check engine MERCEDES-BENZ A-CLASS HATCHBACK 2018 User Guide

#
Turn cap 1anti-clockwise and remo veit. #
Top up the engine oil. #
Replace cap 1and turn it clockwise as far
as it will go. #
Check the oil le vel again (→ page 423). Checking
the coolant le vel &
WARNING Danger of bu rns from hot
component parts in the engine compart‐
ment
Cer tain component parts in the engine com‐
partment may be very hot, e.g. the engine,
th era diator and parts of theex haust sy stem. #
Let the engine cool down and only
to uch the component parts described
below: &
WARNING Risk of scalding from hot
coolant
The engine cooling sy stem is pressurised,
particularly when the engine is warm. If you
open the cap, you could be scalded byhot
coolant spr aying out. #
Let the engine cool down before open‐
ing the cap. #
When opening the cap, wear pr otective
gl ove s and saf etygl asses. #
Open the cap slowly torelease pres‐
sure. #
Park theve hicle on a le vel sur face. #
Check the coolant temp erature display in the
instrument clus ter.
The coolant temp erature must be below
70 °C. #
Slowly turn cap 1anti-clockwise torelie ve
ov erpressure. Maintenance and care
425

&
WARNING Risk ofexplosion from a fro‐
zen battery
A dischar ged battery may freeze at temp era‐
tures slightly abo veor below freezing point.
During starting assis tance or battery charg‐
ing, bat tery gas may be released. #
Alw aysth aw a frozen bat tery out first
before charging it or per form ing start‐
ing assis tance. If
th e indicator/warning lamps in the instrument
clus ter do not light up at low temp eratures, it is
ve ry likely that the dischar ged battery has fro‐
zen. In this case you may neither jump-s tart the
ve hicle nor charge the batter y.
The service life of a battery that has been
th awe d may be dramatically shor tened. The
st arting characteristics may be impaired, espe‐
cially at low temp eratures.
It is recommended that you ha veathaw ed bat‐
te ry checked at a qualified specialist workshop. *
NO
TEDama gecaused bynumerous or
ex tended attem ptsto start the engine Nume
rous or extended attem ptsto start the
engine may damage the catalytic con verter
due tonon-combu sted fuel. #
Avoid numerous and extended attem pts
to start the engine. Obser
vethefo llowing points during starting
assis tance and when charging the battery:
R Only use undamaged jump lead/charging
cables with a suf ficient cross-section and
insula tedte rm inal clamps.
R Non- insulated parts of thete rm inal clamps
must not come into con tact wi thother me tal
parts while the jump lead/charging cable is
connected tothe battery/jump-s tart connec‐
tion point.
R The jump lead/charging cable must not
come into contact wi thany parts which may
mo vewhen the engine is running.
R Alw ays make sure that nei ther you nor the
battery is elect rostatically charge d. R
Keep away from fire and naked flames.
R Do not lean overth e batter y.
Obser vethe additional following points when
ch arging the battery:
R Only use battery charge rs tested and
appr oved for Mercedes-Benz.
R Read the battery charge r's operating instruc‐
tions before charging the batter y.
Obser vethe additional following points during
st arting assis tance:
R Starting assis tance may only be pr ovided
using batteries with a nominal voltage of 12
V.
R The vehicles must not touch.
R Petrol engine: only acceptstarting assis‐
ta nce if the engine and exhaust sy stem are
cold. Breakdown assis
tance 447

#
Vehicles with automatic transmission
must not be tow- star ted. #
Vehicles with automatic transmission must
not be tow- star ted.
Ve hicles with manual transmission #
Obser vethe no tes on towing away
( → page 450). #
If necessar y,allow the engine and exhaust
sy stem tocool down. #
Switch the ignition on. #
Enga gesecond gear. #
Release the electric parking brake. #
Tow- start theve hicle while the clutch pedal
is fully depressed. #
Slowly release the clutch pedal. #
Immediately shift toneutral if the engine
st arts. #
Pull over and stop theve hicle, paying atten‐
tion toroad and traf fic conditions. #
Remo vetheto w bar. #
Remo vetheto wing eye. #
Have theve hicle checked at a qualified spe‐
cialist workshop. Electrical fuses
Note
s on electrical fuses &
WARNING Risk of accident and inju ry
due to ov erloaded lines
If yo u manipulate or bridge a faulty fuse or if
yo ure place it with a fuse with a higher
amperage, the electric line could be overloa‐
ded.
This could result in a fire. #
Alw aysre place faulty fuses with speci‐
fi ed new fuses conta iningthe cor rect
amperage. *
NO
TEDama gedue toincor rect fuses Electrical components or sy
stems may be
damaged byincor rect fuses, or their func‐
tionality may be significant lyimpaired. #
Only use fuses that ha vebeen appr oved
by Mercedes-Benz and which ha vethe
cor rect fuse rating. Blown fuses mu
stbe replaced with fuses of the
same rating, which you can recognise bythe col‐
our and fuse rating. The fuse ratings and fu rther
information tobe obser ved are lis ted in the fuse
assignment diagram.
Fu se assignment diag ram: onthe fuse box in
th e engine compartment (→ page 455).
* NO
TEDama geor malfunctions caused
by moisture Moisture may cause dama
getothe electrical
sy stem or cause it tomalfunction. #
When the fuse box is open, make sure
th at no moisture can enter the fuse
box. #
When closing the fuse box, make sure
th at the seal of the lid is positioned cor‐
re ctly on the fuse box. 454
Breakdown assis tance

