engine MERCEDES-BENZ A-CLASS SALOON 2018 Repair Manual

#
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:
4 Service 5
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
433

#
close the bonn et.
To pping up engine oil &
WARNING Risk of bu rns from hot com‐
ponent parts in the engine compartment
Cer tain components in the engine compart‐
ment can be very hot, e.g. the engine, the
ra diator and parts of theex haust sy stem. #
Allow the engine tocool down and only
to uch co mponent parts described in the
fo llowing. &
WARNING Risk offire and injury from
engine oil
If engine oil comes into con tact wi thhot
component parts in the engine compart‐
ment, it may ignite. #
Make sure that no engine oil is spilled
next tothefiller opening. #
Allow the engine tocool off and thor‐
oughly clean the engine oil from compo‐
nent parts before starting theve hicle. *
NO
TEEngine dama gecaused byan
incor rect oil filter, incor rect oil or addi‐
tives #
Do not use engine oils or oil filters
which do not cor respond tothe specifi‐
cations explicitly prescribed forthe
service inter vals. #
Do not alter the engine oil or oil filter in
order toachie velonger change inter vals
th an presc ribed. #
Do not use additives. #
Follow the instructions in the service
inter val display rega rding the oil
ch ange. *
NO
TEDama gecaused bytopping up too
much engine oil To
o much engine oil can damage the engine
or the catalytic con verter. #
Have excess engine oil remo ved at a
qu alified specialist workshop. #
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 433).434
Maintenance and care

Checking
the coolant le vel &
WARNING Risk of bu rns from hot com‐
ponent parts in the engine compartment
Cer tain components in the engine compart‐
ment can be very hot, e.g. the engine, the
ra diator and parts of theex haust sy stem. #
Allow the engine tocool down and only
to uch co mponent parts described in the
fo llowing. &
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 torelease
ove rpressure. #
Continue turning cap 1anti-clockwise and
re mo veit.
The coolant le vel is cor rect in thefo llowing
cases:
R ifth e engine is cold, the coolant is up to
mar ker bar 2.
R ifth e engine is warm,th e coolant is up to
1. 5 cm overth e mar ker bar 2. #
If necessar y,top up with coolant that has
been appr ovedfo r Mercedes-Benz.
R Further information on coolant
(/ page 503). To
pping up the windsc reen washer sy stem &
WARNING Risk of bu rns from hot com‐
ponent parts in the engine compartment
Cer tain components in the engine compart‐
ment can be very hot, e.g. the engine, the
ra diator and parts of theex haust sy stem. Maintenance and care
435

#
Allow the engine tocool down and only
to uch co mponent parts described in the
fo llowing. &
WARNING Danger of bu rns when open‐
ing the bonn et
If yo u open the engine bonn etwhen the
engine has overheated or during a fire inthe
engine compartment, you could come into
contact with hot gases or other escaping
operating fluids. #
Before opening the bonn et, allow the
engine tocool down. #
Intheeve nt of a fire inthe engine com‐
partment, keep the engine bonn et
closed and call thefire service. &
WARNING ‑ Risk of fire and injury due to
windscreen washer concentrate
Wi ndsc reen washer concentrate is highly
fl ammable. It could ignite if it comes into
con tact wi thhot engine component parts or
th eex haust sy stem. #
Make sure that no windsc reen washer
concentrate spills out next tothefiller
opening. #
Remo vethe cap 1bytheta b. #
Top up thewa sher fluid. Ke
eping the air-water duct free #
Keep the area between the bonn etand the
windscreen free of deposits, e.g. ice, sn ow
and lea ves. Cleaning and care
Information on
washing theve hicle in a car
wa sh &
WARNING Risk of an accident due to
re duced braking po wer af terwa shing the
ve hicle
Braking ef ficiency is reduced af terwa shing
th eve hicle. #
Afterth eve hicle has been washed,
brake carefully while paying attention to
th e traf fic conditions until braking
po we r has been fully restored. 436
Maintenance and care

Ke
ep children away. Obser
vethis Owner's Manual.
If yo u do not intend touse theve hicle over an
ex tended pe riod of time:
R activate standby mode, or
R connect the battery toa bat tery charger
appr oved byMercedes-Benz, or
R consult a qualified specialist workshop to
disconnect the battery Note
s onstarting assi stance and on charg‐
ing the12 V battery When
charging the battery and during starting
assis tance, al ways use the jump-s tart connec‐
tion point in the engine compartment. *
NO
TEDamaging the battery thro ugh
ove rvoltage When using a battery
charge r without a maxi‐
mum charging voltage, the battery or the
ve hicle electronics may be damaged. #
Only use battery charge rs with a maxi‐
mum charging voltage of 14.8 V. &
WARNING Risk ofexplosion from hydro‐
ge nga s igniting
A battery generates hydrogen gas during the
ch arging process. If there is a short circuit or
spar ksstart toform ,th ere is a danger of the
hy drogen gas igniting. #
Make sure that the positive term inal of
th e connected battery does not come
into conta ct withvehicle parts. #
Never place me tal objects or tools on a
batter y. #
When connecting and disconnecting the
batter y,yo u must obse rveth e descri‐
bed order forth e battery clamps. #
When giving starting assis tance, al ways
make sure that you on lyconnect bat‐
te ry term inals with identical polarity. #
During starting assis tance, you must
obse rveth e described order for con‐
necting and disconnecting the jump
lead. #
Do not connect or disconnect the bat‐
te ry cla mp s while the engine is running. &
WARNING Risk ofexplosion during
ch arging process and starting assis tance
During thech arging process and starting
assis tance, the battery may release an explo‐
sive gas mixture. #
Avoid fire , naked flames, creating
spar ksand smoking. #
Make sure that there is suf ficient venti‐
lation du ring thech arging process and
during starting assis tance. #
Do not lean over a batter y. Breakdown assis
tance 457

