engine MERCEDES-BENZ S-CLASS SALOON LONG 2021 Repair Manual

&
W
WARNI NG
ARNI NGRisk of explosion due toexplo-
sive mixture of gases
An explosive mixture of gases can escape
from the battery during charging and starting
assis tance. #
Fire , naked 0ames, smoking and creating
spar ksmust be avoided. #
Make sure there is adequate ventilation. #
Do not stand overth e batter y. &
W
WARNI NG
ARNI NGRisk of explosion from a frozen
battery
A dischar ged battery may freeze at temp era-
tures slightly abo veor below freezing point.
During starting assistance or battery charging,
battery gas can be released. #
Always allow a battery tothaw before
ch arging it or per form ing starting assis-
ta nce. If
th e indicator/warning lamps in the inst rument
cluster do not light up at low temp eratures, it is
ve ry likely that the dischar ged battery has frozen. In
this case you may neither jump-start theve hi-
cle nor charge the batter y.
The service life of a bat tery that has been thawed
may be dramatically shor tened. The starting char-
acteristics may be impaired, especially at low
te mp eratures.
It is recommended that you ha veath awe d battery
ch ecked at a quali/ed specialist workshop.
Plug-in h Plug-in h ybr
ybrid
id
If yo ur vehicle has been star ted with starting
assistance, it may not be possible touse the elec-
tric drive for appr oximately 30 minutes.
St arting assis tance is not considered tobe a nor-
mal operating condition.
All v All v ehicles
ehicles
* NO
NOTE
TEDamage caused bynume rous or
ex tended attem ptsto start the engine Numerous or
extended attem ptsto start the
engine may damage the catalytic con verter
due tonon-combusted fuel. #
Avoid numerous and extended attem pts
to start the engine. Obser
vethefo llowing points during starting assis-
ta nce and when charging the batter y:
R Only use undamaged jump lead/charging
cables with a su1cient cross-section and
insulated term inal clamps.
R Non-insulated parts of thete rm inal clamps
must not come into contact with other me tal
parts while the jump lead/charging cable is
connected tothe battery/jump-start connec-
tion point.
R The jump lead/charging cable must not come
into contact with any parts which may mo ve
when the engine is running.
R Always make sure that nei ther you nor the bat-
te ry is electros tatically charge d.
R Keep awa y from /re and naked 0ames.
R Do not lean overth e batter y. Breakdow
n assistance
447 447

Obser
vethe additional following points when
ch arging the batter y:
R Only use battery charge rs tested and
appro vedfo r Mercedes-Benz.
R Read the battery charge r's operating inst ruc-
tions before charging the batter y.
Obser vethe additional following points during
starting assistance:
R Starting assis tance may only be pr ovided
using vehicles, batteries or other jump start
devices with a nominal voltage of 12 V.
R The vehicles must not touch.
R V
Vehicles wit
ehicles wit h a pe
h a petr
trol engine:
ol engine: jump-start the
ve hicle only when the engine and exhaust sys-
te m are cold. S
S
t
tar
ar ting assist
ting assist ance and c
ance and c har
harging t
ging t he 12 V batt
he 12 V batt ery
ery Pr
Pr
epar
epar ing f
ing for st
or st ar
arting assist
ting assist ance/t
ance/the c
he char
harging
ging
pr
pr ocess
ocess #
Secure theve hicle byapplying the electric
parking brake. #
ShiT the transmission toposition j. #
Switch o. theve hicle and all elect rical con-
sumers. #
Open the bonnet. #
Open co ver1. #
Slide pr otective co ver2 of POSITIVE contact
3 onthe jump-start connection point in the
direction of the ar row. S
S
t
tar
ar ting assist
ting assist ance
ance #
Connect the POSITIVE contacts of theve hi-
cles with the jump lead. Start with your own
ve hicle /rst. #
Start the engine of the donor vehicle and run
it at idling speed. #
Connect the negative term inal of the donor
battery toear thpoint of your vehicle 4using 448
448
Breakdown assis
tance

