check engine MERCEDES-BENZ C-Class COUPE 2017 CL205 Owner's Guide

Warning/
indicator
lampNSignal type
Possiblec auses/consequences and M
Solutions
?NThe red coolant warning lamp comes on while the engine is running.
The coolant leve listoo low.
If the coolant leve liscorrect, the airflow to the engine radiator may be blocked or
the electric engine radiator fan may be malfunctioning.
The coolant is too hot and the engine is no longer being cooleds ufficiently.
XObserve the additionaldisplay messages in the multifunction display.
XPul lover and stop the vehicles afelyand switch off the engine, paying attention
to road and traffic conditions.
XSecure the vehiclea gainst rolling away(Ypage152).
XLeave the vehiclea nd keepasafe distance from the vehicleu ntil the engine has
cooledd own.
XCheck the coolant leve land add coolant, observing the warning notes
(Ypag e290).
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 is below 248 ‡
(120 †). Otherwise, the engine coul dbedamaged.
XDrive to the neares tqualified specialist workshop.
XAvoid heavy loads on the engine as you do so, e.g. driving in mountainous terrain
and stop-and-go traffic.
?NThe red coolant warning lamp comes on while the engine is running. Awarning
tone als osounds.
The coolant temperature has exceeded2 48‡(120 †). The airflow to the engine
radiator may be blocked or the coolant leve lmay be too low.
GWARNING
The engine is not being cooleds ufficiently and may be damaged.
Do not drive whe nyoure ngine 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 arisk of injury.
XObserve the additiona ldisplaym essages in the multifunction display.
XPullover and stop the vehicle safely and switch off the engine, paying attention
to road and traffic conditions.
XSecure the vehicle against rolling away (Ypag e152).
XLeav ethe vehicle and keep asafe distance from the vehicle until the engine has
coole ddown.
XCheck the coolant leve land add coolant, observing the warning notes
(Ypag e290).
XIf you have to add coolant frequently, have the engine cooling system checked.
XMake sure that the ai rsupply to the engine radiator is not blocked, e.g. by snow,
slush or ice.
254Warning and indicator lamps in the instrument cluster
On-board computer and displays

Vehicle
Warning/
indicator
lampNSignal type
Possibl ecauses/consequences and M
Solutions
ÐNThe red powe rsteering warning lamp is li twhile the engine is running.
The powe rsteering is malfunctioning.
Aw arning tone also sounds.
GWARNING
Yo uw illn eedtou semore force to steer.
There is ariskofana ccident.
XCheck whethe ryou are able to appl ythe extra force required.
If youa re abletosteer safely:
XDriveonc arefully.
XVisitaquali fied specialist workshop immediately.
If youa re unable to steer safely:
XDo not drive on.
XConsult aquali fied specialist workshop.
Warning and indicator lamps in the instrumen tcluster257
On-board computer and displays
Z

XMake sure that the windshield wipers are
turned off.
XPull release lever:on the hood.
The hood is released.
XReach into the gap, pull hood catch handle ;
up and lift the hood.
If you lift the hood by approximately 15 in
(40 cm), the hood is opened and held open
automatically by the gas-filled strut.
Closing the hood
XLower the hood and let it fall from aheight of
approximately 8in(20 cm).
XCheck that the hood has engaged properly.
If the hood can be raised slightly, it is not
properly engaged. Open it again and close it
withalittle more force.
Radiator
Do not cover up the radiator, such as with a
thermal mat or insect protection cover. The
readings of the on-board-diagnostic system may
otherwise be inaccurate. Some of these read-
ings are required by law and must be accurate at
all times.
Engine oil
Important safety notes
GWARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartmentp oses a
risk of injury.
Where possible, let the engine cool down and touch only the components described in the
following.
GWARNING
If engine oil comes into contact with hot com- ponentsint he engine compartment, it may
ignite. There is arisk of fire and injury.
Make sure that engine oil is not spilled next to
the filler neck.L et the engine cool down and
thoroughly clean the engine oil off the com-
ponentsb efore startin gthe engine.
General notes
Depending on your driving style, the vehicle
consumes up to 0.9 US qt (0.8 liters) of oil per
600 miles (1,000 km). The oil consumption may
be higher than this when the vehicle is new or if
you frequently drive at high engine speeds.
Depending on the engine, the oil dipstick may be
inad ifferent location.
When checking the oil level:
Rpark the vehicle on alevel surface
Rthe engine should be switched off for approx-
imately five minutes if the engine is at normal
operating temperature
Rall vehicles (except Mercedes-AMG C63/C
63S): if the engine is not at normal operating
temperature, e.g. if the engine was only star-
ted briefly, wait approximately 30 minutes
before carrying out the measurement
The oil level of the Mercedes-AMG C63/C 63 S
must be checked only when the engine is at
normal operating temperature.
288Engine compartment
Maintenance and care

