engine overheat MERCEDES-BENZ A-CLASS HATCHBACK 2021 Owners Manual

&
D
DAN
AN GER
GER Risk of fatal injuries caused by
ex haust gases
Combustion engines emit poisonous exhaust
ga ses such as carbon monoxide. Inhaling
th ese exhaust gases is hazardous tohealth
and leads topoisoning. #
Never lea vetheve hicle or, if present, the
stationa ryheater running in an enclosed
space without su1cient ventilation. &
W
WARNI NG
ARNI NGRisk of skidding and of an acci-
dent due toshiTing down on slippe ryroad
sur faces
If yo u shiT down on slippery road sur faces to
increase the engine braking e.ect, the drive
wheels may lose traction. #
Do not shiT down on slippery road sur fa-
ces toincrease the engine braking
e.ect. &
D
DAN
AN GER
GER Risk of fatal injury due topoison-
ous exhaust gases
If th eta ilpipe is bloc ked or su1cient ventila-
tion is not possible, poisonous exhaust gases
such as carbon monoxide may enter theve hi-
cle. This is the case if theve hicle gets stuck in
sno w,forex ample. #
Keep theta ilpipe and the area around
th eve hicle free from snow when the
ve hicle or the stationary heater is run-
ning. #
Open a wind owonthe side of theve hicle
fa cing away from the wind toensure an
adequate supply of fresh air. &
W
WARNING
ARNING Risk of accident due tothe
brake system overheating
If yo u lea veyour foot on the brake pedal when
driving, the brake system may overheat.
This increases the braking distance and the
brake system can even fail. #
Never use the brake pedal as a foot re st. #
Do not depress the brake pedal and the
accelerator pedal at the same time while
driving. *
N
NOOTE
TE Engine damage due toexcessively
high engine speeds The engine will be damaged if
you drive with
th e engine in theove rrev ving range. #
Do not drive with the engine in theove r-
re vving range. *
N
NOOTE
TE Causing wearto the brake linings by
permanently depressing the brake pedal #
Do not permanently depress the brake
pedal while driving. #
Touse braking e.ect of the engine, shiT
to a lo werge ar in good time. 170
170
Driving and parking

R
R
efuelling
efuelling R
R
efuelling t
efuelling t he v
he vehicle
ehicle &
W
WARNING
ARNING Risk of /re or explosion from
fuel
Fu els are highly 0ammable. #
Fire , naked 0ames, smoking and creating
spar ksmust be avoided. #
Before refuelling, switch o. theve hicle
and, if /tted, the stationary heater and
ke ep switched o. during /lling. &
W
WARNING
ARNING Risk of injury from fuels
Fu els are poisonous and hazardous toyour
health. #
Do not swallow fuel or let it come into
contact with skin, eyes or clo thing. #
Do not inhale fuel vapour. #
Keep children away from fuel. #
Keep doors and windo wsclosed during
th ere fuelling process. If
yo u or other people come into contact with
fuel, obser vethefo llowing: #
Immediate lyrinse fuel o. your skin with
soap and water. #
If fuel comes into contact with your eyes,
immediately rinse them thoroughly with
clean water. Seek medical at tention
immedia tely. #
Ifyo u swallow fuel, seek medical atten-
tion immediatel y.Do not induce vomit-
ing. #
Change immediately out of clo thing that
has come into contact with fuel. &
W WARNING
ARNING Risk of /re and explosion due
to electrostatic charge
Electrostatic charge can ignite fuel vapour. #
Before you open the fuel /ller cap or
ta ke hold of the pump nozzle, touch the
me tallic vehicle body. #
Toavo id creating ano ther electrostatic
ch arge , do not get into theve hicle again
during there fuelling process. &
W
WARNING
ARNING Risk of /re from fuel mixture
Ve hicles with a diesel engine:
If yo u mix diesel fuel with petrol, the 0ash
point of the fuel mixture is lo werth an that of
pure diesel fuel.
While theve hicle is running, component parts
in theex haust system may overheat without
wa rning. #
Neverre fuel using petrol. #
Never mix petrol with diesel fuel. *
N NOOTE
TE Damage caused bythe wrong fuel Ve
hicles with a petrol engine:
Even small amounts of the wrong fuel could
re sult in damage tothe fuel system, the
engine and the emission control system. #
Only refuel using unleaded, sulphu r-free
spar k-ignition engine fuel that conforms 188
188
Driving and parking