th
e jump lead. Start with the donor vehicle
/rst. #
Start the engine of your ow nve hicle. #
Let the engines runfo r se veral minutes. #
Before disconnecting the jump leads, switch
on an electrical consumer in your ow nve hicle,
e.g. there ar wind owheater or the lighting.
When starting assistance has /nished: #
Firs t, re mo vethe jump lead from the ear th
point of your ow nve hicle and the negative ter-
minal of the donor batter y,then remo vethe
jump lead from the POSITIVE contacts of bo th
ve hicles. Alw ays start with your ow nve hicle
/rst. #
Close pr otective co ver2 of POSITIVE con-
ta ct 3 and close co ver1.
Plug-in h
Plug-in h ybr
ybrid:
id:ifyo ur vehicle has been star ted
with starting assis tance, it may not be possible to
use the electric drive for appr oximately 30
minutes.
Fu rther information can be obtained at a quali/ed
specialist workshop. Char Char
ging t
ging t he 12 V batt
he 12 V batt ery
ery #
Connect the POSITIVE contacts of theve hicle
and thech arge r with thech arging cable. Start
with theve hicle /rst. #
Connect the NEG ATIVE contact of thech arger
and ear thpoint 4ontheve hicle with the
ch arging cable. Start with thech arge r /rst. #
Start thech arging process.
When thech arging process is comple te: #
Remo vethech arging cable from ear thpoint
4 ontheve hicle and the NEG ATIVE contact
of thech arge r /rst and then from the POSI-
TIVE contacts on theve hicle and charge r.
Alw ays start with theve hicle /r st. #
Close pr otective co ver2 of POSITIVE con-
ta ct 3 and close co ver1. R
R
eplacing t
eplacing t he 12 V batt
he 12 V batt ery
ery #
Obser vethe no tes on the 12 V battery
(/ page 444). Mercedes-Benz
recommends that you ha vethe
12 V battery replaced at a quali/ed specialist
wo rkshop, e.g. at a Mercedes-Benz Se rvice
Centre.
Obser vethefo llowing no tes if youwa nttoreplace
th e battery yourself:
R Alwaysre place a faulty battery with a battery
which meets the speci/c vehicle requ ire-
ments.
The vehicle is equipped with an AGMtech nol-
ogy bat tery (Absorbent Glass Mat) or a lith-
ium-ion batter y.Fu llve hicle functionality is
only guaranteed with an AGM bat tery or lith-
ium-ion batter y.Fo r saf etyre asons, Mercedes-
Benz recommends that you only use batteries
which ha vebeen tested and appro vedfo ryo ur
ve hicle byMercedes-Benz.
R Carryove r de tach able parts, such as vent
hoses, elbow /ttings or term inal co vers from
th e battery being replaced.
R Make sure that theve nt hose is alw ays con-
nected tothe original opening on the side of
th e batter y.
Fi t any existing or supplied cell caps. Breakdown assistance
449 449

T
T
o
o wing ey
wing eye st
e st or
orag
ag e location
e location To
wing eye1 is located under the boot 0oor.
Depending on theve hicle equipment, theto wing
ey e may be located at ano ther position in the
boot. F
F
itting and r
itting and r emo
emoving t
ving t heto
he towing eye
wing eye #
Press the mark on co ver1 inwa rds and
re mo ve. #
Screw intheto wing eye clockwise as far as it
will go and tighten.
V
V ehicles wit
ehicles wit h a tr
h a trailer hitc
ailer hitc h:
h:vehicles with a trailer
hitch do not ha veare ar brac ketfo rth eto wing
ey e. Fasten theto w bar tothe trailer hitch. #
Make sure that co ver1 engages in the
bumper when youre mo vetheto wing eye.
* N
NOOTE
TE Damage totheve hicle due toincor-
re ct use of theto wing eye or trailer hitch When a
towing eye or trailer hitch is used to
re co ver a vehicle, theve hicle may be damaged
in the process. #
Only use theto wing eye or trailer hitch to
to w awa y or tow start theve hicle. #
Do not use theto wing eye or trailer hitch
to to wtheve hicle during reco very. T
T
o
o w
w -st
-st ar
arting t
ting t he v
he vehicle (emerg
ehicle (emerg ency engine st
ency engine st ar
art)
t) *
N
NOOTE
TE Damage tothe automatic transmis-
sion due to tow-starting To
w- starting theve hicle can damage the auto-
matic transmission. #
Do not tow- start theve hicle. #
Do not tow- start theve hicle. 456
456
Breakdown assis
tance

