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

#
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

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

Occupant saf
ety Wa
rning/indicator lamp
Possible causes/consequences and M
MSolutions
6 Re stra int sy stem warning
lamp *T
he redre stra int sy stem warning lamp is lit while the engine is running.
The restra int sy stem is malfunctioning (/ page 38). &
WARNING Risk of inju rydue tomalfunctions in there stra int sy stem
Components in there stra int sy stem may be activated unintentionally or not deploy as intended in an accident. #
Have there stra int sy stem checked and repaired immediately at a qualified specialist workshop. #
Drive on carefully. #
Notethe messages on the multifunction displa y. #
Consult a qualified specialist workshop immediatel y.
ü
Seat belt warning lamp *T
he red seat belt warning lamp flashes and an intermit tent wa rning tone sounds.
or
The red seat belt warning lamp lights up once the engine has star ted.
In addition, an intermittent warning tone may sound.
The red seat belt warning lamp flashes and an intermit tent wa rning tone sounds:
The driver or front passenger has not fastened his or her seat belt while theve hicle is in motion. #
Fasten your seat belt (/ page 42).
There are objects on the front passenger seat. Display messages and
warning/indicator lamps 487

City lighting
................................................ 124
Cleaning see Care
Climate control Activating/deactivating the A/C
function (cont rol panel)........................ .134
Ac tivating/deactivating the synchro‐
nisation function (cont rol panel)............ 13 4
Air-reci rculation mode.......................... .134
Au tomatic control.................................. 13 4
Demi sting the windscreen..................... 13 3
Demi sting windo ws............................... 13 4
Fr ont air vents....................................... 13 5
Ionisation............................................... 13 4
No te...................................................... 13 3
Re ar air vents....................................... .135
Setting the air distribution..................... 13 3
Setting the air flow ................................. 13 3
Setting theve hicle interior temp era‐
ture........................................................ 13 3
Switching on/of f................................... 13 3
Switching there ar wind owheater
on/off...................................................1 33
THERMATIC control pane l...................... 13 3
THERMOTRONIC contro l panel..............133 Ve
ntilating theve hicle (con venience
opening).................................................. 90
Co ckpit
Overview................................................... 6
Co ffee cup symbol
see ATTENTION ASSIST
Collision de tection (pa rked vehicle)
Information............................................ 16 6
COMAND Online see Multimedia sy stem
COMAND Touch
Managing devices.................................. 261
Combination switch .................................. 121
Compass................................................... .294
Compu ter
see On-board computer
Connection status
Displ aying.............................................. 325
Overview............................................... 325
Contacts Calling up.............................................. 304
Deleting................................................. 305
Downloading (from mobile phone)........ 303 Importing.............................................. 304
Importing (o
verview)............................. 304
Information........................................... .303
Making a call......................................... 305
Na me form at......................................... 304
Options................................................ .305
St oring..................................................3 05
Controller Operating.............................................. 24 9
Con venience closing ................................... 90
Con venience opening ..................................90
Coolant (engine) Check le vel............................................ 361
No tes..................................................... 424
Cooling see Climate control
Co pyright..................................................... 36
Cornering light ...........................................1 22
Cross Traf fic Alert..................................... .218
Crosswind Assist Function/no tes...................................... 171 Index
507

DIRECT SELECT le
ver
Engaging drive position........................ .152
Engaging neutral................................... .151
Engaging pa rkposition.......................... 15 2
Engaging pa rkposition automatically....1 52
Engaging reve rsege ar........................... .151
Fu nction................................................ 15 0
Display (care) ............................................ .369
Display (multimedia sy stem)
Settings................................................. 256
Display (on-boa rdcompu ter)
Displ ays on the multifunction displa y.... 229
Displ aymessage
Calling up (on-board compu ter)............ .430
No tes....................................................4 30
Display messages ¯ - - - km/h ..................................... 457
ç - - - km/h ..................................... 458
È - - - km/h ..................................... 457
# 12V battery See Owner's Man‐
ual......................................................... 472K
12V battery See Owner's Man‐
ual......................................................... 437
Û 48 V battery See Owner's Man‐
ual..........................................................4 74
: Active Light Sy stem inoperative... 439
¯ AdBlue sy stem fault Emer. op.:
max. XXX mphSt art not poss. in XXX
miles .................................................... .482
¯ AdBlue sy stem fault Emer‐
ge ncy op. in XXX km See Owner's
Manual.................................................. 481
¯ AdBlue sy stem fault Engine
st art not possible................................. .482
¯ AdBlue sy stem fault See Own‐
er's Manual ............................................ 481
5 Add 1 litre engine oil when
next refuelling....................................... 483
é ATTENTION ASSIST inoperative ....456
é ATTENTION ASSIS T:Take a
break!....................................................4 56:
Automatic driving lights inoper‐
ative...................................................... 438
Á Change key bat teries ...................4 34
J Checkbrake fluid le vel................. 455
5 Check engine oil le vel when
next refuelling....................................... 483
ï Checktrailer hitch lo ck................ 441
h Check tyre(s) ................................ 476
! Clean the fuel filter ...................... 448
J Close boot separator .................... 437
K Convertible Top Operation pos‐
sible to60 km/h................................... 436
ÿ Coolant Stop vehicle Switch
engine off..............................................4 46
! currently una vailable See Own‐
er's Manual ............................................ 467
÷ currently una vailable See Own‐
er's Manual .......................................... .468
5 Engine oil le vel cannot be
measured .............................................. 485 Index
509

