2018 MERCEDES-BENZ C-CLASS CABRIOLET engine coolant

Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
?NThe red coolant warning lamp comes on while the engine is running.
The coolant level is too low.
If the coolant level is correct, the airflow to the engine radiator may be blocked or
the electric engine radiator fan may be defective.
The coolant is too hot and the engine is no longer being cooled sufficiently.
XObserve the additional display messages in the multifunction display.
XPull over and stop the vehicle safely and switch off the engine, paying attention
to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 143).
XLeave the vehicle and keep a safe distance from the vehicle until the engine has cooled down.
XCheck the coolant level and add coolant, observing the warning notes
(Ypage 284).
XIf you have to add coolant frequently, have the engine cooling system checked.
XMake sure that the air supply to the engine radiator is not blocked, e.g. by snow,
slush or ice.
XDo not start the engine again until the coolant temperature gauge is below the
red marking. Otherwise, the engine could be damaged.
XDrive to the nearest qualified specialist workshop.
XAvoid heavy loads on the engine as you do so, e.g. driving in mountainous terrain
and stop-and-go traffic.
?N The red coolant warning lamp comes on while the engine is running. A warning
tone also sounds.
The coolant temperature gauge has reached the red marking. The airflow to the
engine radiator may be blocked or the coolant level may be too low.
GWARNING
The engine is not being cooled sufficiently and may be damaged.
Do not drive when your engine is overheated. This can cause some fluids which
may have leaked into the engine compartment to catch fire.
Steam from the overheated engine can also cause serious burns which can occur
just by opening the hood.
There is a risk of injury.
XObserve the additional display messages in the multifunction display.
XPull over and stop the vehicle safely and switch off the engine, paying attention
to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 143).
XLeave the vehicle and keep a safe distance from the vehicle until the engine has
cooled down.
XCheck the coolant level and add coolant, observing the warning notes
(Ypage 284).
XIf you have to add coolant frequently, have the engine cooling system checked.
XMake sure that the air supply to the engine radiator is not blocked, e.g. by snow,
slush or ice.
Warning and indicator lamps in the instrument cluster249
On-board computer and displays
Z

Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
XIf the coolant temperature is below the red marking, drive to the nearest quali-
fied specialist workshop.
XAvoid heavy loads on the engine as you do so, e.g. driving in mountainous terrain
and stop-and-go traffic.
Driving systems
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
·NThe red distance warning lamp lights up while the vehicle is in motion. A warning
tone also sounds.
You are approaching a vehicle, a pedestrian or a stationary obstacle in your line of travel at too high a speed.
XBe prepared to brake immediately.
XPay careful attention to the traffic situation. You may have to brake or take
evasive action.
Further information about Active Brake Assist with cross-traffic function
(
Ypage 71).
Further information on the distance warning function of Active Brake Assist
(
Ypage 65).
250Warning and indicator lamps in the instrument cluster
On-board computer and displays