Electr
Electr
ical fuses
ical fuses N
No
ot
tes on electr
es on electr ical fuses
ical fuses &
W
WARNING
ARNING Risk of accident and injury due
to ove rloaded lines
If yo u manipulate or bridge a faulty fuse or if
yo ure place it with a fuse with a higher amper-
age, the electric line could be overloaded.
This could result in a /re. #
Alwaysre place faulty fuses with speci-
/ed new fuses containing the cor rect
amperage. *
N
NOOTE
TE Damage due toincor rect fuses Electrical components or systems may be
damaged
byincor rect fuses, or their function-
ality may be signi/cantly impaired. #
Only use fuses that ha vebeen appr oved
by Mercedes-Benz and which ha vethe
cor rect fuse rating. Blown fuses must be
replaced with fuses of the
same rating, which you can recognise bythe col- our and fuse
rating. The fuse ratings and fur ther
information tobe obser ved can be found in the
fuse assignment dia gram.
F F use assignment diagr
use assignment diagr am:
am:intheve hicle docu-
ment wallet.
* NO
NOTE
TEDamage or malfunctions caused by
moisture Moisture may cause damage
tothe electrical
system 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. If
th e ne wlyinser ted fuse also blo ws, ha vethe
cause traced and recti/ed at a quali/ed specialist
wo rkshop.
Ensure thefo llowing before replacing a fuse:
R The vehicle is secured against rolling away.
R All electrical consume rsare switched o..
R The vehicle is switched o.. The elect
rical fuses are located in thefo llowing
fuse bo xes:
R Fuse box in the engine compartment on the
driver's side (/ page 457)
R Fuse box on the driver's side of the cockpit
(/ page 459)
R Fuse box in the front passenger foot we ll
(/ page 460)
R Fuse box in the boot on theright-hand side of
th eve hicle, when vie wed in the direction of
tr av el (/ page 460) Opening and closing t
Opening and closing t
he fuse bo
he fuse box in t
x in the engine
he engine
com
com par
partment
tment R
R
eq
equir uir ements:
ements:
R Obser vethe no tes on elect rical fuses
(/ page 457).
R Have thefo llowing tools readily available:
- a dry clo th
- a scr ewdriver with an appropriate head Breakdown assistance
457
457

Opening
Opening
%
Depending on theve hicle equipment, access
to the fuse box may be limited. Mercedes-
Benz recommends consulting a quali/ed spe-
cialist workshop, e.g. a Mercedes-Benz
Se rvice Centre. &
W WARNING
ARNING Risk of injury from using the
windscreen wipers when the bonnet is
open
If th e windscreen wipers start moving when
th e bonnet is open, you could be trapped by
th e wiper linkage. #
Always switch o. the windscreen wipers
and vehicle before opening the engine
bonnet. #
Release thero tary catches on co ver1 and
pull the co ver up and out. #
Remo veany existing moisture from the fuse
box using a dry clo th. #
Depending on theve hicle equipment, there
may be an electrical component 2onthe
fuse box lid. If present, unscrew screw 3 and
put the component tothe side without discon-
necting the electrical connection. #
If present, release hoses 4from thereta ining
clips on the fuse box and vehicle body. 458
458
Breakdown assis
tance

#
If present, release hoses 5from thereta ining
clips in the engine compartment and vehicle
body. #
Unscr ewscrews6 and fold out bar 7. #
Unscr ewscrews8 and remo vefuse box lid
9 tothe side.
Closing
Closing #
Check whe ther the seal is positioned cor rectly
in lid 9. #
Place lid 9onthe fuse box and tighten
scr ews8. #
Fold back bar 7and tighten scr ews6. #
If present, engage hoses 5inthere taining
clips in the engine compartment and vehicle
body. #
If present, engage hoses 4inthere taining
clips on the fuse box and vehicle body. #
If present, inse rtelectrical component 2into
th e holder on the fuse box lid and tighten
scr ews3. #
Insert co ver1 and engage thero tary
catches. Opening and closing t
Opening and closing t
he fuse bo
he fuse box in t
x in the coc
he coc kpit
kpit R
R
eq
eq uir
uir ements:
ements:
R Obser vethe no tes on elect rical fuses
(/ page 457). Breakdown assistance
459
459

R
R
aising t
aising t he v
he vehicle when c
ehicle when c hanging a wheel
hanging a wheel R
R
eq
eq uir
uir ements:
ements:
R There are no persons in theve hicle.
R The vehicle has been prepared for a wheel
ch ange (/ page 470).
R The hub caps ha vebeen remo ved
( / page 470).
Impor tant no tes on using the jack:
R Use only a vehicle-speci/c jack that has been
appr ovedby Mercedes-Benz toraise theve hi-
cle.
R The jack is only designed forra ising and hold-
ing theve hicle for a short time while a wheel
is being changed and not for maintenance
wo rkunder theve hicle.
R The jack must be placed on a /rm, 0at and
non-slip sur face.
R The foot ofthe jack must be positioned verti-
cally under the jack support point. Ru
les of conduct when theve hicle is raised:
R Never place your hands and/or feet under the
ve hicle.
R Never lie under theve hicle. R
Do not start the engine and do not release the
electric parking brake.
R Do not open or close any doors or the boot
lid. #
Using the wheel wrench, loosen the wheel
bolts on the wheel you wish tochange by
about one full turn. Do not unscr ewthe bolts
comple tely. Wheels and tyres
471 471

