Torestart, press Touch Control on the leT-
hand side of the steering wheel.
The Tyre press. monitor restarted message is
shown in the Instrument Displa y.
Cur rent wa rning message s are deleted and
th eye llow h warning lamp goes out.
ATer you ha vebeen driving for a few minutes,
th e system checks whe ther the cur rent tyre
pressures are within the speci/ed range. The
cur rent tyre pressures are then accep ted as
re fere nce values and monitored.
Be sure toalso pay attention tothefo llowing rela-
te dto pic:
R Notes on tyre pressure (/ page 364) T
T
yr
yr e pr
e pr essur
essur e loss w
e loss w ar
arning syst
ning syst em
em F
F
unction of t
unction of t he tyr
he tyre pr
e pressur
essur e loss w
e loss w ar
arning syst
ning syst em
em
The tyre pressure loss warning system warnsthe
driver bymeans of display messages when there
is a se vere tyre pressure loss.
Syst
Syst em limits
em limits
The system may be impaired or may not function
particula rly in thefo llowing situations:
R incor rect refere nce values were ta ught in
R sudden pressure loss caused byafo re ign
object penetrating the tyre, forex ample
R aneven pressure loss on more than one tyre
occurs
The system has a restric ted or dela yed function
particular lyin thefo llowing situations:
R poor ground conditions, e.g. snow or grav el
R driving with snow chains
R when adopting a very sporty driving st yle with
high cornering speeds or sudden acceleration
R driving with a very heavy or lar getrailer
R driving with a high load Wheels and tyres
367
367

The tyre pressure loss
warning system is only an
aid. It is the driver's responsibility toset the tyre
pressure tothere commended cold tyre pressure
suitable forth e operating situation and tocheck
it.
Be sure toalso obser vethefo llowing fur ther rela-
te d subjects:
R Notes on tyre pressure (/ page 364)
R Displ aymessages about the tyres
(/ page 458)
R
R est est ar
arting t
ting t he tyr
he tyr e pr
e pressur
essur e loss w
e loss w ar
arning syst
ning syst em
em
R
R eq
eq uir
uir ements:
ements:
R The recommended tyre pressure is cor rectly
set forth ere specti veoperating status on all
wheels.
Re start the tyre pressure loss warning system in
th efo llowing situations:
R The tyre pressure has changed.
R The wheels or tyres ha vebeen changed or
ne wly /tted. On-board computer:
4 Service 5
Tyres #
Swipe down wards on Touch Control on the
leT-hand side of the steering wheel.
The Run Flat Indicator active Restart mes-
sage is shown in the displa y. #
Tobegin restart, press Touch Control on the
leT-hand side of the steering wheel.
The Tyre pressure now OK? message is
shown in the displa y. #
Select Yes. #
Tocon/rm restart, press Touch Control on the
leT-hand side of the steering wheel.
The Run Flat Indicator restarted message is
shown in the displa y.
ATer you ha vedriven for a few minutes, the
tyre pressure loss warning system monitors
th e set tyre pressures of all the tyres.
Be sure toalso pay attention tothefo llowing rela-
te dto pic:
R Notes on tyre pressure (/ page 364) Wheel c
Wheel c
hange
hange N
No
ot
tes on selecting,
es on selecting, /tting
/ttingand r
and replacing tyr
eplacing tyr es
es *
N
NOOTE
TE Mercedes-AMG vehicles #
Obser vethe no tes in the Supplement.
Yo u could otherwise failto recognise
dangers. &
W
WARNING
ARNING Risk of accident due toincor-
re ct wheel and tyre dimensions
If wheels and tyres of the wrong size are /t ted,
th e service brakes or components in the brake
system and in the wheel suspension may be
damaged. #
Alwaysre place wheels and tyres with
th ose that ful/l the speci/cations of the
original part.
Fo r wheels, pay attention tothefo llowing:
R Designation
R Type 368
368
Wheels and tyres

