check engine MERCEDES-BENZ C-CLASS CABRIOLET 2021 Owners Manual

Ste
ering wheel Ad
justing the steering wheel manually &
WARNING Risk of inju ryifve hicle set‐
tings are adjus ted while theve hicle is in
motion
Yo u could lose cont rol of theve hicle in par‐
ticular in thefo llowing situations:
R Ifyo u adjust the driver's seat, the head
re stra ints, thesteering wheel or the mir‐
ro r while theve hicle is in motion.
R Ifyo ufast enyour seat belt while theve hi‐
cle is in motion. #
Before starting the engine: adjust the
driver's seat, head restra ints, steering
wheel and mir ror in particular and fas‐
te nyo ur seat belt. &
WARNING Risk of entrapment forch il‐
dren when adjusting thesteering wheel
Children could injure themselves if they
adjust thesteering wheel. #
Never lea vechildren unat tended in the
ve hicle. #
When leaving theve hicle, alw aysta ke
th eke y with you and lock theve hicle. #
Tounlo ck:push release le ver1 down as
fa r as it will go. #
Adjust height 2and di stance 3tothe
st eering wheel. #
Tolock: pushrelease le ver1 up as far as it
will go. #
Check and make sure that thesteering col‐
umn is loc kedby moving thesteering wheel. Ad
justing the steering wheel electrically The
steering wheel can be adjus ted when the
po we r supp lyis disconnected. 106
Seats and stowing

#
Toswitch on the po wer supp ly:press the
1 button once.
Yo u can, forex ample, activate the wind‐
screen wiper.
The po wer supp lyis switched off again if thefo l‐
lowing conditions are me t:
R You open the driver's door.
R You press but ton1 twice more. #
Toswitch on the ignition: pressthe1 but‐
to n twice.
Indicator and warning lamps appear in the
instrument clus ter.
The ignition is switched off again if one of the
fo llowing conditions is me t:
R You do not start theve hicle within
15 minutes and the transmission is in posi‐
tion jorthe electric parking brake is
applied.
R You press but ton1 once. St
arting theve hicle St
arting theve hicle with thest art/s top but‐
ton &
DANG ER Risk of death caused by
ex haust gases
Combustion engines emit poisonous exhaust
ga ses such as carbon monoxide. Inhaling
th ese exhaust gases is hazardous tohealth
and leads topoisoning. #
Never lea vethe engine or, if present,
th e auxiliary heating running in an
enclosed space wi thout suf ficient venti‐
lation. &
WARNING Risk offire due toflammable
material in the engine compartment or
th eex haust sy stem
Flammable materials may ignite. #
Therefore, check regularly that there
are no flammable materials in the
engine compartment or on theex haust
sy stem. Re
quirements:
R theke y is in theve hicle and is recognised. #
Shift the transmission toposition jori. #
Depress the brake pedal and press button
1 once. #
Ifth eve hicle does not star t:switch off non-
essential consumers and press button 1
once. #
Ifth eve hicle still does not start and the dis‐
play message Place the key in the marked
space See Owner's Manual also appears in
th e multifunction display: start theve hicle
with theke y in the mar ked space (emer gency
operation mode) (/ page 139).
% You can swit choff the engine while driving.
By pressing button 1for about thre e sec‐
onds or bypressing button 1thre e times
within thre e seconds. Be sure toobser vethe
saf ety no tes under "Driving tips"
(/ page 142).
Obse rve any information rega rding display mes‐
sages that can be displa yed in the multifunction
displa y. 13 8
Driving and pa rking

St
arting theve hicle with theke y in the
ma rked space (emer gency operation mode)
If th eve hicle does not start and thePlace the
key in the marked space See Owner's Manual
message appears in the multifunction displa y,
yo u can start theve hicle in emer gency operation
mode. #
Makesure that the mar ked space 2is
em pty. #
Remo vetheke y1 from theke yring. #
Place theke y1 inthe mar ked space 2on
th e symbol 3.
The vehicle will start af ter a short time.
If yo ure mo vetheke y1 from the mar ked
space 2,the engine continues running. For
fur ther engine starts ho wever,th eke y1
must be located in the mar ked space 2on
th e symbol 3during the entire journe y. #
Have theke y1 checked at a qualified spe‐
cialist workshop.
If th eve hicle does not star t: #
place theke y1 inthe mar ked space 2
and lea veitth ere. #
Depress the brake pedal and start theve hi‐
cle using thest art/ stop button.
% You can also swit chon the po wer supp lyor
th e ignition with thest art/ stop button.
Obser veany information rega rding display mes‐
sages that can be displa yed on the multifunction
displa y. St
arting theve hicle via Remo teOnline Serv‐
ices Cooling or heating
theve hicle interior before
st arting the jou rney
Ensu rethefo llowing before starting the engine:
R the legal stipulations in the area where your
ve hicle is par ked allow engine starting via
smartphone.
R it is safe tostart and runth e engine where
yo ur vehicle is par ked.
R the fuel tank is su fficiently full.
R thest ar ter battery is suf ficiently charge d.
Charging thest ar ter battery be fore starting
th e jou rney
If th eve hicle battery is dischar ged, you can
re cei vea message on your smartphone. You can
th en start theve hicle with the smartphone to
ch arge the batter y.The vehicle is automatically
switched off af terte n minu tes. Driving and parking
13 9