Additional service products
Import ant safety notes
GWARNIN G
Certain component sin th eengin ecompart-
ment, suc has th eengine, radiato rand part s
of th eexhaust system, can become ver yhot .
Working in th eengin ecompartmen tposes a
ris kof injury.
Wher epossible, let th eengin ecool down and
touch only th ecomponent sdescribed in th e
following.
GWARNIN G
The engin ecompartmen tcontain smoving
components. Certain components, suc has
th eradiato rfan ,may continu eto run or start
again suddenly when th eignition is off .There
is aris kof injury.
If you need to do any wor kinside th eengin e
compartment:
Rswitch off th eignition
Rnever reac hint oth earea wher ethere is a
ris kof danger from moving components,
suc has th efan rotation area
Rremove jewelr yand watches
Rkeep items of clothing and hair ,for exam-
ple, away from moving part s
GWARNING
The coolin gsystem is pressurized, particularly
when th emotor is warm .If you open th ecap ,
you could be scalded if hot coolan tsprays out .
There is aris kof injury.
Let th eengin ecool down before you open th e
cap .Wear gloves and eye protection .Slowly
open th ecap to reliev epressure.
GWARNIN G
Opening th ehoo dwhen th eengin eis over-
heated or when there is afir ein th eengin e
compartmen tcould expos eyou to hot gase s
or other servic eproducts .There is aris kof
injury.
Let an overheate dengin ecool down before
opening th ehood. If there is afir ein th e
engin ecompartment, keep th ehoo dclosed
and contact th efir edepartment.
Checking coolant level
Checking th ecoolan tlevel (example)
XPark th evehicl eon alevel surface.
Only chec kth ecoolan tlevel when th evehicl e
is on alevel surfac eand th eengin ehas cooled
down .
XTurn th eSmartKey to position 2in th eigni-
tion loc k (Ypage 123).
or
XPress th eStart/Sto pbutto ntwice on vehicles
wit hKEYLESS-GO or th eKEYLESS-GO start
function (
Ypage 124).
XCheckth ecoolan ttemperature display in th e
instrumen tcluste r (Ypage 36).
The coolan ttemperature mus tbe belo w
15 8 ‡ (70 †).
XTurn th eSmartKey to position gin th eigni-
tion loc k (Ypage 123).
or
XPress th eStart/Sto pbutto nonce on vehicles
wit hKEYLESS-GO or th eKEYLESS-GO start
function (
Ypage 124).
XSlowly tur ncap :half atur ncounter-clock -
wise and allow excess pressur eto escape.
XTurn cap :further counter-clockwise and
remove it .
If th ecoolan tis at th elevel of marke rbar =
in th efiller neck when cold, there is enough
coolan tin coolan texpansion tan k;.
If th ecoolan tlevel is approximately 0. 6in
(1. 5cm) abov emarke rbar =in th efiller neck
when warm ,there is enough coolan tin expan -
sion tan k;.
284Engine compartment
Maintenance and care

XIf necessary, add coolant that has been tested
and approved by Mercedes-Benz.
XReplace cap:and turn it clockwise as far as
it will go.
For further information on coolant, see
(
Ypage 343).
Adding washer fluid to the windshield
washer system
GWARNING
Windshield washer concentrate could ignite if it comes into contact with hot engine compo-
nents or the exhaust system. There is a risk of
fire and injury.
Make sure that no windshield washer con-
centrate is spilled next to the filler neck.
Example: adding liquid to the windshield
washer system
XTo open: pull cap:upwards by the tab and
open.
XAdd the premixed washer fluid.
XTo close: press cap :onto the filler neck
until it engages.
If the washer fluid level drops below the recom-
mended minimum fluid level of 1.1 US qt (1.0 l),
a message appears in the multifunction display
prompting you to add washer fluid (
Ypage 239).
Further information on washer fluid
(
Ypage 344).
ASSYST PLUS
Service message
The ASSYST PLUS service interval display
informs you of the next service due date. Information on the type of service and service
intervals (see the separate Maintenance Book-
let).
Further information can be obtained at a quali-
fied specialist workshop, e.g. an authorized
Mercedes-Benz Center, or at
http://www.mbusa.com (USA only).
iThe ASSYST PLUS service interval display
does not show any information on the engine
oil level. Observe the notes on the engine oil
level (
Ypage 282).
The multifunction display shows a service mes-
sage for several seconds, e.g.:
RService A in XX Days
RService A Due
RService A Overdue by XX Days
Depending on the operating conditions of the
vehicle, the remaining time or distance until the
next service due date is displayed.
The letter A
orB, possibly in connection with a
number or another letter, indicates the type of
service. A
stands for a minor service and Bfor a
major service.
You can obtain further information from an
authorized Mercedes-Benz Center.
The ASSYST PLUS service interval display does
not take into account any periods of time during
which the battery is disconnected.
Maintaining the time-dependent service sched-
ule:
XNote down the service due date displayed in
the multifunction display before disconnect-
ing the battery.
or
XAfter reconnecting the battery, subtract the
battery disconnection periods from the ser-
vice date shown on the display.
Hiding a service message
XPress the aor% button on the steering
wheel.
Displaying service messages
XSwitch on the ignition.
XUse ò on the steering wheel to call up the
list of menus.
ASSYST PLUS285
Maintenance and care
Z

