2021 MERCEDES-BENZ C-CLASS CABRIOLET warning light

*
NO
TEDama getothe battery from over‐
vo ltage When
charging using a bat tery charge r with‐
out a restriction of the maximum charging
vo ltage, the battery or the on-board electron‐
ics can be damaged. #
Only use battery charge rs with a maxi‐
mum charging voltage of 14.8 V. All
other vehicles
When charging the battery and during starting
assis tance, al ways use the jump-s tart connec‐
tion point in the engine compartment.
* NO
TEDama getothe battery from over‐
vo ltage When
charging using a bat tery charge r with‐
out a restriction of the maximum charging
vo ltage, the battery or the on-board electron‐
ics can be damaged. #
Only use battery charge rs with a maxi‐
mum charging voltage of 14.8 V. &
WARNING Risk ofexplosion from hydro‐
ge nga s igniting
There is a danger of hydrogen gas igniting
when charging the battery if there is a short
circuit or spar ksstart toform. #
Make sure that the positive term inal of
th e connected battery does not come
into conta ct withvehicle parts. #
Never place me tal objects or tools on a
batter y. #
The described order of the battery
clamps must be obser ved when con‐
necting and disconnecting the batter y. #
When giving starting assis tance, al ways
make sure that you on lyconnect bat‐
te ry term inals with identical polarity. #
During starting assis tance, you must
obse rveth e described order for con‐
necting and disconnecting the jump
lead. #
Do not connect or disconnect the bat‐
te ry cla mp s while the engine is running. &
WARNING Risk ofexplosion during
ch arging process and starting assis tance
During thech arging process and starting
assis tance, the battery may release an explo‐
sive gas mixture. #
Avoid fire , naked flames, creating
spar ksand smoking. #
Make sure there is suf ficient ventila‐
tion. #
Do not lean over a batter y. &
WARNING Risk ofexplosion from a fro‐
zen battery
A dischar ged battery may freeze at temp era‐
tures slightly abo veor below freezing point.
During starting assis tance or battery charg‐
ing, bat tery gas can be released. #
Alw ays allow a battery tothaw before
ch arging it or per form ing starting assis‐
ta nce. Breakdown assi
stance 383

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

#
Adjust the tyre pressure where neces‐
sar y. Ty
re pressure which is too high or too low can:
R Shor tenth e service life of the tyres.
R Cause increased tyre damage.
R Adversely af fect driving characteristics and
th us driving saf ety, e.g. due toaquaplaning. &
WARNING Risk of accident due torepea‐
te d pressure drop in the tyres
The wheels, valves or tyres could be dam‐
aged.
To o low a tyre pressure can lead tothe tyres
bur sting. #
Examine the tyres forfo re ign objects. #
Check whe ther the tyre has a puncture
or theva lve has a leak. #
Ifyo u are unable torectify the damage,
conta ct aqualified specialist workshop. Information on
there commended tyre pressure
fo rth eve hicle's factor y-fitted tyres can be found on
the tyre pressure table on the inside of the
fuel filler flap (/ page 397).
Use a suitable pressure gauge tocheck the tyre
pressure. The outer appearance of a tyre does
not permit any reliable conclusion about the tyre
pressure.
Only cor rect tyre pressures when the tyres are
cold. Conditions for cold tyres:
R The vehicle has been par ked with the tyres
out of direct sunlight for at least thre e hours.
R The vehicle has tr avelled less than 1.6 km.
The vehicle's tyres heat up when driving. As the
te mp erature of the tyres increases, so too does
th e tyre pressure.
Ve hicles with a tyre pressure monitoring sys‐
te m: you can also check the tyre pressure using
th e on-board computer.
Note s on trailer operation
Alw ays inflate there ar axle tyres tothere com‐
mended tyre pressures on the tyre pressure
ta ble for increased load. Ty
re pressure table The tyre pressure
table is on the inside of the
fuel filler flap. If one or more tyre sizes precede a tyre pres‐
sure, thefo llowing tyre pressure information is
only valid forth ose tyre sizes and their respec‐
tive load condition. Wheels and tyres
397

