ignition MERCEDES-BENZ C-CLASS CABRIOLET 2021 Repair Manual

If
th e preceding tyre sizes are complemented by
th e+ symbol, the tyre pressure information
fo llowing sho wsalternative tyre pressures. Fuel
consum ption may then increase slightl y.
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 on-board computer (/ page 398).
If th ere is a subs tantial pressure loss or if the
tyre temp erature is excessive, you will be
wa rned with display messages (/ page475) or
th eh warning lamp in the instrument clus ter
( / page 498). 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 matically update 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 399).
Sy stem limits
The sy stem may be impaired or may not function
particularly in thefo llowing situations:
R the tyre pressure has been set incor rectly
R sudden pressure loss caused byafo re ign
object penetrating the tyre, forex ample
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. On-board computer:
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‐ 398
Wheels and tyres

+
ENVIRONMENTAL
NOTEEnvironmental
pollution due todisposing of operating
fl uids in a non-environmen tally responsi‐
ble manner Operating
fluids include thefo llowing:
R fuels
R exhaust gas af tertre atment additives, e.g.
Ad Blue ®
R lubricants
Incor rect disposal of ope rating fluids can
cause considerable damage tothe environ‐
ment. #
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: Te
ch nical da ta417

#
Immedia tely 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. #
Change immediately out of clo thing that
has come into con tact wi thfuel. Flexible-fuel
vehicles can be refuelled with the
fo llowing fuel types:
R unleaded petrol
R E85 fuel
R a mixture of E85 fuel and unleaded petrol
Flexible-fuel vehicles can be identified bythe
Ethanol up toE85 sticke r on the inside of the
fuel filler flap.
Depending on the count ry,th e fuels you can use
in your vehicle may dif fer from the information in
th e Owner's Manual. The fuels that ha vebeen appr
oved foryo ur vehicle can be found on the
instruction label on the inside of the fuel filler
fl ap. Fu
el Information on fuel
grades forve hicles with
petrol engines
Obser vethe no tes on operating fluids
(/ page 416).
* 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: 41 8
Tech nical da ta

#
Neverre fuel using petrol in diesel
engines. #
Never mix petrol with diesel fuel. *
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 sulphu r-free diesel
fuel that con form sto European stand‐
ard EN 590, or an equivalent specifica‐
tion.
In countries without sulphur-f ree diesel
fuel, refuel using only lo w-sulphur diesel
fuel with a sulphur content less than
50 ppm. #
Vehicles without diesel particulate
fi lter: refuel using only diesel fuel with
a sulphur content less than 500 ppm.
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 (/ page155)
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. 420
Tech nical da ta

Display messages
Possible causes/consequences and M
MSolutions
Hazard warning lamps mal-
functioning *T
he hazard warning lamp switch is malfunctioning. #
Consult a qualified specialist workshop. 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 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 discharge and starting the engine may be possible only with the help of a second battery (jump
st art).
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. Display messages and
warning/indicator lamps 441

Display messages
Possible causes/consequences and M
MSolutions
Auxiliary battery malfunc-
tion (white display mes‐
sage) *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.
Auxiliary battery malfunc-
tion (red display message) *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 (/ page166).
If it is not possible toapply the electric parking brake: #
Consult a qualified specialist workshop. Display messages and
warning/indicator lamps 451

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 (/ page166).
or #
Release the electric parking brake automatically (/ page165).
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 (/ page166).
To release: #
Apply and then release the electric parking brake manuall y.452
Display messages and warning/indicator lamps

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 est ate of charge istoo 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 (/ page166).
If it is still not possible toapply the electric parking brake: Display messages and
warning/indicator lamps 453

Display messages
Possible causes/consequences and M
MSolutions
! Turn on the ignition to
release the parking brake *
The red! indicator lamp is lit.
Yo u ha veattem ptedto release the electric parking brake with the ignition switched off. #
Switch on the ignition.
J Check brake fluid level *T
here is insuf ficient brake fluid in the brake fluid reser voir. &
WARNING Risk of an accident due tolow brake fluid le vel
If th e brake fluid le vel is too lo w,the braking ef fect and the braking characteristics may be impaired. #
Stop theve hicle as soon as possible, paying attention toroad and traf fic conditions. Do not continue driv‐
ing. #
Consult a qualified specialist workshop. #
Do not top up the brake fluid. Check brake pads See
Owner's Manual
*T
he brakepads ha vereached thewe ar limit. #
Consult a qualified specialist workshop. Display messages and
warning/indicator lamps 455

Display messages
Possible causes/consequences and M
MSolutions
Active Steering Assist cur-
rently unavailable due to
multiple emergency stops *A
ctive Steering Assist is temp orarily una vailable due tomultiple emergency stops. #
Take ove rth esteering and stop in accordance with the tra ffic conditions. #
Swit chthe ignition off and switch it back on.
Ac tive Steering Assist is available once more.
Beginning emergency stop *Y
our hands are not on thesteering wheel. An emer gency stop is being initiated (/ page188). #
Put your hands back on thesteering wheel.
Yo u can cancel the deceleration at any time byper form ing one of thefo llowing actions:
R Steering
R Braking or accelerating
R Deactivating Active Dis tance Assi stDISTRONIC
Ø *A
ctive Steering Assist has reached the sy stem limits (/ page186).
Yo u ha venot steered independently for a considerable period of time. #
Take ove rth esteering and drive on in accordance with the traf fic conditions.
Traffic Sign Assist currently
unavailable See Owner's
Manual *T
raffic Sign Assist is temp orarily una vailable.
Once the cause of the problem is no longer present, the sy stem will be available again. #
Drive on. #
Ifth e display message does not disappear, stop theve hicle safely and clean the windscreen. 460
Display messages and warning/indicator lamps