&
W
WARNI NG
ARNI NGRisk of injury from tightening
wheel bolts and nuts
If yo u tighten the wheel bolts or wheel nuts
when theve hicle is raised, the jack could tip. #
Only tighten wheel bolts or wheel nuts
when theve hicle is on thegr ound. #
Be sure toobser vethe inst ructions and saf ety
no tes on "Changing a wheel" (/ page 465).#
For saf etyre asons, only use wheel bolts which
ha ve been appr oved byMercedes-Benz and
fo rth e wheel in question. #
Tighten the wheel bolts evenly in a diagonal
pattern in the order indicated until they are
/nger-tight. #
Unscr ewand remo vethe centring pin. #
Tighten the last wheel bolt until it is /nge r-
tight. #
Lowe rth eve hicle (/ page 474). Low Low
er
ering t
ing t he v
he vehicle
ehicle aTer
aTera wheel c
a wheel c hange
hange R
R
eq
eq uir
uir ements:
ements:
R The new wheel has been /tted (/ page 473).
* NO
NOTE
TERisk of vehicle jack becoming trap-
ped bythe AIRMATIC system If
th e AIRMATIC system has released air when
ra ising theve hicle, the jack can become trap-
ped when theve hicle is lo wered. #
Start the engine. This adapts theve hicle
le ve l. #
Remo vethe jack from under theve hicle. #
T
To low
o low er t
er the v
he v ehicle:
ehicle: placethera tchet onto
th e he xagon nut of the jack so that the letters
"AB" are visible and turn anti-clockwise. #
Tighten the wheel bolts evenly in a diagonal
pattern in the order indicated 1to5 with
an initial maximum forc e of 80 Nm. #
Tighten the wheel bolts evenly in a diagonal
pattern in the order indicated 1to5 with
th e speci/ed tightening torque of 150 Nm. &
W
WARNING
ARNING Risk of accident due toincor-
re ct tightening torque
The wheels could come loose if the wheel
bolts or wheel nuts are not tightened tothe
prescribed torque. 474
474
Wheels
and tyres

N
N
o
ot
tes on t
es on t ec
echnical data
hnical data
The tech nical data was de term ined in accordance
with EU Directives. The data stated only applies to
ve hicles with standard equipment. You can obtain
fur ther information from a Mercedes-Benz Service
Centre.
Onl Onl y f
y for cert
or cert ain countr
ain countr ies:
ies:you can /n dvehicle-
speci/c vehicle data in theCO C documents (CER-
TIFIC ATE OF CONFORMITY). These documents
are deli vered with your vehicle. On-boar
On-boar
d electr
d electronics
onics N
No
ot
tes on t
es on t am
amper
per ing wit
ing wit h t
h the engine electr
he engine electr onics
onics *
N
NOOTE
TE Prematu rewe arthro ugh improper
maintenance Improper maintenance may cause
vehicle
components towe ar more quickly and the
ve hicle's operating permit may be in validated. #
Always ha veworkon the engine elec-
tronics and related components car ried
out at a quali/ed specialist workshop. *
N
NOOTE
TE Increased wear and tear or damage
caused bymeasures under take nto
increase per form ance Engine management measures under
take nto
increase per form ance can lead toincreased
we ar and tear or damage tothe drive system. #
Do not under take engine management
measures toincrease per form ance. T
T
w
w o-wa
o-wa y r
y radios
adios N
No
ot
tes on
es on /tting
/tting tw
two-wa
o-wa y r
y radios
adios &
W
WARNING
ARNING Risk of accident due to
improper workon two-w ayradios
If two-w ayradios are manipulated or retro/t-
ted incor rectl y,the electromagnetic radiation
from the two-w ayradios can inter fere with the
ve hicle elect ronics and jeopardise the operat-
ing saf ety of theve hicle. #
You should ha veall workon electrical
and electronic components car ried out
at a quali/ed specialist workshop. &
W
WARNING
ARNING Risk of accident from inco rrect
operation of two-w ayradios
If yo u use two-w ayradios in theve hicle
improper ly,th eir electromagnetic radiation
can disrupt theve hicle's elect ronics. This is
true in thefo llowing situations, in particular:
R The two-w ayradio is not connected toan
ex terior aerial.
R The exterior aerial is /tted incor rectly or is
not a lo w-re0ection aerial.
This could jeopardise the operating saf ety of
th eve hicle. #
Have the lo w-re0ection exterior aerial /t-
ted at a quali/ed specialist workshop. #
When operating two-w ayradios in the
ve hicle, alw ays connect them tothe lo w-
re 0ection exterior aerial. Te
ch nical data
477
477