Checking theoil level usin gthe oil dip-
stick
Example
XPull oil dipstick :out of th edipstick guide
tube.
XWipe off oil dipstick :.
XSlowly slide dipstick :intothe guide tub eto
th es top, and tak eitout again after approx-
imately 3seconds.
If th elevelisb etween MIN mark =and MAX
mark ;,theoil leve liscorrect.
XIf theoil leve lhas dropped to MIN mark =or
below, add 1. 1USqt(1.0l iter) of engineo il.
Adding engine oil
HEnvironmental note
When addingo il, takecaren otto spill any. If
oil enters th esoil or waterways, it is harmful to
th ee nvironment.
!Only use engineo ils and oil filters that have
been approved for vehicle swithas ervicesys-
tem. You can obtain alist of th eengineo ils
and oil filters tested and approved in accord- anc ewitht heMercedes-Ben zSpecifications
for Servic eProduct satany Mercedes-Benz
Servic ecenter.
Damage to th eengineore xhaust system is
caused by th efollowing:
Rusinge ngineo ils and oil filters that have not
been specifically approved for th eservice
system
Rreplacin gengineo il and oil filters after the
interval for replacements pecifiedbythe
servic esystem has been exceeded
Rusinge ngineo il additives.
!Do no tadd to omucho il. addingt oomuch
engineo il can result in damagetot heengine
or to th ecatalyti cconverter. Hav eexcess
engineo il siphoned off.
Example
XTurn cap :counter-clockwise and remove it.
XAdde ngineo il.
If th eoil leve lisatorb elow theMIN mar kon
th eo il dipstick ,add 1. 1USq t(1.0 l)of engine
oil.
XReplace cap :on the filler neck and turn
clockwise.
Ensure that the cap locks into place securely.
XCheck the oil level again with the oil dipstick
(Ypage 289).
Further information on engine oil (
Ypage 346).
Additional service products
Important safety notes
GWARNING
Certain components in the engine compart-
ment,s uch as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartment poses a
risk of injury.
Where possible, let the engine cool down and touch only the components described in the
following.
GWARNING
The cooling system is pressurized, particularly
when the motor is warm. If you open the cap,
you could be scalded if hot coolant sprays out.
There is arisk of injury.
Engine compartment289
Maintenance and care
Z

Let the engine cool down before you open the
cap. Wear gloves and eye protection. Slowly
open the cap to relieve pressure.
GWARNING
Windshield washer concentrate could ignite if it comes into contact with hot engine compo-
nents or the exhaust system. There is arisk of
fire and injury.
Make sure that no windshield washer con-
centrate is spilled next to the fillern eck.
Checking coolant level
XPark the vehicle onalevel surface.
Only check the coolant level when the vehicle
is on alevel surface and the engine has cooled
down.
XTurn the SmartKey to position 2in the ignition
lock (Ypage 131).
or
XOn vehiclesw ith KEYLESS-GO, press the
Start/Stop button twice (Ypage 131).
XCheck the coolant temperature display in the
instrument cluster (Ypage 201).
The coolant temperature must be below
158 ‡(70 †).
XTurn the SmartKey to position 0in the ignition
lock (Ypage 131).
or
XOn vehiclesw ith KEYLESS-GO, pul lthe Start/
Stop button from the ignition lock
(
Ypage 131).
XSlowl yturn cap :half aturn counter-clock-
wise to allow excess pressure to escape.
XTurn cap :further counter-clockwise and
remove it.
If the coolant is at the level of marker bar =
in the fillern eck when cold, there is enough
coolant in coolant expansio ntank ;.
If the coolant level is approximately 0.6 in
(1.5 cm) above marker bar =in the fillern eck
when warm, there is enough coolant in expan-
sion tank ;.
XIf necessary ,add coolant that has been tested
and approved by Mercedes-Benz.
XReplace cap :and turn it clockwise as far as
it wil lgo.
For further information on coolant, see
(
Ypage 347).
Adding washe rfluid to the windshield
washe rsystem
XTo open: pullcap : upwards by the tab and
open.
XAdd the premixed washer fluid.
XTo close: press cap :onto the fillern eck
until it engages.
If the washer flui dlevel drops belowt he recom-
mended minimum of 1liter, amessag eappears
in the multifunction display prompting you to
add washer flui d(
Ypage 245).
Further information on windshield washer fluid/
antifreeze (
Ypage 348).
ASSYST PLUS
Servic emessage
The ASSYST PLUS service interval display
informs you of the next service due date.
290ASSYST PLUS
Maintenancea nd care