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

*
NO
TEOverheating at high outside tem‐
peratures If an inapp
ropriate coolant is used, the
engine cooling sy stem is not suf ficiently pro‐
te cted against overheating and cor rosion at
high outside temp eratures. #
Alw ays use coolant appr ovedby
Mercedes-Benz. #
Obser vethe instructions in the
Mercedes-Benz Specifications for Oper‐
ating Fluids 310.1. Ha
ve the coolant regularly replaced at a qualified
specialist workshop.
Proportion of antifreeze concentrate in the
engine cooling sy stem:
R a minimum of 50% (antifreeze pr otection
down toappr oximately -37°C)
R a maximum of 55% (antifreeze pr otection
down to-45°C) Note
s on windscreen washer fluid Obser
vethe no tes on operating fluids
(/ page 416). &
WARNING ‑ Risk of fire and injury due to
windscreen washer concentrate
Wi ndsc reen washer concentrate is highly
fl ammable. It could ignite if it comes into
con tact wi thhot engine component parts or
th eex haust sy stem. #
Make sure that no windsc reen washer
concentrate spills out next tothefiller
opening. *
NO
TEDama getotheex terior lighting
due tounsuitable windsc reen washer
fl uid Uns
uitable windsc reen washer fluids may
damage the plastic sur face of theex terior
lighting. #
Only use windscreen washer fluids
which are also suitable for use on plas‐ tic sur
faces, e.g. MB SummerFit or MB
Wi nterFit. *
NO
TEBlocked spr aynozzles caused by
mixing windscreen washer fluids #
Do not mix MB SummerFit and MB Win‐
te rFit with other windscreen washer flu‐
ids. Do not use distilled or de-ionised
water.Other‐
wise, thefill le vel sensor may be triggered er ro‐
neously.
Re commended windscreen washer fluid:
R abo vefreezing point: e.g. MB SummerFit
R below freezing point: e.g. MB WinterFit
Fo rth e cor rect mixing ratio, referto the informa‐
tion on the antif reeze conta iner.
Mix washer fluid with windsc reen washer fluid all
ye ar round. Te
ch nical da ta425

Lights
Display messages
Possible causes/consequences and M
MSolutions
: Left dipped beam (examp le) *T
he cor responding light source is defective. #
Drive on carefully. #
Consult a qualified specialist workshop immediatel y.
% LED light sources: the display message forth e cor responding light appears only when allthe light-emitting
diodes in the light are faulty.
: Malfunction See Owner's
Manual *T
heexterior lighting is malfunctioning. #
Consult a qualified specialist workshop.
* Ve hicles with a trailer hitch: a fuse may haveblown. #
Stop theve hicle in accordance with the tra ffic conditions. #
Check the fuses and replace them if necessary (/ page 391).
:
Automatic driving lights
inoperative *T
he light sensor for auto matic driving lights is malfunctioning. #
Consult a qualified specialist workshop. 438
Display messages and warning/indicator lamps

Display messages
Possible causes/consequences and M
MSolutions
: Active Light System inoper-
ative *T
he active headlamp s are malfunctioning. #
Consult a qualified specialist workshop.
: Switch on headlamps *Y
ou are driving without lo w-beam headlamps. #
Turn the light switch totheL orà position.
:
Switch off lights *Y
ou are leaving theve hicle and the lights are still switched on. #
Turn the light switch totheà position.
: Intelligent Light System
inoperative *T
he Intelligent Light Sy stem is malfunctioning. The lighting sy stem continues tofunction proper lywithout the func‐
tions of the Intelligent Light Sy stem. #
Consult a qualified specialist workshop. Display messages and
warning/indicator lamps 439

Display messages
Possible causes/consequences and M
MSolutions #
Ifth e display message still appears, consult a qualified specialist workshop. Driving saf
ety sy stems Display messages
Possible causes/consequences and M
MSolutions
!
÷ currently unavailable See
Owner's Manual *
ABS and ESP ®
are temp orarily una vailable.
Other driving sy stems and driving saf ety sy stems (e.g. BAS) may also be temp orarily una vailable.
The brake sy stem will continue tooperate normally. Braking dis tance may increase in an emergency braking situa‐
tion. &
WARNING Risk of skidding if ABS and ESP ®
are malfunctioning
The wheels may lock du ring braking and ESP ®
does not pe rform any vehicle stabilisation.
The steerability and braking characteristics are heavily impaired and the braking dis tance may increase. In addi‐
tion, other driving saf ety sy stems are switched off. #
Drive carefully on a suitable stre tch of road, making slight steering mo vements at a speed abo ve30 km/h. #
Ifth e display message does not disappear, consult a qualified specialist workshop immediately. Drive care‐
full y. Displ
aymessa ges and warning/indicator lamps 467