check engine MERCEDES-BENZ CLA COUPE 2018 Owner's Guide

Important safety notes
GWARNING
If you operate information systems and com-
munication equipmen tintegrate dinthevehi-
cle when driving ,you may be distracte dfrom
th et raffic situation .You could also lose con-
trol of th evehicle. Ther eisariskofana cci-
dent.
Only operate this equipmen twhen th etraffic
situation permits. If you are no tsuret hatthis
is possible ,park th evehicl epayin gattention
to traffic condition sand operate th eequip-
men twhen th evehicl eiss tationary.
You must observ ethe legal requirements for th e
country in whic hyou are currentl ydriving when
operating th eon-bo ard computer.
GWARNIN G
If th einstrumen tcluste rhas faile dormal-
functioned, you may no trecognize function
restriction sinsystems relevan ttosafety. The
operating safet yofyour vehicl emay be
impaired .Ther eisar iskofana ccident.
Drive on carefully. Hav ethe vehicl echecked
at aq ualified specialist workshop immedi-
ately.
The on-board computer only shows message sor
warning sfromc ertai nsystems in th emultifunc-
tion display. You should therefor emakes ure
your vehicl eisoperating safely at all times .
If th eoperating safet yofyour vehicl eis
impaired ,pull ove rassoonasitiss afetodos o.
Contac taqualified specialist workshop.
Fo rano verview, see th einstrumen tpanel illus-
tration (
Ypage 33).
Display sand operation
Instrumen tcluster lighting
The ligh tsensor in th einstrumen tcluste rauto -
matically control sthe brightness of th emulti-
function display. In daylight, th edisplays in th e
instrumen tcluste rare no tilluminated. The lighting in th
einstrumen tcluster, in th edis-
plays and th econtrols in thevehicl einterior can
be adjusted usin gthe brightness control knob.
The brightness control knob is locate donthe
botto mleftoft heinstrumen tcluste r
(
Ypage 33).
XTurn th ebrightness control knob clockwise or
counter-clockwise.
If th eligh tswitch is set to th eÃ, Tor
L position ,the brightness is dependen t
upon th ebrightness of th eambien tlight.
Speedometer with segments
The speedometer is divided int osegments on
vehicles wit hDistance Pilot DISTRONIC.
The segments in th espeedometer indicat e
whic hspee drange is available.
RDistanc ePilot DISTRONI Cisactivated
(Ypage 151):
On eort wo segments in th eset spee drange
ligh tup.
RDistanc ePilot DISTRONI Cdetects avehicl ein
fron tmoving mor eslowly than th estored
speed:
The segments between th espee doft hevehi-
cle in fron tand th estoreds pee dligh tup.
Tachometer
!
Do no tdriveint heoverrevving range, as this
could damag ethe engine.
The red ban dinthetachometer indicates th e
engine's overrevving range.
The engin eislimite dwithin arange to protect
th ee nginew hen th ered ban disreached.
Outsidet emperatur edisplay
You should pay special attention to road condi-
tion swhen temperatures are aroun dfreezing
point.
Bea rinm indt hatthe outside temperature dis-
play indicates th etem perature measured and
does no trecord th eroad temperature.
The outside temperature display is in th emulti-
function display (
Ypage 179).
176Displaysand operation
On-boardc omputer and displays