#
Release the brake pedal. #
Switch the ignition off.
% Ifyo uth en exitth eve hicle leaving theke y in
th eve hicle, the automatic transmission
re mains in neutral i.
Engaging park position P #
Obser vethe no tes on parking theve hicle
(/ page 161). #
Dep ress the brake pedal until theve hicle
comes toast andstill. #
When theve hicle is at a standstill, press but‐
to nj.
When the transmission position display
sho wsj,th e park position is engaged. If no
transmission position display jappears,
secure theve hicle topreve nt it from rolling
aw ay.
% Depending on the situation, it may take a
short time until jis engaged. Therefore,
alw ays pay attention tothe transmission
position displa y. Pa
rk position jis engaged automatically if one
of thefo llowing conditions is me t:
R You swit choff the ignition when theve hicle
is stationary and the transmission position is
h ork.
R You open the driver's door when theve hicle
is at a standstill or when driving at a very low
speed and the transmission position is hor
k.
% Tomanoeuvre with an open driver's door,
open the driver's door while at a standstill
and engage transmission position hork
again.
Engaging drive position D #
Depress the brake pedal and push the
DIRECT SELECT le ver down past thefirst
point of resis tance.
When the automatic transmission is in transmis‐
sion position h, it shiftsthege ars automati‐
call y.This depends, among other things, on the
fo llowing factors:
R The selected drive program
R The position of the accelera tor pedal R
The driving speed Problems with
the transmission The transmission has a
faulty gear shift
Po ssible cause:
R the transmission is losing oil. #
Have the transmission checked at a qualified
specialist workshop immediately.
The acceleration characteristics getwo rse,
and the transmission no longer shifts.
Po ssible cause:
R the transmission is in emer gency operation
mode: it is only possible toshift toone gear
and reve rsege ar. #
Stop theve hicle in accordance with the traf‐
fi c conditions. #
Shift the transmission toposition j. #
Switch off the engine. #
Wait at least ten seconds. #
Tryto start the engine again. 15 2
Driving and pa rking

fi
ed based on the actual operating conditions
and/or loads.
Examples of arduous operating conditions:
R regular city driving with frequent intermedi‐
ate stops
R mainly short-dis tance driving
R frequent operation in mountainous terrain or
on poor road sur faces
R when the engine is of ten le ftidling for long
periods
R operation in particula rly dusty conditions
and/or if air-recirculation mode is frequently
used
In these or similar operating conditions, ha vethe
interior air filter, engine air cleaner, engine oil
and oil filter etc. changed more frequent ly. The
ty re s must be checked more frequently if the
ve hicle is operated under increased loads. Fur‐
th er information can be obtained at a qualified
specialist workshop. Battery disconnection periods
The ASS
YST PLUS service inter val display can
calculate the service due date only when the
battery is connec ted. #
Notedown the service due date displa yed on
th e instrument display before disconnecting
th e battery (/ page 354). Engine compartment
Ac
tive bonn et(pedestrian pr otection) Operation of
the active bonnet (pedestrian
pr otection)
In cer tain accident situations, the actuation of
th e active bonn etreduces therisk of injury to
pedestrians. The rear area of the bonn etis
ra ised byappr oximately 85 mm.
Fo rth e drive tothewo rkshop, reset the actuated
active bonn etyourself (/ page 355).
Af terth e active bonn ethas been actuated,
pedestrian pr otection may be limited.
Ha ve the full functionality of the active bonn et
re stored in a qualified specialist workshop. Re
setting the active bonnet &
WARNING Risk of bu rns from hot com‐
ponent parts in the engine compartment
Cer tain component parts in the engine com‐
partment can be very hot, e.g. the engine,
th e cooler and parts of theex haust sy stem. #
Allow the engine tocool down and only
to uch co mponent parts described in
th efo llowing. Maintenance and care
355