&
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 be pe rformed using
only batteries with a nominal voltage of 12V.
R The vehicles must not touch.
R Petrol engine: only acceptstarting assis‐
ta nce if the engine and exhaust sy stem are
cold. 458
Breakdown assis tance

St
arting assi stance and charging the12 V
battery Re
quirements:
R The vehicle is secured with the electric park‐
ing brake.
R Automatic transmission: the transmission
is in position j.
R Manual transmission: the transmission is in
neutral.
R The ignition and all electrical consumers are
switched off.
R The bonn etis open. #
Slide co ver1 of positive clamp 2onthe
jump-s tarting connection point in the direc‐
tion of the ar row. #
Connect positive clamp 2onyour vehicle to
th e positive pole of the donor battery using
th e jump lead/charging cable. Alw ays begin
with positive clamp 2onyour ow nve hicle
fi rs t. #
During starting assi stance: start the
engine of the donor vehicle and run at idle
speed. #
Connect the negative pole of the donor bat‐
te ry and ear thpoint 3ofyour ow nve hicle
by using the jump lead/charging cable. Begin
with the donor battery firs t. #
During starting assi stance: start the
engine of your ow nve hicle. #
During thech arging process: start the
ch arging process. #
During starting assi stance: letthe engines
ru nfo r se veral minutes. #
During starting assi stance: before discon‐
necting the jump lead, switch on an electrical
consumer in your ow nve hicle, e.g. there ar
wind owheater or lighting.
When thest arting assis tance/charging process
is compl ete: #
First,re mo vethe jump lead/charging cable
from ear thpoint 3and negative pole of the
donor batter y,then from positive clamp 2
and positive pole of the donor batter y.Begin Breakdown assis
tance 459

Pe
rm itted towing me thods Ve
hicle equipment/ towing
me thod Bo
th axles on thegr ound Fr
ont axle raised Re
ar axle raised
Ve hicles with manual transmission Yes, maximum 50 km at 50 km/h Yes, maximum 50 km at 50 km/h Yes, maximum 50 km at 50 km/h
Ve hicles with automatic transmis‐
sion Ye
s, maximum 50 km at 50 km/h Yes, maximum 50 km at 50 km/h Yes, maximum 50 km at 50 km/h
4MATIC vehicles Yes, maximum 50 km at 50 km/h No NoTo
wing with a raised axle: towing should be
per form ed byato wing compan y. To
wing theve hicle with bo thaxles on the
gr ound #
Obser vethe no tes on the permitted towing
me thods (/ page 460). #
Make sure that the battery is connected and
ch arge d. Obser
vethefo llowing points when the battery is
dischar ged:
R the engine cann otbe star ted
R the electric parking brake cann otbe released
or applied
R vehicles with automatic transmission: the
automatic transmission cannot be shif tedto
position iorj. %
Vehicles with automatic transmission: if
th e automatic transmission cann otbe shif‐
te dto position i, orthe multifunction dis‐
play in the instrument clus ter does not show
anything, ha vetheve hicle transpor tedaw ay
( / page 463). A towing vehicle with lift‐
ing equipment is requ ired forve hicle trans‐
por tation. Breakdown assi
stance 461

*
NO
TEDama getothe driv etra in due to
incor rect positioning #
Do not position theve hicle abo vethe
connection point of the transport vehi‐
cle. To
wing eyesto rage location The
towing eye1 is located in thestow age
space under the boot floor. Installing
theto wing eye #
Press the mark on co ver1 inwa rds and
re mo ve. #
Screw intheto wing eyeclockwise as far as it
will go and tighten.
Ve hicles with a trailer hitch: vehicles with a
trailer hitch do not ha veare ar brac ketfo rthe to
wing eye. Fasten theto w bar tothe trailer
hitch.
% Make sure that co ver1 engages in the
bumper when youre mo vetheto wing eye.
* NO
TEDama gedue toincor rect use of
th eto wing eye When a
towing eye is used toreco ver a vehi‐
cle, theve hicle may be damaged in the proc‐
ess. #
Only use theto wing eyeto to waw ay or
to w start theve hicle. To
w starting theve hicle (eme rgency engine
st art) Ve
hicles with automatic transmission
* NO
TEDama getothe automatic trans‐
mission due to tow-starting The automatic transmission may be damaged
in the process of tow- starting vehicles with
automatic transmission. 464
Breakdown assis tance

#
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 461). #
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 466).
* 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. Breakdown assis
tance 465