*
NO
TEMalfunctions due tothe dilution of
Ad Blue ®
or the use of additive-enhanced
Ad Blue ® The function of
the NOx exhaust gas af ter‐
treatment can be impaire dby the use of
unsuitable denoxification agents. #
Only use AdBlue ®
in accordance wi th
ISO 222 41 . #
Do not dilu teAd Blue ®
wi th wate r. #
Do not use additive-enhanced AdBlue ®
. *
NO
TEDama geand malfunctions due to
impurities in AdBlue ® Consequences of impu
rities in AdBlue ®
:
R increased emission values
R damage tothe catalytic con verter
R NOx exhaust gas af tertre atment malfunc‐
tions #
Avoid impurities in AdBlue ®
. Ad
Blue ®
re sidues cr ystallise af ter a period of
time, and contamina tethe sur faces wi thwhich
th ey come into contact. Clean the dirty sur faces
wi th wate r as soon as possible.
When you open theAd Blue ®
tan k,small
amounts of ammonia vapour may escape. Do
not inhale any ammonia vapours that may be
re leased. Only fill th eAd Blue ®
tank in well-venti‐
lated areas.
Ad Blue ®
filling capacity and consum ption
To tal capacity of AdBlue ®
tank Mode
lT otal capacity
All models 23.8 l Ad
Blue ®
consu mption
Like fuel consu mption, AdBlue ®
consu mption is
highly dependent upon driving style and operat‐
ing conditions. Forth is reason, your vehicle's
actual consum ption figures under normal operat‐
ing conditions may dif fer from the consum ption
fi gures calculated. AdBlue ®
consu mption is
between 1 % and 5 % of fuel consumption. Ha veth
eAd Blue ®
supply checked at a qualified spe‐
cialist workshop before making journe ysoutside
of Europe. Before a longer stay outside of
Europe, consult a qualified specialist workshop.
Display theAd Blue ®
ra nge and le vel
( → page 254). Engine oil
Note
s on engine oil
Obser vethe no tes on operating fluids
(→ page 485). 490
Tech nical da ta

Display messages
Possible causes/consequences and M
MSolutions
Stop vehicle Leave engine
running #
Lea vethe engine running. #
Wait until the display message disappears before pulling away.
4 Engine oil level Reduce oil
level *D
isplay message only for cer tain engines:
The engine oil le vel is too high.
* NO
TEEngine dama gecaused bydriving with excess engine oil #
Avoid long journe yswith excess engine oil. #
Consult a qualified specialist workshop immediately and ha vethe engine oil siphoned off.
4 Engine oil level Stop vehi-
cle Switch engine off *D
isplay message only for cer tain engines:
The engine oil le vel is too lo w.
* NO
TEEngine dama gecaused bydriving with insuf ficient engine oil #
Avoid long journe yswith insuf ficient engine oil. #
Pull over and stop theve hicle safely as soon as possible, paying attention toroad and traf fic conditions. Do not
continue driving under any circums tances. #
Switch off the engine. #
Add 1 l engine oil. #
Check the engine oil le vel. Display messages and
warning/indicator lamps 523

Display messages
Possible causes/consequences and M
MSolutions
AdBlue system fault Engine
start not possible Ty
res Display messages
Possible causes/consequences and M MSolutions
Tyre pressure Check tyres *T
he tyre pressure loss warning sy stem has de tected a significant loss in pressure. &
WARNING Risk of an accident due toinsuf ficient tyre pressure
Ty res with insuf ficient tyre pressure pose thefo llowing risks:
R The tyres may bur st, especially as the load and vehicle speed increase.
R The tyres may wearexc essively and/or une venly, which may greatly impair tyre traction.
R ‑ The driving characteristics, steering and braking may be greatly impaired.
Yo u could then lose control of theve hicle. #
Obser vethere commended tyre pressures. #
Adjust the tyre pressure if necessar y. #
Stop theve hicle, paying attention toroad and traf fic conditions. #
Check the tyre pressure (→ page 459) andthe tyres. #
When the tyre pressure is cor rect, restart the tyre pressure loss warning sy stem (→ page 467). 528
Display messages and warning/indicator lamps

