2021 MERCEDES-BENZ S-CLASS SALOON LONG check engine

#
Turn cap 1anti-clockwise and remo veit. #
Top up the engine oil. #
Replace cap 1and turn it clockwise until it
engages. #
Check the oil le vel again (/ page 426). Chec
Chec
king t
king t he coolant lev
he coolant lev el
el &
W
WARNING
ARNING Risk of burns from hot compo-
nent parts in the engine compartment
Cer tain component parts in the engine com-
partment can be very hot, e.g. the engine, the
cooler and parts of theex haust system. #
Allow the engine tocool down and only
to uch component parts described in the
fo llowing. &
W
WARNING
ARNING Risk of scalding from hot cool-
ant
If yo u open the cap, you could be scalded. #
Let the mo tor cool down before opening
th e cap. #
When opening the cap, wear pr otective
glo ves and saf ety glasses. #
Open the cap slo wlytorelease pressure. #
Only ha vethe coolant checked or re/lled at a
qu ali/ed specialist workshop. T
T
opping up t
opping up t he windscr
he windscreen w
een washer syst
asher syst em
em &
W
WARNING
ARNING Risk of injury due tomoving
parts
Components in the engine compartment may
continue torun or start unexpectedly even
when the drive system is switched o..
Obser vethefo llowing if you must open the
bonnet: #
Switch o. theve hicle. #
Neverto uch the danger zones sur round-
ing moving components, e.g. thero tation
area of thefa n. #
Remo vejewe llery and watches. #
Keep items of clo thing and hair away
from moving pa rts. &
W
WARNING
ARNING Risk of burns from hot compo-
nent parts in the engine compartment
Cer tain component parts in the engine com-
partment can be very hot, e.g. the engine, the
cooler and parts of theex haust system. 428
428
Main
tenance and ca re

#
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

V
V
ehicle
ehicle Displa
Displa
y messag
y messag es P
es Possible causes/conseq
ossible causes/conseq uences and
uences andM
MSolutions
Solutions *T
he driver's displ ayis inoperative due toafa iled soTware update.
The display message will be shownevery time the engine is star ted. &
W
WARNING
ARNING Risk of accident if the driver display fails
If th e driver display has failed or is malfunctioning, function restrictions in systems releva nt tosaf ety cann otbe
de tected.
The operating saf ety of your vehicle may be impaired. #
Drive on carefull y. #
Have theve hicle checked immediately at a quali/ed specialist workshop. If
th e operating saf ety of your vehicle is impaired, park theve hicle immediately and safel y.Contact a quali/ed special-
ist workshop. &
W
WARNING
ARNING Risk of accident due tofailure of the driver display
In theeve ntthat the driver display fails or malfunctions, you will not recognise function restrictions a.ec ting sys-
te ms releva nt tosaf ety. This may impair ope rating saf ety. #
Park theve hicle safely as soon as possible and notify a quali/ed specialist workshop. Displ
aymessages and warning/indicator lamps
515
515