Information on the type of service and service
intervals (see the separate Maintenance Book-
let).
You can obtain further information from 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.O bserve the notes on the engine oil
level (
Ypage 288).
The multifunction display shows aservice mes-
sage for several seconds, e.g.:
RService AinXXD ays
RServiceADue
RService AOverdue by XX Days
Depending on the operating conditions of the
vehicle,t he 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 aminor 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 periodsoft ime during
which the battery is disconnected.
Maintaining the time-dependent service sched-
ule:
XNote down the service due date displaye din
the multifunction display before disconnect-
ing the battery.
or
XAfter reconnecting the battery, subtract the
battery disconnection periodsf rom the ser-
vice date shown on the display.
Hiding aservicem essage
XPress the aor% button on the steering
wheel.
Displaying servic emessages
XSwitch on the ignition.
XUse ò on the steering wheel to call up the
list of menus.
XPress 9or: on the steering wheel to
select the Servicemenu and confirm with
a.
XPress 9or: on the steering wheel to
select the ASSYST PLUSsubmenu and con-
firm with a.
The service due date appears in the multi-
function display.
Information about Service
Resetting the ASSYST PLUS service
interval display
!If the ASSYST PLUS service interval display
has been inadvertently reset, this setting can
be corrected at aqualifieds pecialist work-
shop.
Have service work carried out as describedi n
the Maintenance Booklet. This may otherwise
leadtoi ncreased weara nd damage to the
major assemblies or the vehicle.
Aq ualifieds pecialist workshop, e.g. an author-
ized Mercedes-Benz Center, wil lreset the
ASSYST PLUS service interval display after the
service work has been carried out. You can also
obtain further information on maintenance
work, for example.
Special servic erequirements
The specifiedm aintenance interval takes only
the normal operation of the vehicle into
account. Under arduous operating conditions or
increased load on the vehicle,m aintenance
work must be carried out more frequently, for
example:
Rregular city driving with frequent intermediate
stops
Rif the vehicle is primarily used to travel short
distances
Ruse in mountainou sterrain or on poor road
surfaces
Rif the engine is often left idling for long periods
Under these or similar conditions, have, for
example ,the air filter, engine oil and oil filter
replaced or changed more frequently. Under
arduous operating conditions, the tires must be
checked more often. Further information can be obtained at aqualifieds pecialist workshop, e.g.
an authorized Mercedes-Benz Center.
ASSYST PLUS291
Maintenancea nd care
Z

XSwitch off the engine.
XRemove the SmartKey from the ignition lock.
or, in vehicles with KEYLESS-G Ostart-function
or KEYLESS ‑GO
XOpenthe driver' sdoor.
The on-board electronics now have status 0.
Thi sist he same as the SmartKey having been
removed.
XRemove the Start/Sto pbutton from the igni-
tion lock (Ypage 131).
XMake sure that the engine canno tbes tarted
via your smartphone (Ypage 134).
XMake sure that the passenger sare not endan-
gered as they do so. Make sure that no one is neart he danger are awhile awheel is being
changed .Anyone wh oisnot directl yassisting
in the wheel change should, for example,
stand behind the barrier.
XGe toutof the vehicle. Paya ttention to traffic
conditions when doing so.
XClose the driver' sdoor.
MOExtended tires( tires with run-flat
properties)
General notes
With MOExtended tire s(tires with run fla tchar-
acteristics) ,you can continu etodrive your vehi-
cle eve nifthere is atotal loss of pressure in one
or more tires. The affected tire mus tnot show
any clearl yvisible damage.
You can recognize MOExtended tire sbythe
MOExtended marking which appears on the
sidewal lofthe tire .You will find this marking
next to the tire size designation, the load-bear-
ing capacity and the speed index (
Ypage 330).
MOExtended tire smay only be used in conjunc-
tion with an active tire pressure loss warning
system or with an active tire pressure monitor.
If ap ressure loss warnin gmessage appears
in the multifunctio ndisplay:
Robserve the instructions in the display mes-
sages (Ypage 241).
Rcheck the tire for damage.
Rif driving on, observe the following notes.
The driving distance possible in run-flat mod eis
approximately 50 miles (80 km )whent he vehi-
cle is partiall ylad en. Whe nthe vehicl eisfully
laden it is approximately 19 miles (30 km). In addition to the vehicl
eload, the driving dis-
tance possible depends upon:
Rvehicl espeed
Rroa dcondition
Routsid etemperature
The driving distance possible in run-flat mode
may be reduce dbyextremedriving conditions
or maneuvers, or it can be increased through a
moderate style of driving.
The driving distance possible in run-flat mod
eis
co