Display messagesPossible causes/consequences andMSolutions
The yellow!warning lamp lights up and th ered F (USAonly)
or ! (Canada only) indicator lamp flashes .
It is no tpossibl etoapply th eelectric parking brak emanually.
XShift th etransmission to position B.
XVisitaqualified specialist workshop .
$(USAonly)
J(Canada only)
Check Brake Fluid
Level
There is no tenough brak efluidint hebrak efluid reservoir .
Aw arning tone sounds. The $(USAonly) or J (Canada only)
warning lamp sintheinstrumen tcluste rmay also ligh tup.
GWARNIN G
The braking effec tmay be impaired.
There is ariskofana ccident.
XPull overand stop th evehicl esafely as soo naspossible, payin g
attention to roa dand traffic conditions. Do no tcontinue driving
under any circumstances.
XSecur ethe vehicl eagainst rollin gaway (Ypage 141).
XConsult aqualified specialist workshop .
XDo notadd brak efluid .This does no tcorrect them alfunction .
#
CheckBrakePadWear
The brak epads/linings hav ereached their wear limit.
XVisit aqualified specialist workshop .
G
Inoperative
Oneorm orem ain features of th embrace system are malfunctioning .
XVisitaqualified specialist workshop .
ActiveBrakeAssistFunctionsCurrentlyLimitedSee Opera‐tor's Manual
Active Brake Assis tistemporarily inoperative.
Possibl ecauses are:
RThe radar sensor system is temporarily inoperative, e.g. due to
electromagneti cradiation emitted by nearby TV or radi ostation sor
other source sofelectromagneti cradiation .
RThe system is outside th eoperating temperature range.
RThe on-boar dvoltag eistoolow.
Whe nthe causes state dabov enol onger apply, th edisplay message
disappears.
Active Brake Assis tisoperational again .
If th edisplay message does no tdisappear :
XPull overand stop th evehicl esafely as soo naspossible, payin g
attention to roa dand traffic conditions.
XSecur ethe vehicl eagainst rollin gaway (Ypage 141).
XRestart th eengine.
Active BrakeAssist :SystemInop‐erative
Active Brake Assis tisunavailable due to amalfunction .Situation -
dependen tbraking assistanc emay also hav efailed.
XVisit aqualified specialist workshop immediately.
Display messages197
On-boardc omputer andd isplays
Z

Engine
Display messagesPossible causes/consequences andMSolutions
+
CheckCoolantLevelSee Operator'sMan‐ual
The coolant levelistoolow.
!Avoid making longj ourneys with to olittle coolant in th eengine
cooling system. The engine will otherwise be damaged.
XAdd coolant ,observing th ewarning note sbefore doings o
(Ypage 260).
If you have to ad dcoolan tfrequently:
XContac taqualified specialist workshop and have th eengine cooling
system checked.
?The fan motor is malfunctioning.
XAt coolant temperatures below 24 8‡(120 †), drive to the nearest
qualified specialist workshop.
XAvoid heavy loads on the engine as you do so, e.g. driving in moun-
tainou sterrai nand stop-and-go traffic.
?
CoolantT oo HotStop VehicleT urnEngine Off
The coolant is too hot.
Awarning tone also sounds.
GWARNING
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.
XPul lover and stop the vehicle safely and switch off the engine, pay-
ing attention to road and traffic conditions.
XSecure the vehicle against rolling away (Ypag e141).
XWai tuntil the engine has cooledd own.
XMake sure that the airsupply to the engine radiator is not blocked,
e.g. by snow, slush or ice.
XDo not start the engine again until the displaym essage goes out and
the coolant temperature is below 248 ‡(120 †). Otherwise, the
engine coul dbedamaged.
XPay attention to the coolant temperature gauge.
If the temperature increase sagain:
XVisitaq ualified specialist workshop immediately.
Under normal operating conditions and with the specified coolant
level, the coolant temperature may rise to 248 ‡(120 †).
Display messages205
On-board computer and displays
Z

Display messagesPossible causes/consequences andMSolutions
#
See Operator'sMan‐ual
The battery is no tbein gcharged.
Aw arning tone also sounds.
Possibl ecauses are:
Rad efective alternato r
Ratornp oly-V-belt
Ram alfunction in th eelectronics
!Do no tcontinue driving. The engin ecould otherwise overheat.
XPull ove rand stop th evehicl esafely and switch off th eengine, pay-
ing attention to roa dand traffic conditions.
XSecur ethe vehicl eagainst rollin gaway (Ypage 141).
XConsult aqualified specialist workshop .
#
StopVehicl eSeeOperator' sManual
The battery is no longer bein gcharged and th econditi on of charg eis
to ol ow.
Aw arning tone also sounds.
XPull ove rand stop th evehicl esafely and switch off th eengine, pay-
ing attention to roa dand traffic conditions.
XSecur ethe vehicl eagainst rollin gaway (Ypage 141).
XObserv ethe instruction sinthedisplay message #See Oper‐ator's Manual.
XConsult aqualified specialist workshop .
4
CheckEngineOilAtNextRefueling
The engin eoil level has dropped to th eminimum level.
Aw arning tone also sounds.
!Avoid lon gjou rneys wit htoo littl eengineo il. The engin ewill oth-
erwise be damaged.
XChec kthe oil level when next refueling, at th elatest (Ypage 258).
XIf necessary, add engin eoil(Ypage 259).
If th eengin eoil need stoppin gupm oreo ften:
XContac taqualified specialist workshop and hav ethe engin e
checked.
Information on approve dengineo ils can be obtained from any quali-
fie ds pecialist workshop or on th eInterne tath ttp:// bevo.mercedes -
benz.com.
æ
Fue lLevel Low
The fuel level has dropped int othe reserv erange.
XRefue lattheneares tgas station .
206Display messages
On-boardc omputer andd isplays

