ignition MERCEDES-BENZ E-CLASS CABRIOLET 2020 Repair Manual

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. #
Vehicles with automatic transmission
must not be tow- star ted. #
Vehicles with automatic transmission must
not be tow- star ted. 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 can be found in the
fuse assignment diagram.
Fu se assignment diag ram: onthe fuse box in
th e boot (/ page 324). *
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. If
th e newly inser ted fuse also blo ws, ha vethe
cause traced and rectified at a qualified special‐
ist workshop.
Ensure thefo llowing before replacing a fuse:
R The vehicle is secured against rolling away.
R All electrical consumers are switched off.
R The ignition is switched off.
The electrical fuses are located in various fuse
bo xes:
R Fuse box in the engine compartment on the
driver's side (/ page 323)322
Breakdown assis tance

R
Fuse box on the driver's side of the cockpit
(/ page 324)
R Fuse box in the front passenger foot we ll
(/ page 324)
R Fuse box in the boot on theright-hand side
of theve hicle, when vie wed in the direction
of tr avel (/ page 324) Opening and closing
the fuse box in the
engine compa rtment Requ
irements:
R A dry clo thand a sc rewdriver are available.
Obse rveth e no tes on electrical fuses
(/ page 322).
Opening &
WARNING Risk of inju ryfrom using the
windscreen wipers while the engine bon‐
net is open
When the engine bonn etis open, and the
windscreen wipers are set in motion, you can
be trapped bythe wiper linkage. #
Alw ays switch off the windscreen wip‐
ers and ignition before opening the
engine bonn et. #
Turn clips 2on co ver1 anti-clockwise a
qu arter-turn. #
Pull co ver1 upwards in the direction of the
ar row. #
Remo veany existing moisture from the fuse
box using a dry clo th. #
Loosen scr ews4, remo vefuse box lid 3
from theto p.
Closing #
Check whe ther the seal is positioned cor‐
re ctly in lid 3. Breakdown assis
tance 323

The load conditions "partially laden" and "fully
laden" are defined in
theta ble for dif fere nt num‐
be rs of passengers and amounts of luggage. The
actual number of seats may dif fer from this. Ty
re pressure moni toring sy stem Fu
nction of the ty repressure moni toring sys‐
tem
The sy stem checks the tyre pressure and the
tyre temp erature of the tyres fitted totheve hicle
by means of a tyre pressu resensor.
The tyre pressure and the tyre temp erature
appear in the multifunction display
(/ page 328).
If th ere is a subs tantial pressure loss or if the
tyre temp erature is excessive, you will be
wa rned in thefo llowing ways:
R via display messa ges (/ page 405)
R viatheh warning lamp in the instrument
clus ter
The tyre pressure monitoring sy stem is only an
aid. It is the driver's responsibility toset the tyre pressure
tothere commended cold tyre pressure
suitable forth e operating situation.
In most cases, the tyre pressure monitoring sys‐
te m will auto maticallyupdate the new refere nce
va lues af teryo u ha vechanged the tyre pressure.
Yo u can, ho wever,also update there fere nce val‐
ues byrestarting the tyre pressure monitoring
sy stem manually (/ page 427).
Sy stem limits
The sy stem may be impaired or may not function
particular lyin thefo llowing situations:
R the tyre pressure has been set incor rectly
R there is a sudden pressure loss caused, for
ex ample, byafo re ign object penetrating the
tyre
R there is a malfunction caused byano ther
ra dio signal source
Checking the ty repressure with the tyre
pressure moni toring sy stem
Requ irements:
R The ignition is switched on. Driver display:
4 Service 5
Tyres
One of thefo llowing displa ysappears:
R Cur rent tyre pressure and tyre temp erature
of the individual wheels: R
Tyre pressures will be displayed after a few
minutes of driving
R Tyre pressure monitor active: thete ach-in
process of the sy stem is not yet compl ete.
The tyre pressures are already being moni‐
to re d. #
Compare the tyre pressure with there com‐
mended tyre pressure forth e cur rent operat‐ 328
Wheels and tyres

