2018 MERCEDES-BENZ A-CLASS HATCHBACK check engine

fi
ed based on the actual operating conditions
and/or loads.
Examples of arduous operating conditions:
R regular city driving with frequent intermedi‐
ate stops
R mainly short-dis tance driving
R frequent operation in mountainous terrain or
on poor road sur faces
R when the engine is of ten le ftidling for long
periods
R operation in particula rly dusty conditions
and/or if air-recirculation mode is frequently
used
In these or similar operating conditions, ha vethe
interior air filter, engine air cleaner, engine oil
and oil filter etc. changed more frequent ly. The
ty re s must be checked more frequently if the
ve hicle is operated under increased loads. Fur‐
th er information can be obtained at a qualified
specialist workshop. Battery disconnection periods
The ASS
YST PLUS se rvice inter val display
can only calculate the service due da tewhen
th e bat tery is connected. #
Notedown the service due date displa yed on
th e instrument display before disconnecting
th e battery (→ page419). Engine com
partment Ac
tive bonn et(pedestrian pr otection) Operation of
the active bonnet (pedestrian
pr otection)
In cer tain accident situations, therisk of injury
to pedestrians can be reduced bythe actuation
of the active bonn et. The rear area of the engine
bonn etisraised byappr oximately 70 mm.
Fo rth e drive tothewo rkshop, reset the trig‐
ge red active bonn etyourself. Af terth e active
bonn ethas been triggered, pedestrian pr otection
may be limited.
A qu alified specialist workshop must re-ins tate
th e full functionality of the active bonn et. The active bonnet is not
available in all coun‐
tries.
Re setting the active bonnet &
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: 420
Maintenance and care

#
Push yellow handle 1onthe bonn etcatch
to the left as far as it will go (palm down‐
wa rds). Lift the bonn etuntil it is automati‐
cally raised bythe pneumatic stru t. #
Toclose: lowe rth e bonn etand let it fall from
a height of appr oximately 20 cm. #
Ifth e bonn etcan still be lif ted slightl y,open
th e bonn etagain and close it with a little
fo rc e until it engages cor rectl y. Engine oil
Checking
the engine oil le vel using the on-
board compu ter
Re quirements:
The engine oil le vel is de term ined during driving.
De term ining the engine oil le vel can take up to
30 minutes with a normal driving style and even
longer with an active driving style.
In order torecei veare sult as quickly as possi‐
ble:
R warm upthe engine
R park theve hicle on a le vel sur face
R leave the engine running at idling speed
On-board compu ter:
, Assistance .
Engine oil level
Yo u will see one of thefo llowing messages on
th e multifunction display:
R Engine oil level Measuring now : measure‐
ment of the oil le vel is not yet possible. #
Repeat there qu est af ter a maximum of
30 minutes driving. R
Engine oil level OK andthe bar display for
indicating the oil le vel on the multifunction
display is green and is between "min" and
"max": the oil le vel is cor rect.
R Engine oil level Add 1,0 l andthe bar display
fo r indicating the oil le vel on the multifunc‐
tion display is orange and is below "min": #
Top up with 1 l engine oil.
R Reduce engine oil level andthe bar display
fo r indicating the oil le vel on the multifunc‐
tion display is orange and is abo ve"max": #
Drain off excess engine oil that has been
added. Consult a qualified specialist work‐
shop.
R For engine oil level turn on ignition: #
switch on the ignition tocheck the engine oil
le ve l.
R Engine oil level System inoperative : sensor
fa ulty or not inser ted. #
Consult a qualified specialist workshop.
R Engine oil level System currently unavail. : Maintenance and care
423

#
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