iThe data shown on the vehicle identification
plate is used only as an example. This data is
different for every vehicle and can deviate
from the data shown here. You can find the
data applicable to your vehicle on the vehicle
identification plate.
Vehicle identification number (VIN)
XSlide the right-hand front seat to its rearmost
position.
XFold floor covering ;upwards.
The VIN is visible :.
The VIN can also be found on the vehicle iden-
tification plate (
Ypage 339).
The VIN can also be found at the lower edge of
the windshield (
Ypage 340).
Engine number
:Engine number (stamped into the crank-
case)
;VIN (on the lower edge of the windshield)
=Emission control information plate, includ-
ing the certification of both federal and Cali-
fornian emissions standards
Service products and filling capaci-
ties
Important safety notes
GWARNING
Service products may be poisonous and haz-
ardous to health. There is a risk of injury.
Comply with instructions on the use, storage
and disposal of service products on the labels
of the respective original containers. Always
store service products sealed in their original
containers. Always keep service products out
of the reach of children.
HEnvironmental note
Dispose of service products in an environ-
mentally responsible manner.
Service products include the following:
RFuels
RLubricants (e.g. engine oil, transmission oil)
RCoolant
RBrake fluid
RWindshield washer fluid
RClimate control system refrigerant
Components and service products must match.
Only use products recommended by Mercedes-
Benz. Damage which is caused by the use of
products which have not been recommended is
not covered by the Mercedes-Benz warranty or
goodwill gestures. Products approved by
Mercedes-Benz are listed in this Operator's
Manual in the appropriate section.
Information on tested and approved products
can be obtained at a Mercedes-Benz Service
Center or on the Internet at
http://bevo.mercedes-benz.com.
You can recognize service products approved by
Mercedes-Benz by the following inscription on
the containers:
RMB-Freigabe (e.g. MB-Freigabe 229.51)
RMB-Approval (e.g. MB-Approval 229.51)
Other designations or recommendations indi-
cate a level of quality or a specification in
accordance with an MB Sheet Number (e.g. MB 229.5). They have not necessarily been
approved by Mercedes-Benz.
340Service products and filling capacities
Technical data

Filling capacities
The followingvalue srefer to an oil chang e
includin gth eoil filter.
ModelCapacit y
C3007.4US qt (7.0l)
C 300 4MATIC
Mercedes-AMG
C 43 4MATIC6.9 US qt (6.5 l)
Mercedes-AMG
C 63
Mercedes-AMG
C 63 S9.5 US qt (9.0l)
Additives
!Do not use any additives in the engine oil.
This could damage the engine.
Brake fluid
GWARNING
The brake fluid constantly absorbs moisture
from the air. This lowers the boiling point of
the brake fluid. If the boiling point of the brake
fluid is too low, vapor pockets may form in the
brake system when the brakes are applied
hard. This would impair braking efficiency.
There is a risk of an accident.
You should have the brake fluid renewed at
the specified intervals.
When handling brake fluid, observe the impor-
tant safety notes on service products
(
Ypage 340).
The brake fluid change intervals can be found in
the Maintenance Booklet.
Only use brake fluid approved by Mercedes-
Benz in accordance with MB-Freigabe or MB-
Approval 331.0.
Information about approved brake fluid can be
obtained at any qualified specialist workshop or
on the Internet at
http://bevo.mercedes-benz.co m.
iHave the brake fluid regularly replaced at a
qualified specialist workshop in accordance
with the replacement intervals and the replacement confirmed in the Maintenance
Booklet.
Coolant
Important safety notes
GWARNING
If antifreeze comes into contact with hot com- ponents in the engine compartment, it may
ignite. There is a risk of fire and injury.
Let the engine cool down before you add anti-
freeze. Make sure that antifreeze is not spilled
next to the filler neck. Thoroughly clean the
antifreeze from components before starting
the engine.
!Only add coolant that has been premixed
with the desired antifreeze protection. You
could otherwise damage the engine.
Further information on coolants can be found
in the Mercedes-Benz Specifications for Ser-
vice Products, MB BeVo 310.1, e.g. on the
Internet at http://bevo.mercedes-benz.com.
Or contact a qualified specialist workshop.
!Always use a suitable coolant mixture, even
in countries where high temperatures prevail.
Otherwise, the engine cooling system is not
sufficiently protected from corrosion and
overheating.
iHave the coolant regularly replaced at a
qualified specialist workshop and the replace-
ment confirmed in the Maintenance Booklet.
Comply with the important safety notes for ser-
vice products when handling coolant
(
Ypage 340).
The coolant is a mixture of water and anti-
freeze/corrosion inhibitor. It performs the fol-
lowing tasks:
RAnti-corrosion protection
RAntifreeze protection
RRaising the boiling point
If the coolant has antifreeze protection down to
-35 ‡ (-37 †), the boiling point of the coolant
during operation is approximately 266 ‡
(130 †).
Service products and filling capacities343
Technical data
Z