N
N
o
ot
tes on t
es on t ec
echnical data
hnical data
* NO
NOTE
TEMercedes-AMG vehicles #
Obser vethe no tes in the Supplement.
Yo u could otherwise failto recognise
dangers. The
tech nical data was de term ined in accordance
with EU Directives. The data stated only applies to
ve hicles with standard equipment. You can obtain
fur ther information from a Mercedes-Benz Service
Centre.
Onl Onl y f
y for cert
or cert ain countr
ain countr ies:
ies:you can /n dvehicle-
speci/c vehicle data in theCO C documents (CER-
TIFIC ATE OF CONFORMITY). These documents
are deli vered with your vehicle. On-boar
On-boar
d electr
d electronics
onics N
No
ot
tes on t
es on t am
amper
per ing wit
ing wit h t
h t he engine electr
he engine electr onics
onics *
N
NOOTE
TE Prematu rewe arthro ugh improper
maintenance Improper maintenance may cause
vehicle
components towe ar more quickly and the
ve hicle's operating permit may be in validated. #
Always ha veworkon the engine elec-
tronics and related components car ried
out at a quali/ed specialist workshop. T
T
w
w o-wa
o-wa y r
y radios
adios N
No
ot
tes on
es on /tting
/tting tw
two-wa
o-wa y r
y radios
adios &
W
WARNING
ARNING Risk of accident due to
improper workon two-w ayradios
If two-w ayradios are manipulated or retro/t-
ted incor rectl y,the electromagnetic radiation
from the two-w ayradios can inter fere with the
ve hicle elect ronics and jeopardise the operat-
ing saf ety of theve hicle. #
You should ha veall workon electrical
and electronic components car ried out
at a quali/ed specialist workshop. &
W
WARNING
ARNING Risk of accident due to
improper operation of two-w ayradios
If yo u use two-w ayradios in theve hicle
improper ly,th eir electromagnetic radiation
can disrupt theve hicle's elect ronics. This is
th e case in thefo llowing situations, in particu-
lar:
R The two-w ayradio is not connected toan
ex terior aerial.
R The exterior aerial is /tted incor rectly or is
not a lo w-re0ection aerial.
This could jeopardise the operating saf ety of
th eve hicle. #
Have the lo w-re0ection exterior aerial /t-
ted at a quali/ed specialist workshop. #
When operating two-w ayradios in the
ve hicle, alw ays connect them tothe lo w-
re 0ection exterior aerial. Te
ch nical data
381
381

can be
found on the information label in the fuel
/ller 0ap or on the fuel dispenser or pump nozzle
suitable foryo ur vehicle thro ughout Europe.
If th eav ailable fuel is not su1ciently low in sul-
phur, this can produce unpleasant odours.
The recommended octane number foryo ur vehi-
cle can be found on the information label in the
fuel /ller 0ap.
If th ere commended fuel is not available, you may
also temp orarily use regular unleaded petrol with
an octane number of at least 91 RON.This may
re duce engine output and increase fuel consump-
tion.
Ne verre fuel using petrol wi than even lo werRO N.
Fu rther information on fuel can be obtained at a
/lling station or a quali/ed specialist workshop.
Inf
Inf or ormation on additiv
mation on additiv es in pe
es in petr
trol (v
ol (v ehicles with
ehicles with
pe
pe tr
trol engine)
ol engine)
No tethe inst ructions about operating 0uids
(/ page 385). *
N
NO OTE
TE Damage from use of unsui table
additives Even small amounts of
the wrong additive may
lead tomalfunctions occur ring. #
Only add cleaning additives recommen-
ded byMercedes-Benz tothe fuel. Mercedes-Benz
recommends that you use brand-
name fuels with additives.
In some countries, the fuel available may not ha ve
su1cient additives. Deposits could build up in the
fuel injection system as a result. In this case, in
consultation with a Mercedes-Benz service
centre, mix the fuel with the cleaning additive rec-
ommended byMercedes-Benz. Obser vethe no tes
and mixing ratios indica ted on theta nk.
Inf
Inf or ormation on fuel q
mation on fuel q uality f
uality for v
or vehicles wit
ehicles wit h a die-
h a die-
sel engine
sel engine
Gener Gener al not
al notes
es
No tethe inst ructions about operating 0uids
(/ page 385). &
W
WARNING
ARNING Risk of /re from fuel mixture
If yo u mix diesel fuel with petrol, the 0ash
point of the fuel mixture is lo werth an that of
pure diesel fuel. #
Neverre fuel using petrol in diesel
engines. #
Never mix petrol with diesel fuel. *
N
NOOTE
TE Damage caused bythe wrong fuel Even small amounts of
the wrong fuel could
re sult in damage tothe fuel system, the
engine and the emission control system.
V
V ehicles wit
ehicles wit h a diesel par
h a diesel par ticulat
ticulate
e/lt
/lt er:
er: #
Only refuel using sulphu r-free diesel fuel
th at conforms toEuropean standard
EN 590, or an equivalent speci/cation.
In count ries without sulphur-free diesel
fuel, refuel using only lo w-sulphur diesel
fuel with a sulphur content less than
50 ppm.
V
V ehicle wit
ehicle wit hout diesel par
hout diesel par ticulat
ticulate
e/lt
/lt er:
er: 388
388
Te
ch nical data