#
Push handle 1ofthe bonn etcatch up wards
and lift the bonn etuntil it opens automati‐
call y.
Closing the bonnet #
Lowe rth e bonn etto a height of around
20 cm and then allow it tofall, applying a lit‐
tle forc e as you let it go. #
Ifth e bonn etcan still be lif ted slightl y,open
th e bonn etagain and close it with a little
more forc e until it engages cor rectly. Engine oil
Che
cking the engine oil le vel using the oil
dip stick &
WARNING Risk of bu rns from hot com‐
ponent parts in the engine compartment
Cer tain component parts in the engine com‐
partment can be very hot, e.g. the engine,
th e cooler and parts of theex haust sy stem. #
Allow the engine tocool down and only
to uch co mponent parts described in
th efo llowing. Re
quirements:
R The engine has an oil dipstic k.If not, the
engine oil le vel can be checked only with the
on-board computer (/ page 359) . Depending on
the engine, the oil dipstick may be
ins talled in the engine compartment in dif fere nt
locations.
The waiting time before checking the oil le vel
when the engine is at normal operating temp era‐
ture is five minutes. #
Park theve hicle on a le vel sur face. #
Pull oil dipstick 1out and wipe off. 358
Maintenance and care

#
Slowly slide oil dipstick 1into the guide
tube tothestop, and pull it out again af ter
about thre e seconds.
R Oil le vel is cor rect: oil le vel is between 2
and 3.
R Oil le velto o low: oil le vel is at 3or
belo w.
R Oil le velto o high: oil le vel is abo ve2 . #
Ifth e oil le vel is too lo w,top up with 1 litre of
engine oil. #
Ifth e oil le vel is too high, drain off excess
engine oil. Consult a qualified specialist
wo rkshop.
Checking the engine oil le vel using the on-
board compu ter
Re quirements:
R The engine has an oil le vel sensor. If not, the
engine oil le vel can be checked only with the
oil dipstick (/ page 358).
R The engine has been warmed up.
R The vehicle is par ked on a le vel sur face.
R The engine is running at idle speed. R
The bonnet is closed.
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.
On-board computer: 4 Service 5
Engine oil level
One of thefo llowing messages will appear 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": #
Add 1 l of 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 any excess engine oil that has been
added. Todo so, consult a qualified specialist
wo rkshop.
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 : The oil
le ve l sensor is defective or not connec ted. #
Consult a qualified specialist workshop.
R Engine oil level System currently unavail. #
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 component parts in the engine com‐
partment can be very hot, e.g. the engine,
th e cooler and parts of theex haust sy stem. Maintenance and care
359

#
Allow the engine tocool down and only
to uch co mponent parts described in
th efo 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. #
Follow the instructions on the service
inter val display forch anging the engine
oil and obser vethe prescribed change
inter vals. #
Do not use additives. *
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. %
Depending on driving style, theve hicle con‐
sumes up to0.8 litr e of oil pe r10 00 km. The
oil consum ption may be higher than this
when theve hicle is new or if you frequently
drive at high engine speeds. #
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 358). 360
Maintenance and care

Checking
the coolant le vel &
WARNING Risk of bu rns from hot com‐
ponent parts in the engine compartment
Cer tain component parts in the engine com‐
partment can be very hot, e.g. the engine,
th e cooler and parts of theex haust sy stem. #
Allow the engine tocool down and only
to uch co mponent parts described in
th efo llowing. &
WARNING Risk of scalding from hot
coolant
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
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.
% Further information on coolant
(/ page 424) 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 component parts in the engine com‐
partment can be very hot, e.g. the engine,
th e cooler and parts of theex haust sy stem. Maintenance and care
361

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.
All vehicles
* 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 only be pr ovided
using vehicles, batteries or other jump start
devices with a nominal voltage of 12V.
R The vehicles must not touch.
R Vehicles with a petrol engine: jump-start
th eve hicle only when the engine and exhaust
sy stem are cold. St
arting assi stance and charging the12 V
battery Preparing
starting assi stance/charging #
Secure theve hicle byapplying the electric
parking brake. #
Automatic transmission: shiftthe trans‐
mission toposition j. #
Manual transmission: shiftthe transmis‐
sion toneutral. #
Switch off the ignition and all electrical con‐
sumers. #
Open the bonn et. 384
Breakdown assis tance