Se
Se
tting A
tting A TTENTION ASSI ST
TTENTION ASSIST
Multimedia system:
4 © 5
Settings 5
Assistance
5 Attention Assist
Se
Se tting op
tting op tions
tions #
Select Standard ,Sensitive orOff .
Sugg
Sugg es
esting a rting a r es
est art ar ea
ea #
Select Suggest rest area . #
Activate or deactivate the function.
If AT TENTION ASSIST de tects fatigue or
increasing lack of attention, it suggests a rest
area in the vicinity. #
Select the suggested rest area.
Yo u are guided tothe selected rest area. Cr
Cr
uise contr
uise control and limit ol and limit er
er F
F
unction of cr
unction of cr uise contr
uise controlol
Cruise control regula testh e speed totheva lue
selected bythe driver.
If yo u accelerate toove rtake, forex ample, the
stored speed is not dele ted. If youre mo veyour fo
ot from the accelerator pedal aTer overtaking,
cruise cont rol will resume speed regulation back
to the stored speed.
Yo u can store any speed abo ve20 km/h up tothe
maximum design speed or up tothe set winter
tyre limit.
Obser vethe no tes on driving systems and your
re sponsibility; you may otherwise failto recognise
dangers (/ page 219).
Mer
Mer cedes‑ cedes‑ AMG v
AMG vehicles:
ehicles: cruise cont rol is availa-
ble up toa maximum speed of 250 km/h.
Displ ay
Display s in t
s in the Ins
he Instr trument Display
ument Display
R h (gre y): cruise control is selected but not
yet activated.
R h (gre en): cruise control is active.
A stored speed appears along with theh dis-
pla y.
% The segments extending from the cur rent
stored speed tothe end of the scale, or tothe
set winter tyre limit, light up in the speedome-
te r. Syst Syst
em limits em limits
Cruise control may be unable tomaintain the
stored speed on uphill gradients. The stored
speed is resumed when thegr adient evens out.
Change into a lo werge ar in good time on long and
steep downhill gradients. Take particular no teof
th is when driving a laden vehicle. By doing so, you
will make use of the engine's braking e.ect. This
re lie vesth e load on the brake system and pre-
ve nts the brakes from overheating and wearing
to oqu ickl y.
Do not use cruise control in thefo llowing situa-
tions:
R in tra1c situations which requ ire frequent
ch anges of speed, e.g. in heavy tra1c, on
winding roads
R on slippery roads. Accelerating can cause the
drive wheels tolose traction and theve hicle
could then skid.
R when visibility is poor
F
F unction of t
unction of t he limit
he limiter
er
The limiter restricts the speed of theve hicle. To
re duce the speed tothe set speed, the limiter
applies the brakes automaticall y. Driving and parking
229
229

-
Athttps://be vo.mercedes-benz.com
- Inthe Mercedes-Benz BeVo App
R Ataqu ali/ed specialist workshop *
N
NOOTE
TE Overheating at high outside tempe r-
atures If an inappropriate coolant is used,
the engine
cooling system is not su1ciently pr otected
against overheating and cor rosion at high out-
side temp eratures. #
Only use coolant appr ovedby Mercedes-
Benz. #
Obser vethe inst ructions in the
Mercedes-Benz Speci/cations for Oper-
ating Fluids 320.1. Ha
ve the coolant regula rly re placed at a quali/ed
specialist workshop.
Proportion of antif reeze concentrate in the engine
cooling system:
R A minimum of 50% (antifreeze pr otection down
to about -37°C) R
A maximum of 55% (antif reeze pr otection
down to-45°C) N
No ot
tes on windscr
es on windscr een w
een washer
asher 0uid
0uid Obser
vethe no tes on operating 0uids
(/ page 393). &
W
WARNING
ARNING ‑ Risk of /re and injury due to
windscreen washer concent rate
Wi ndsc reen washer concent rate is highly 0am-
mable. It could ignite if it comes into contact
with hot engine component parts or the
ex haust system. #
Make sure that no windscreen washer
concent rate spills out next tothe /ller
opening. *
N NOOTE
TE Damage totheex terior lighting due
to unsuitable windscreen washer 0uid Unsuitable windscreen
washer 0uids may
damage the plastic sur face of theex terior
lighting. #
Only use windscreen washer 0uids which
are also suitable for use on plastic sur fa-
ces, e.g. MB SummerFit or MB WinterFit. *
N
NOOTE
TE Bloc ked spr aynozzles caused by
mixing windscreen washer 0uids #
Do not mix MB SummerFit and MB Win-
te rFit with other windscreen washer 0u-
ids. Do not use distilled or de-ionised
water. Other-
wise, the /ll le vel sensor may be triggered er rone-
ous ly.
Re commended windscreen washer 0uid:
R abo vefreezing point: e.g. MB SummerFit
R below freezing point: e.g. MB WinterFit
Fo rth e cor rect mixing ratio, referto the informa-
tion on the antifreeze container.
Mix washer 0uid with windscreen washer 0uid all
ye ar round. 402
402
Te
ch nical data

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 194).
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
425 425