Emer
gency braking
see BAS (Brake Assi stSystem)
Emer gency engine start ............................ 391
Emer gency key
Inserting/removing.................................74
Locking/unlocking the doors.................. 79
Emer gency operation mode
St arting theve hicle...............................1 39
Emer gency spare wheel
No tes..................................................... 41 0
ENERGIZING COMFORT Overview of programmes...................... 268
St arting the programme........................ 268
Engine ECO start/ stop function........................ 14 5
Engine number....................................... 414
St arting (eme rgency operation mode).. .139
St arting (Remo teOnline).......................1 40
St arting (s tart/s top button).................. 13 8
St arting assis tance................................ 384
Switching off (s tart/s top button)...........1 61
Engine bonnet Function (active bonnet)........................ 355 Opening/closing................................... 356
Engine data Displaying.............................................. 15 0
Engine electronics Notes..................................................... 412
Engine number .......................................... .414
Engine oil Additives...............................................4 22
Capacity................................................ 423
Che cking the oil le vel using the oil
dipstick................................................. 358
Checking the oil le vel using the on-
board computer..................................... 359
MB-Fr eigabe or MB-Appr oval................ .423
Quality................................................... 423
To pping up............................................. 359
Entering characters
Fu nction/no tes..................................... 254
On theto uchpad.................................. .256
Using the controller............................... 255
EQ Boost technology
Operating saf ety...................................... 23 ERA-G
LONA SS test mode
St arting/ending.................................... .321
Er ro r message
see Displ aymessa ge
ESC (Electronic Stability Control)
see ESP ®
(Electronic Stability Prog ram)
ESP ®
Crosswind Assis t.................................. .171
Tr ailer stabilisation................................ 172
ESP ®
(Electronic Stability Prog ram)
Ac tivating/deactivating......................... 172
Fu nction/no tes..................................... 17 0
EU general operating permit number ......414
Exterior lighting Care...................................................... 368
Exterior lighting see Lights F
Fa tigue de tection
see ATTENTION ASSIST
Favo urites
Ad ding................................................... 252 Index
515

Wa
rning triangle
Re moving............................................... 372
Setting up.............................................. 373
Wa rning/indicator lamp
! ABSwarning lamp....................... .495
J Brake sy stem warning lamp
(red)...................................................... 493
J Brake sy stem warning lamp
(yellow).................................................. 493
ÿ Coolant warning lamp................. .489
! Electric parking brake indicator
lamp (red).............................................. 492
# Electrical fault warning lamp....... .491
; Engine diagnosis warning lamp... .491
å ESP®
OFF warning lamp.............. .497
÷ ESP®
wa rning lamp..................... .496
8 Fuelreser ve wa rning lamp
lights up................................................ 492
Ù Powe rst eering warning lamp
(red)...................................................... 488 6
Restra int sy stem warning lamp... .487
ü Seat belt warning lamp................ 487
ä Suspension warning lamp (yel‐
low)....................................................... 495
! The elect ric pa rking brake (yel‐
low) indicator lamp............................... .492
ï Trailer tow hit chwarning lam p..... 489
h Tyre pressure monitoring sys‐
te m wa rning lamp................................. .498
L Warning lamp for dis tance
wa rning function................................... .494
Overview............................................... 485
Wa rning/indicator lamps
PA SSENGER AIR BAG.............................. 49
Wa rranty ...................................................... 32
Wa sher fluid
see Windsc reen washer fluid
Wa shing byhand (care)............................ 364
Wa ter tank
see Air-water duct We
ather information ................................. 295
What3words Destination entry with a 3 word
address................................................. 275
Wheel change
Fitting a new wheel............................... 408
Lo we ring theve hicle.............................4 09
Prepa ration.......................................... .405
Ra ising theve hicle................................4 06
Re moving a wheel................................. 408
Re moving/fitting hub caps................... .405
Wheel change
see Emergency spa rewheel
Wheel rotation .......................................... .403
Wheels Care ...................................................... 368
Checking............................................... 395
Checking the tyre pressure (tyre
pressure monitoring sy stem)................. 398
Fitting.................................................... 408
Flat tyre.................................................3 74
Inter changing....................................... .403
MOExtended tyres................................. 375
Noise.....................................................3 95 Index
537