Displa
Displa
y messag
y messag es P
es Possible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions
If th e driver's display fails, you may not recognise function restrictions a.ec ting systems releva nt tosaf ety or the
speed displa y,forex ample. The operating saf ety of theve hicle may be impaired (/ page 382). #
Have theve hicle checkedby aqu ali/ed specialist workshop immediatel y.
d
Vehicle is operational
Switch off vehicle before
exiting *Y
ou are leaving theve hicle in a ready-to-drive state. #
Get out of theve hicle, secure it against rolling away and take theke y with you. #
Ifyo u do not lea vetheve hicle, switch o. the electrical consumers, e.g. the seat heating. Otherwise, the 12‑V bat-
te ry may dischar geand starting the engine may be possible only with the help of a second battery (jump start).
ï
Operation only possible in
transmission position P *T
he ball neck will not swivel because transmission position h,kor neutral iis selected. #
Depress the brake pedal. #
Engage park position j.
ï Trailer coupling in motion *T
he ball neck is retracting/extending.
Do not attem pttospeed up, slow down or initiate the swivel mo vement using your hand, foot or other aids. During the
swivel mo vement, do not couple a trailer.
When the ball neck has reached an operational position, the display message will disappear. 516 516
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
Cannot start vehicle See
Owner's Manual *T
hevehicle cann otbe star ted. #
Switch theve hicle o. and switch it back on #
Ifth e display message still appears, consult a quali/ed specialist workshop.
+
Top up coolant See Own-
er’s Manual *T
he coolant le vel is too lo w.
* N NO
OTE
TE Engine damage due toinsu1cient coolant #
Avoid long journe yswith insu1cient coolant. #
Add coolant (/ page 428). #
Have the engine cooling system checked at a quali/ed specialist workshop.
ÿ
Coolant Stop Switch off
the vehicle *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. 526
526
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 #
Connect a suitable charge r appr ovedfo r Mercedes-Benz with su1cient charge output tothe jump-start connection
point of the 12 V battery (/ page 448).
The 48 V battery is charge d via thevo ltage con verter in theve hicle.
Possible to start the engine
again *T
he 48 V battery has been charge d automatically via thevo ltage con verter. #
Start theve hicle and drive for a while tocharge the 12 V battery and the 48 V batter y. T T
yr
yr e pr
e pr essur
essur e monit
e monit or
or Displa
Displa
y messag
y messag es P
es Possible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions
Tyre press. monitor cur-
rently unavailable *T
here is inter fere nce from a po werful radio signal source. As a result, no signals from the tyre pressure sensors are
being received. The tyre pressure monitoring system is temp orarily una vailable.
The tyre pressure monitoring system will restart au tomatically as soon as the cause has been recti/ed. #
Drive on.
Tyre press. monitor inoper-
ative *T
he tyre pressure moni toring system is malfunctioning. &
W WARNI NG
ARNI NGThere is a risk of an accident if the tyre pressure monitoring system is malfunctioning
The tyre pressure monitoring system cannot issue a warning if there is pressure loss in one or more of the tyres.
Ty res with insu1cient tyre pressure may impair the driving characteristics as well as steering and braking. #
Have the tyre pressure monitoring system checked at a quali/ed specialist workshop. 562
562
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 #
Switch o. theve hicle. #
Add 1 l of engine oil (/ page 427). #
Check the engine oil le vel.
No tes on engine oil (/ page 487).
5
Engine oil pressure Stop
Switch off the vehicle *T
he oil pressure is too lo w.
* N NO
OTE
TE Engine damage caused bydriving with insu1cient oil pressure #
Avoid driving with insu1cient oil pressure. #
Stop theve hicle immediately in accordance with the tra1c conditions. Do not continue driving. #
Switch o. theve hicle. #
Consult a quali/ed specialist workshop.
5
Engine oil level cannot be
measured *T
he elect rical connection tothe oil le vel sensor has been inter rupted or the oil le vel sensor is faulty. #
Consult a quali/ed speciali stwo rkshop. 570 570
Displ
aymessages and warning/indicator lamps

W
W
ar
ar ning/indicat
ning/indicat or lampP
or lam pP ossible causes/conseq
ossible causes/consequences and uences andM
MSolutions
Solutions
;
Engine diagnosis warning
lamp *T
he yellow engine diagnostics warning lamp is lit while the engine is running.
A malfunction has occur red in the engine, theex haust system or the fuel system.
The emissions limit value may ha vebeen exceeded and the engine may be running in eme rgency operation mode. #
Have theve hicle checked as soon as possible at a quali/ed specialist workshop.
V
V ehicles wit
ehicles wit h a diesel engine:
h a diesel engine: the fuel tank may ha vebeen run dr y. #
Start the engine thre eto four times aTer refuelling.
If th eye llow engine diagnosis warning lamp goes out, emer gency ope ration mode is cancelled. The vehicle need not
be checked.
p Engine operating temp era-
ture warning lamp *V
Vehicles wit
ehicles wit h a pe
h a petr
trol engine:
ol engine: aTer a cold start, the blue engine operating temp erature warning lamp is on.
Engine output and engine torque arereduced. #
Take this into consideration in your driving style.
#
Electrical fault warning lamp *T
hered electrical fault warning lamp is lit.
There is a fault in the electrics. #
Notethe messages on the driver's displa y.580
580
Display message
s andwarning/indicator lamps