+
ENVIRONMENTAL
NOTEEnvironmental
pollution caused byenvironmen tally ir re‐
sponsible disposal #
Dispose of operating fluids in an envi‐
ro nmentally responsible manner. Operating
fluids include thefo llowing:
R fuels
R DeNOx agent AdBlue ®
forex haust gas af ter‐
treatment
R lubri cants
R coolant
R brake fluid
R windsc reen washer fluid
R climate cont rol sy stem refrigerant
Only use products app rove dby Mercedes-Benz.
Damage caused bythe use of products that ha ve
not been appr oved is not co veredby the
Mercedes-Benz warranty or goodwill gestures.
The operating fluids appr ovedby Mercedes-Benz
can be identified bythefo llowing insc ript ions on
th e conta iner: R
MB- Freigabe (e.g. MB-Fr eigabe 229.51 )
R MB-Appr oval (e.g. MB-App rova l 229.51)
Fu rther information on appr oved operating flu‐
ids:
R inthe Mercedes-Benz Specifications for
Operating Fluids byentering the designation
- at https://be vo.mercedes-benz.com
- inthe Mercedes-Benz BeVo App
R at a qualified specialist workshop &
WARNING Risk offire or explosion from
fuel
Fu els are highly flammable. #
Fire, naked flames, smoking and crea‐
tion of spar ksmust be avoided. #
Swit choff the ignition and, if available,
th est ationary heater, before and while
re fuelling theve hicle. &
WARNING Risk of inju ryfrom fuels
Fu els are poisonous and hazardous to your
health. #
Do not swallow fuel or let it come into
contact with skin, eyes or clo thing. #
Do not inhale fuel vapour. #
Keep children away from fuel. #
Keep doors and windo wsclosed du ring
th ere fuelling process.
If yo u or other people come into contact with
fuel, obser vethefo llowing: #
Immediately rinse fuel off your skin with
soap and water. #
If fuel comes into contact with your
ey es, immediately rinse them thor‐
oughly with clean water.Seek medical
attention immediately. #
Ifyo u swallow fuel, seek medical atten‐
tion immediatel y.Do not induce vomit‐
ing. 346
Tech nical da ta

#
Chan geimmediately out of clo thing that
has come into con tact wi thfuel. Fu
el Information on fuel
grades forve hicles with
petrol engines
Obser vethe no tes on operating fluids
(/ page 345).
* NO
TEDama gecaused bythe wrong fuel Even small amounts of
the wrong fuel could
re sult in damage tothe fuel sy stem, the
engine and the emission control sy stem. #
Only refuel using unleaded, sulphu r-free
petrol that con form sto European
EN 228, or an equi valent specification.
Fu el of this specification may con tain up to
10 %ethanol by volume. Your vehicle is suita‐
ble for use with E10 fuel. Ne
verre fuel with one of thefo llowing fuels:
R diesel
R regular petrol with an octane number
lo we rth an 91 RON
R petrol with more than 10%ethanol byvol‐
ume, e.g. E15, E20, E85, E100
R petrol with more than 3% me thanol by
vo lume, e.g. M15, M30
R petrol with additives con taining me tal
If yo u ha veacciden tally refuelled with the
wrong fuel: #
do not swit ch the ignition on. #
consult a qualified specialist workshop. The
following compatibility indications for fuel
apply to yourvehicle: 1
for petrol with maximum 5% ethanol byvol‐
ume
2 for petrol with maximum 10%ethanol byvol‐
ume
Ac cording toEuropean standard EN 1694 2you
can find the compatibility indications at thefo l‐
lowing locations:
R ontheve hicle on the information label on the
fuel filler flap (/ page169)
R onthe fuel pump or pump nozzle suitable for
yo ur vehicle thro ughout Europe
If th eav ailable fuel is not suf ficiently low in sul‐
phu r,th is can produce unpleasant odours. Te
ch nical da ta347

Ne
verre fuel with one of thefo llowing fuels:
R petrol
R marine diesel
R heating oil
R pure bio-diesel fuel or vege table oil
R paraf fin or kerosene
If yo u ha veacciden tally refuelled with the
wrong fuel: #
Do not swit ch the ignition on. #
Consult a qualified specialist workshop. The
following compatibility indication for fuel
applies to yourvehicle: 1
For diesel fuel with a maximum of 7% byvol‐
ume bio-diesel (fatty acid me thyl es ter)
Ac cording toEuropean standard EN 1694 2you
can find the compatibility indications at thefo l‐
lowing locations:
R ontheve hicle on the information label in the
fuel filler flap (/ page169)
R onthe fuel pump or pump nozzle suitable for
yo ur vehicle thro ughout Europe
Information on low outside temperatures
Re fuel your vehicle with as much winter diesel
fuel as possible at the beginning of winter. Before
changing overto winter diesel fuel, the
fuel tank should be em pty, if possible. When first
re fuelling with winter diesel fuel, only refuel
using a small amount, e.g. toreser veleve l. The
fuel tank can be filled as usual when next refuel‐
ling.
Fu rther information on fuel can be obtained at a
fi lling station or a qualified specialist workshop.
Ta nk content and reser vefuel
The total capacity of the fuel tank may vary,
depending on theve hicle equipment.
Missing values werenot available at the time of
going topress. Te
ch nical da ta349