The antifreeze concentrate/corrosion inhibitor
concentration in the engine cooling system
should:
Rbe at least 50%. This will protect the engine
cooling system against freezing down to
approximately -35 ‡ (-37 †).
Rnot exceed 55% (antifreeze protection down
to -49‡[-45 †]). Otherwise, heat will not be
dissipated as effectively.
Mercedes-Benz recommends an antifreeze/
corrosion inhibitor concentrate in accordance
with MB Specifications for Service Products
310.1.
iWhen the vehicle is first delivered, it is filled
with a coolant mixture that ensures adequate
antifreeze and anti-corrosion protection.
iThe coolant is checked with every mainte-
nance interval at a qualified specialist work-
shop.
Filling capacities
ModelCapacity
Mercedes-AMG
C 43 4MATIC11.5 US qt (10.9 l)
Mercedes-AMG
C 63
Mercedes-AMG
C 63 S12.6 US qt (11.9l)
Allot her models9.5 US qt (9.0 l)
Windshield washer system
Important safety notes
GWARNING
Windshield washer concentrate could ignite if it comes into contact with hot engine compo-
nents or the exhaust system. There is a risk of
fire and injury.
Make sure that no windshield washer con-
centrate is spilled next to the filler neck.
!Only use washer fluid that is suitable for
plastic lamp lenses, e.g. MB SummerFit or MB WinterFit. Unsuitable washer fluid could dam-
age the plastic lenses of the headlamps.
!Only MB SummerFit and MB WinterFit
washer fluid should be mixed together. The
spray nozzles may otherwise become
blocked.
Do not use distilled or de-ionized water. Other-
wise, the level sensor may give a false reading.
When handling washer fluid, observe the impor-
tant safety notes on service products
(
Ypage 340).
At temperatures above freezing:
XFill the washer fluid reservoir with a mixture of
water and windshield washer fluid, e.g. MB
SummerFit.
Add 1 part MB SummerFit to 100 parts water.
At temperatures below freezing:
XFill the washer fluid reservoir with a mixture of
water and washer fluid, e.g. MB WinterFit.
For the correct mixing ratio refer to the infor-
mation on the antifreeze reservoir.
iAdd windshield washer fluid, e.g. MB Sum-
merFit or MB WinterFit, to the washer fluid all
year round.
Climate control system refrigerant
Important safety notes
The climate control system of your vehicle is fil-
led with refrigerant R ‑134a.
The instruction label regarding the refrigerant
type used can be found on the radiator cross
member.
!Only the refrigerant R ‑134a and the PAG oil
approved by Mercedes-Benz may be used.
The approved PAG oil may not be mixed with
any other PAG oil that is not approved for
R-134a refrigerant. Otherwise, the climate
control system may be damaged.
Service work, such as refilling with refrigerant or
replacing component parts, may only be carried
out by a qualified specialist workshop. All appli-
cable regulations, as well as SAE standard J639,
must be adhered to.
Always have work on the climate control system
carried out at a qualified specialist workshop.
344Service products and filling capacities
Technical data