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. 436
436
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 #
Depress the brake pedal. #
Engage park position j. #
Consult a quali/ed specialist workshop.
Transmission Malfunction *The transmission is malfunctioning. The cause could be an overheated clutch or bloc kedge ars. #
Let the transmission cool down. #
Ifth e display message still appears following a restart, consult a quali/ed specialist workshop.
d Trans. oil overheated Drive
on with care *T
he transmission is overheating. When the display message is active, start-up and driving characteristics may be tem-
porarily impaired. #
Drive at low engine speed. #
Avoid sporty driving. #
Before pulling away on uphill gradients, let the transmission cool down until the display message disappears.
Parking lock inoperative
Apply the parking brake *T
he transmission is malfunctioning. The park position jcann otbe selected. #
Park theve hicle safel y. #
Use the electric parking brake tosecure theve hicle against rollingaway.
Teaching in transmission
Operate selector lever
Brake for XX seconds Risk
of vehicle rolling *T
he transmission is being taught in. There is a risk of theve hicle rolling away. #
Depress and hold the brake pedal until thete ach-in process has been comple ted.
The electric parking brake is applied automatically during thete ach-in process. #
Switch on theve hicle. 440 440
Displ
aymessages and warning/indicator lamps

Displa
Displa
y messag
y messag es P
es Possible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions #
Select park position j, transmission position kor neutral i.
Risk of vehicle rolling away
Apply parking brake See
Owner's Manual *T
he transmission position cann otbe reliably identi/ed. #
Use the electric parking brake tosecure theve hicle against rollingaway.
Teaching in transmission
complete *T
he transmission's teach-in process is comple te. All transmission positions can be selected again.
Transmission Malfunction
Visit workshop *T
he transmission is malfunctioning.
Consult a quali/ed specialist workshop.
Depress clutch fully to
start engine *Y
ou ha veattem pted tostart theve hicle without depressing the clutch pedal. #
Depress the clutch pedal and then start theve hicle.
*T hevehicle has stalled while theve hicle was pulling away,e.g. because the clutch pedal wasre leased tooqu ickl y. #
Depress the clutch pedal again.
The vehicle will start automaticall y. #
Slowly re leasethe clutch pedal topull away.
Clutch overheated Avoid
pulling away until the warn-
ing goes out *T
he clut chis under considerable load and is overheating.
Av oid frequent pulling away and driving at walking pace over longer distances. #
Stop theve hicle, paying attention toroad and tra1c conditions and lea vetheve hicle running.
The clutch will cool more quickly when theve hicle is running. Display messa
ges and warning/indicator lamps
441 441

W
W
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

Operating.............................................
.287
Displa
Displa y (on-boar
y (on-boar d com
d comput
puter)
er)
Displa yson the inst rument displa y......... 282
Displa
Displa y in t
y in the windscr
he windscr een
een
see Head-up display
Displa
Displa y message
y message
Calling up (on-board computer).............. 409
No tes..................................................... 409
Displa
Displa y messag
y messag es
es
ç - - - km/h.................................... .449
È - - - km/h..................................... 449
h - - - km/h..................................... 448
# 12 V battery See Owner's Man-
ual......................................................... 464
ò Acoustic presence indicator
inoperative............................................ .423
: Active Light System inoperative..... 417
¯ AdBlue system fault Emer. op.:
max. XXX km/h Start not poss. in
XXX km.................................................. 473 ¯
AdBlue system fault Emer gency
op. in XXX miles See Owner's Manual.... 472
¯ AdBlue system fault Engine
start not possible................................... 473
¯ AdBlue system fault See Own-
er's Manual............................................ 472
5 Add 1 litre engine oil when next
re fuelling ............................................... 474
é ATTENTION ASSIST inoperati ve..... 448
é ATTENTION ASSIS T:Take a
break!.................................................... 448
: Automatic driving lights inoper-
ative...................................................... 417
Û Battery overheated Stop, every-
body out! Outdoors if possible ................ 425
û Before starting the engine, turn
th e steering wheel..................................4 32
J Brake immediately ........................ 446
Á Change key batteries .................... 414
è Charger cable connected .............. 423 J
Check brake 0uid le vel.................. 447
ï Check trailer hitch lock (white
display message) .................................... 429
h Check tyre(s) ................................ 467
! Clean the fuel /lter....................... 437
ÿ Coolant Stop vehicle Switch
engine o............................................... 436
! currently una vailable See Own-
er's Manual............................................4 59
÷ currently una vailable See Own-
er's Manual............................................4 60
5 Engine oil le vel cannot be meas-
ured....................................................... 475
5 Engine oil le velRe duce oil le vel..... 474
5 Engine oil le velSt op vehicle
Switch engine o.................................... 474
5 Engine oil pressure Stop Switch
o. engine.............................................. 475
ä Fault Drive at max. 80 km/h ......... 458500 500
Index