Ve
hicle Display messages
Possible causes/consequences and M
MSolutions
d Vehicle is operational
Switch off ignition before
exiting *Y
ou are leaving theve hicle when it is in a ready-to-drive state. #
When you lea vetheve hicle, switch off the ignition, secure theve hicle against rolling away and take theke y with
yo u. #
Ifyo u do not lea vetheve hicle, switch off the electrical consumers, e.g. the seat heating. Otherwise, the12 V
battery may dischar geand it will then be possible tostart theve hicle only with the aid of a second battery
(s ta rting assis tance).
ï Check trailer hitch lock *T
he trailer hitch is not operational during a journey with a trailer. &
WARNING Risk of an accident if the ball neck is not loc ked
The trailer may become de tach ed. #
Stop theve hicle immediately in accordance with the traf fic conditions. Do not continue driving. #
Uncouple the trailer and secure it against rolling away. #
Initiate a new swivel mo vement and do not re-couple the trailer until thewa rning/indicator lamp goes out. #
When the display message disappears, couple up the trailer and drive on.
If th e display message does not disappear, the trailer hitch is malfunctioning and the ball neck is not loc ked. #
Do not couple up the trailer. Drive on without the trailer. No tethere duced ground clearance due tothe
unlo cked ball nec k. Displ
aymessa ges and warning/indicator lamps 371

Display messages
Possible causes/consequences and M
MSolutions
Stop vehicle Leave engine
running Wait Transmission
cooling *T
he transmission is overheating. Pulling away may be temp orarily impaired or not possible. #
Stop theve hicle immediately in accordance with the traf fic conditions. Do not continue driving. #
Lea vethe engine running. #
Wait until the display message disappears before pulling away.
Auxiliary battery malfunc-
tion *T
he auxiliary batteryforth e transmission is no longer being charge d. #
Consult a qualified specialist workshop. #
Untilthen, alw ays select park position jmanually before you swit choff the engine. #
Before leaving theve hicle, apply the electric parking brake. Brakes
Display messages
Possible causes/consequences and M MSolutions
! Parking brake See Owner's
Manual *
The yellow ! indicator lamp is lit. The elect ric pa rking brake is malfunctioning.
To appl y: #
Switch the ignition off and switch it back on. #
Apply the electric parking brake manually (/ page179).
If it is not possible toapply the electric parking brake: #
Consult a qualified specialist workshop. 380
Display messages and warning/indicator lamps

Display messages
Possible causes/consequences and M
MSolutions #
Where necessar y,also secure the par kedve hicle against rolling away.
* The yellow ! indicator lamp and there d! indicator lamp are lit. The elect ric pa rking brake is malfunction‐
ing.
To release: #
Swit chthe ignition off and switch it back on. #
Release the electric parking brake manually (/ page179).
or #
Release the electric parking brake automatically (/ page178).
If it is still not possible torelease the electric parking brake: #
Do not continue driving. Consult a qualified specialist workshop.
* The yellow ! indicator lamp is lit and there d! indicator lamp is flashing. The electric parking brake is mal‐
functioning.
The electric parking brake could not be applied or released. #
Swit chthe ignition off and switch it back on.
To appl y: #
Release and then apply the electric parking brake manually (/ page179).
To release: #
Apply and then release the electric parking brake manuall y. Displ
aymessa ges and warning/indicator lamps 381

Display messages
Possible causes/consequences and M
MSolutions
If it is not possible toapply the electric parking brake or there d! indicator lamp continues toflash: #
Do not continue driving. Consult a qualified specialist workshop. #
Where necessar y,also secure the par kedve hicle against rolling away.
* The yellow ! indicator lamp is lit and there d! indicator lamp flashes for appro ximately ten seconds af ter
th e electric parking brake has been applied or released. It then remains lit or goes out. The electric parking brake is
malfunctioning.
If th ech arge leve l is too lo w: #
Char gethe12 V batter y.
To appl y: #
Switch the ignition off.
The electric parking brake will be applied automaticall y.
If yo u do not wantthe electric parking brake tobe applied, e.g. at an automatic car wash or when theve hicle is
being towe d, lea vethe ignition switched on. This does not include having theve hicle towe d with there ar axle
ra ised.
If th e electric parking brake is not applied automatically: #
Switch the ignition off and switch it back on. #
Release and then apply the electric parking brake manually (/ page179).
If it is still not possible toapply the electric parking brake: 382
Display messages and warning/indicator lamps