unted from the moment the tire pressure loss
warning appears in the multifunction display.
You mus tnot excee damaximum speed of
50 mph (80 km/h).
Whe nreplacing one or al ltires, please observe
the following specifications for your vehicle's
tires:
Rsize
Rthe typ eand
Rthe "MOExtended" mark
If at ire hasg one flatand canno tbereplaced
with aMOExtended tire ,astandard tire may be
used as atemporary measure. Make sure that
yo uu sethe proper size and typ e(summer or
winter tire).
Vehicles equipped with MOExtended tire sare
not equipped with aTIREFIT kit at the factory. It
is therefore recommended that yo uaddit ionally
equip your vehicl ewithaT IREFIT kit if yo umount
tire sthat do not feature run-flat properties ,e.g.
winter tires. ATIREFIT kit may be obtaine dfrom
aq uali fied specialist workshop.
Important safety notes
GWARNING
Whe ndriving in emergency mode, the driving
characteristics deteriorate ,e.g. when corner-
ing, accelerating quickl yand when braking.
There is ariskofana ccident.
Do not excee dthe state dmaximum speed.
Avoi dabrup tsteering and driving maneuvers,
and driving ove robstacles (curbs ,potholes,
off-road). Thi sapplies in particula rtoaladen
vehicle.
Stop driving in emergency mod eif:
Ryouh earb anging noises.
Rthe vehicl estarts to shake.
Flat tire301
Breakdown assistance
Z

Jump-starting
For the jump-starting procedure, use only the jump-starting connection point in the engine com-
partment,consisting of apositive terminal and aground point.
All vehiclese xcept vehiclesw ithalithium-ion battery:
GWARNING
Battery acid is caustic. There is arisk of injury.
Avoid contact with skin, eyes or clothing. Do not inhale any battery gases. Do not lean over the
battery. Keep children away from batteries. Wash away battery acid immediately with plenty of
clean water and seek medical attention.
GWARNING
During charging and jump-starting, explosive gases can escape from the battery. There is arisk
of an explosion.
Particularly avoid fire, open flames, creating sparks and smoking. Ensure there is sufficient ven-
tilation while charging and jump-starting. Do not lean over abattery.
GWARNING
During the charging process, abattery produces hydrogen gas. If ashort circuit occurs or sparks
are created, the hydrogen gas can ignite. There is arisk of an explosion.
RMake sure that the positive terminal of aconnected battery does not come into contact with
vehicle parts.
RNever place metal objects or tools on abattery.
RIt is important that you observe the described order of the battery terminals when connecting
and disconnecting abattery.
RWhen jump-starting, make sure that the battery poles with identical polarity are connected.
RIt is particularly important to observe the described order when connecting and disconnecting
the jumper cables.
RNever connect or disconnectt he battery terminals while the engine is running.
GWARNING
Ad ischarged battery can freeze at temperatures below freezing point. When jump-starting the
vehicle or charging the battery, gases can escape from the battery. There is arisk of an explosion.
Allow the frozen battery to thaw out before charging it or jump-starting.
If, at low temperatures, the indicator lamps/warning lamps in the instrument cluster do not light up,
it is highly likely that the discharged battery has frozen.Int his case, you may neither charge the
battery nor jump-start the vehicle. The service life of athawed-out battery may be shorter. The
starting characteristicsc an be impaired, particularly at low temperatures. Have the thawed-out
battery checked at aqualified specialist workshop.
All vehicles:
!Avoid repeated and lengthy starting attempts. Otherwise, the catalytic converter could be
damaged by the non-combusted fuel.
308Jump-starting
Breakdown assistance

