2021 MERCEDES-BENZ A-CLASS SALOON air condition

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

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
oring 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
acter
eris
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 226). 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 364)
R Tyre pressure table (/ page 365)
R Notes on the emer gency spa rewheel
(/ page 378) 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. Wheels and tyres
371
371

Displa
Displa
y messag
y messag es P
es Possible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions
6
Left windowbag malfunc-
tion Consult work-
shop (examp le) *T
he cor responding restraint system is malfunctioning (/ page 47). &
W WARNING
ARNING Risk of injury or fatal injury due toa malfunction in the windowbag
The windowbag might be triggered unintentionally or might not be triggered at all in theev ent of an accident. #
Have the windowbag checked and repaired immediately at a quali/ed specialist workshop. Front-passenger airbag dis-
abled See Owner's Manual
*T
he front passen ger airbag has been disabled even though an adult or a person of adult build is on the front passenger
seat. If additional forc es are applied tothe seat, thewe ight the system de tects may be too lo w. &
W WARNI NG
ARNI NG‑ Risk of injury or evenfata l injury when the front passenger airbag is disabled
If th e front passenger airbag is disabled, It will not be deplo yed in theev ent of an accident and cannot per form its
intended pr otective function.
A person in the front passenger seat could then, forex ample, come into contact with theve hicle interior, especially
if th e person is sitting too close tothe dashboard. #
Beawa reofthe status of the front passenger airbag bo thbefore and during the journe y. #
Stop theve hicle immediately in accordance with the tra1c conditions. #
Make sure that no objects are trapped under the front passenger seat. #
Check the status of automatic front passenger airbag actuation (/ page 57).#
If necessar y,consult a quali/ed specialist workshop immediatel y.404
404
Display message
s andwarning/indicator lamps

Displa
Displa
y messag
y messag es P
es Possible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions
Front-passenger airbag
enabled See Owner's Man-
ual *T
he front passen ger airbag will be enabled while theve hicle is in motion in thefo llowing situations:
R even when a child, a small adult or an object weighing less than the system weight thre shold is located on the front
passenger seat
R even when the front passenger seat is not occupied
The system may de tect objects or forc es that are adding tothewe ight applied tothe seat. &
W WARNING
ARNING Risk of injury or death when using a child restraint system while the front passenger airbag is ena-
bled
If yo u secure a child in a child restraint system on the front passenger seat and the front passenger airbag is ena-
bled, the front passenger airbag can deploy in theev ent of an accident.
The child could be struck bythe airbag. #
Ensure, bo thbefore and during the journe y,that the status of the front passenger airbag is cor rect.
NEVER use a rear wa rdfacing child restraint on a seat pro tected byan ACTIVE AIRBAG in front of it, DEATH or
SERIOUS INJURY tothe CHILD can occur. #
Stop theve hicle immediately in accordance with the tra1c conditions. #
Make sure that no objects are trapped under the front passenger seat. #
Check the status of automatic front passenger airbag actuation (/ page 57).#
If necessar y,consult a quali/ed specialist workshop immediatel y. Display messages and
warning/indicator lamps
405
405

Displa
Displa
y messag
y messag es P
es Possible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions #
Refuel immedia tely.
Subse quentl y,there may be temp orary restrictions in theav ailability of elect ric mode over a driving distance of
50 km.
If th ere is fuel in theve hicle, there is a fault with the combustion engine. #
Consult a quali/ed specialist workshop.
"Electric" drive program
currently unavailable *T
hecharge leve l of the high-voltage battery is not su1cient forth e Electric drive prog ram.
Char gethe high-voltage battery (/ page 188).
Reduced drive system per-
formance See Owner's
Manual *T
he drive system switches toemer gency ope ration mode due toa malfunction. #
Drive on carefull y. #
Consult a quali/ed specialist workshop.
Û
Battery overheated Stop,
everybody out! Outdoors if
possible *T
he high- voltage battery has overheated. There is a risk of /re. #
Stop theve hicle immediately in accordance with the tra1c conditions. #
If possible, stop theve hicle in the open air and ensure that all vehicle occupants getout.
% Supporting vehicle functions may activate automaticall y,e.g. the air-recirculation mode as part of climate control. #
Do not continue driving. #
If smoke is present, lea vethe danger zone and call the /re service immediatel y. #
Consult a quali/ed specialist workshop even if there are no extern al signs of a /re. Displ
aymessages and warning/indicator lamps
417 417

Displa
Displa
y messag
y messag es P
es Possible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions
Head-up display inoperative *The head-up displ ayhas an internal er ror. #
Consult a quali/ed specialist workshop.
Ù
Steering malfunction
Increased physical effort
See Owner's Manual *T
he po wer steering assistance is malfunctioning. &
W WARNING
ARNING Risk of an accident due toaltered steering characteristics
If th e po wer assistance of the steering fails partially or comple tely,yo u will need touse more forc eto stee r. #
If safe steering is possible, drive on carefull y. #
Visit or consult a quali/ed specialist workshop immediatel y. Ù
Steering malfunction Stop
immediately See Owner's
Manual *T
he steering is malfunctioning. Steering capability is signi/cantly impaired. &
W WARNING
ARNING Risk of accident if steering capability is impaired
If th e steering does not function as intended, theve hicle's operating saf ety is jeopardised. #
Pull over and stop theve hicle safely as soon as possible, paying attention toroad and tra1c conditions. Do
not continue driving under any circums tances. #
Consult a quali/ed speciali stwo rkshop. Displ
aymessages and warning/indicator lamps
423
423

Displa
Displa
y messag
y messag es P
es Possible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions
ÿ
Coolant Stop vehicle
Switch engine off *T
he coolant is too hot. #
Stop immediately in accordance with the tra1c conditions and switch o. theve hicle. &
W WARNING
ARNING Risk of burns when opening the bonnet
If yo u open the bonnet in theev ent 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. #
Wait until the engine has cooled down. #
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 *T
here is a malfunction in the engine cooling system. #
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. 428
428
Display messages and
warning/indicator lamps