Display messages
Possible causes/consequences and M
MSolutions #
Depress the clutch pedal again.
The engine starts automaticall y. #
Slowly release the clutch pedal topull away.
N permanently active Risk
of vehicle rolling *
While theve hicle is rolling or while you are driving, the transmission has been shif tedto position i. #
Depress the brake pedal tostop and, when theve hicle is stationar y,shift the transmission toposition j. #
Tocontinue your journe y,shift the transmission toposition hork.
Risk of vehicle rolling away
Apply parking brake See
Owner's Manual *T
he transmission position cannot be identified securel y. #
Use the electric parking brake tosecure theve hicle against rolling away.
ï
Check trailer hitch lock
(white displ aymessa ge) *T
he trailer tow hit chis not operational when you are driving with a trailer. #
Stop theve hicle immediately, paying attention toroad and traf fic conditions, and switch off the engine. #
Uncouple the trailer and secure it against rolling away. #
Initiate a new swivelling procedure (→ page242). #
Ifth e ball neck is extended, press and hold the button on theta ilgate until the ball neck engages beneath the
bumper. #
When the display message disappears, couple up the trailer and drive on. &
WARNING Risk of an accident if the ball neck is not loc ked
If th e ball neck is not in the loc ked position, the trailer may come loose. Display messages and
warning/indicator lamps 539

Wa
rning/indicator lamp
Possible causes/consequences and M
MSolutions #
Do not top up the brake fluid. #
Pull over and stop theve hicle safely as soon as possible, paying attention toroad and traf fic conditions. Do not
continue driving under any circums tances. #
Obser vethe messages on the multifunction displa y. #
Consult a qualified specialist workshop.
! ABS warning lamp The
yellow ABS warning lamp is lit while the engine is running.
ABS is malfunctioning.
If th ere is an additional warning tone, EBD is malfunctioning.
Other driving sy stems and driving saf ety sy stems may also be malfunctioning. &
WARNING Thereisrisk of skidding if EBD or ABS is malfunctioning
If EBD or ABS is malfunctioning, the wheels could lock when braking
The steering capability and braking characteristics are thus se verely impaired. The braking dis tance may increase in
an emergency braking situation. In addition, other driving saf ety sy stems are switched off. #
Drive on carefull y. #
Have the brake sy stem checked immediately at a qualified specialist workshop. #
Drive on carefully. #
Obser vethe messages on the multifunction displa y.550
Display messages and warning/indicator lamps

Wa
rning/indicator lamp
Possible causes/consequences and M
MSolutions #
Consult a qualified specialist workshop.
! Re d indicator lamp, elect ric
parking brake applied
!
Ye llow elect ric pa rking
brake indicator lamp is mal‐
functioning The
red elect ric pa rking brake indicator lamp flashes or is lit. The yellow indicator lamp is also lit if the electric parking
brake malfunctions. #
Obser vethe messages on the multifunction displa y.
J
Brake sy stem warning lamp
(yellow) The
yellow brake sy stem warning lamp is lit while the engine is running. &
WARNING Risk of an accident due toa brake sy stem malfunction
If th e brake sy stem is malfunctioning, braking characteristics may be impaired. #
Drive on carefull y. #
Have the brake sy stem checked immediately at a qualified specialist workshop. #
Adjust your speed and continue todrive carefull y,leaving a suitable dis tance totheve hicle in front. #
Ifth e multifunction display sho wsa display message, please obse rveth is. Display messages and
warning/indicator lamps 551

Wa
rning/indicator lamp
Possible causes/consequences and M
MSolutions
å ESP ®
OFF warning lamp The
yellow ESP ®
OFF warning lamp is lit while the engine is running.
ESP ®
is deacti vated. &
WARNING Risk of skidding when driving wi thESP ®
deacti vated
If ESP ®
is deactivated, ESP ®
cannot car ryout vehicle stabilisation. The availability of fur ther driving saf ety sy stems
is also limited. #
Drive on carefull y. #
Only deactivate ESP ®
for as long as the situation requ ires.
If ESP ®
cannot be activated, ESP ®
is malfunctioning. #
Have ESP ®
ch ecked immediately at a qualified specialist workshop. #
Obser vethe no tes on deactivating ESP ®
(→ page 186).
6 Re stra int sy stem warning
lamp The
redre stra int sy stem warning lamp is lit while the engine is running.
The restra int sy stem is faulty (→ page 30). &
WARNING Risk of inju ryor fata l injury due toa malfunction in there stra int sy stem
If th ere stra int sy stem is malfunctioning, restra int sy stem components may be triggered unintentionally or might not
be triggered at all in theeve nt of an accident. This may af fect the seat belt tensioner or airbag, forex ample. #
Have there stra int sy stem checked and repaired immediately at a qualified specialist workshop. Display messages and
warning/indicator lamps 553