XStart the engine of the donorvehicl eand run it at idling speed.
XConnect negative terminal =of dono rbattery Bto ground point ?of your vehicl eusing the
jumper cable ,connecting the jumper cable to dono rbattery Bfirst.
XStart the engine.
XBefore disconnecting the jumper cables, le tthe engine run for several minutes.
XFirst, remove the jumper cable sfrom ground point ?and negative terminal =,then from pos-
itive clamp :and positive terminal ;.Begineacht ime at the contacts on your ownv ehiclefirst.
XClose cover Aof positive terminal :afte rremoving jumper cables.
XHave the battery checke dataqualified specialist workshop.
Jump-starting is not considered to be anorma loperating condition.
iJumpe rcable sand further information regarding jump-starting can be obtaine datany qualified
specialist workshop.
Towin gand tow-starting
Important safety notes
GWARNING
Functions relevant to safety are restricted or
no longer available if:
Rthe engine is not running.
Rthe brake system or the power steering is
malfunctioning.
Rthere is amalfunction in the voltag esupply
or the vehicle's electrical system.
If your vehicl eisbeing towed, much more
force may be necessary to stee rorbrake.
There is ariskofana ccident.
In such cases, us eatow bar. Before towing,
make sure that the steering move sfreely.
GWARNING
You can no longer stee rthe vehicl eifthe
steering wheel lock hasb eene ngaged .There
is ar iskofana ccident.
Alway sswitch off the ignition when towing the
vehicl ewithat ow cable or atow bar.
GWARNING
Whe ntowing or tow-starting another vehicle
and its weight is greate rthan the permissible
gross weigh tofyourv ehicle, the:
Rthe towing eyec ould detach itself
Rthe vehicle/trailer combination could roll-
over.
There is ariskofana ccident.
Whe ntowing or tow-starting another vehicle,
its weight shoul dnot be greate rthan the per-
missible gross weight of your vehicle.
Details on the permissible gross vehicl eweight
of your vehicl ecan be found on the vehicl eide n-
tification plate (
Ypage 343).
!Whe nCOLLISIONP REVENTION ASSIST
PLUS, DISTRONIC PLU Sorthe HOLD function
is activated, the vehicl ebrakes automatically
in certain situations.
To avoid damag etothe vehicle, deactivate
thes esystems in the following or similar sit-
uations:
Rwhen towing the vehicle
Rin the car wash
!Make sure that the electri cparking brake is
released .Ifthe electri cparking brake is faulty,
visit aquali fied specialist workshop.
!Secure the tow rop eortow ba rtothe towing
eyeo nly.Otherwise, the vehicl ecould
become damaged.
310Towinga nd tow-starting
Breakdown assistance

Tire-mounting tools should not be used near
the valve. This could damage the electronic
components.
Only have tires changed ataqualified spe-
cialist workshop.
Always observe the instructions and safety
notes in the "Mounting awheel" section
(
Ypage 336).
The wear pattern sonthe front and rear tires
differ, depending on the operating conditions.
Rotate the wheels before aclear wear pattern
has formed on the tires. Frontt ires typically
wear more on the shoulders and the rear tires in the center.
On vehicles that have the same size front and
rear wheels, you can rotatet he wheels accord-
ing to the intervals in the tire manufacturer's
warranty book in your vehicle documents. If no
warranty book is available, the tires should be
rotated every 3,000 to 6,000 miles (5,000 to
10,000k m).Earlier may be necessary, depend-
ing on the degree of tire wear. Do not change the
direction of wheel rotation.
Clean the contact surfaces of the wheel and the
brake disc thoroughly every time awheel is rota-
ted. Check the tire pressure and, if necessary,
restart the tire pressure loss warning system
(
Ypage 323) or the tire pressure monitor
(Ypage 325).
Direction of rotation
Tires with aspecified direction of rotation have
additional benefits ,e.g. if there is arisk of hydro-
planing. These advantages can only be gained if
the tires are installed corresponding to the
direction of rotation.
An arrow on the sidewall of the tire indicates its
correctd irection of rotation.
Storing wheels
Storewheels that are not being used in acool,
dry and preferably dark place. Protectt he tires
from oil, grease, gasoline and diesel.
Mounting awheel
Preparing the vehicle
XStop the vehicle on solid, non-slippery and
level ground.
XApply the electric parking brake manually.
XBring the front wheels into the straight-ahead position.
XShift the transmission to position P.
XMake sure that the vehicle level is set to "Nor-
mal" on vehicles with AIRMATIC(Ypage 172).
XSwitch off the engine.
XVehicles without KEYLESS-GO: remove the
SmartKey from the ignition lock.
XVehicles with KEYLESS-GO start-function
or KEYLESS-GO: open the driver's door.
The on-board electronics now have status 0.
This is the same as the SmartKey having been
removed.
XVehicles with KEYLESS-GO start-function
or KEYLESS-GO: remove the Start/Stop but-
ton from the ignition lock (
Ypage 131).
XMake sure that the engine cannot be started
via your smartphon e(Ypage 134).
XIf included in the vehicle equipment, remove
the tire-change tool kit from the vehicle.
XSafeguard the vehicle against rolling away.
Securing the vehicle to prevent it from
rolling away
If your vehicle is equipped with awheel chock,i t
can be found in the vehicle tool kit (Ypage 300).
The folding wheel chock is an additional safety
measure to prevent the vehicle from rolling
away,f or example when changing awheel.
336Changing awheel
Wheels and tires