Warning/
indicator
lampNSignal type
Possiblec auses/consequences and M
Solutions
÷NThe yellow ESP®warning lamp flashes while the vehicleisinm otion.
ESP®or traction control has intervened because there is arisk of skidding or at
least one wheelh as started to spin.
Cruise control or Distance Pilot DISTRONIC is deactivated.
XWhen pulling away, only depress the accelerator pedalasf ar as necessary.
XEase off the accelerator pedalwhile the vehicleisinmotion.
XAdapt yourdriving style to sui tthe road and weather conditions.
XDo not deactivate ESP®.
In rare cases (
Ypage6 6),itm ay be best to deactivate ESP®.
Observe the important safety notes on ESP®(Ypage6 4).
åNThe yellow ESP®OFF warning lamp is lit while the engine is running.
ESP®is deactivated. ESP®wil lnot stabilize the vehicleifits tarts to skid or if a
wheels tarts to spin.
GWARNING
If ESP
®is switched off, ESP®is unable to stabilize the vehicle.
Further driving systems or driving safety systems are thus restricted.
There is an increased risk of skidding and an accident.
XReactivate ESP®.
In rare cases (
Ypage6 6),itm ay be best to deactivate ESP®.
Observe the important safety notes on ESP®(Ypage6 4).
XAdapt you rdriving style to sui tthe road and weather conditions.
If ESP
®cannot be activated:
XDrive on carefully.
XContact aqualified specialist workshopa nd have ESP®checked.
MNMercedes-AMG vehicles only:
The yellow SPORT handling mode warning lamp is lit while the engine is running.
SPORT handling mode is activated.
GWARNING
When SPORT handling mode is switched on, ESP
®is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
XOnly switch to SPORT handling mode in accordance with the conditions descri-
bed in the "Activating/deactivating ESP®"s ection (Ypage6 6).
222Warning and indicator lamps in the instrument cluster
On-board computer and displays

Warning/
indicator
lampNSignal type
Possiblec auses/consequences and M
Solutions
!FNF (USA only), !(Canada only): the red indicator lamp for the electric
parking brake flashes or lights up and/or the yellow warning lamp for the electric
parking brake lights up.
XObserve the additiona ldisplay messages in the multifunction display.
6N The red restraint system warning lamp is lit while the engine is running.
The restraint system is malfunctioning.
GWARNING
The air bagsorE mergency Tensioning Devices may either be triggeredu ninten-
tionally or, in the event of an accident, may not be triggered.
There is an increased risk of injury.
XObserve the additionald isplay messages in the multifunction display.
XDrive on carefully.
XContactaqualified specialist workshopa nd have the restraint system checked.
For further information about the restraint system, see (
Ypage4 0).
Engine
Warning/
indicator
lampNSignal type
Possiblec auses/consequences and M
Solutions
;NThe yellow Check Engine warning lamp lights up while the engine is running.
There may be amalfunction, for example:
Rin the engine management
Rin the fuel injection system
Rin the exhaust system
Rin the ignitio nsystem
Rin the fuel system
The emission limitv alues may be exceededa nd the engine may be in emergency
mode.
XVisitaq ualified specialist workshopi mmediately.
iIn some states, you must immediatel yvisit aqualified specialist workshopa s
soon as the yellow Check Engine warning lamp lights up. This is due to the legal
requirements in effect in these states. If in doubt, check whethers uch legal
regulations apply in the state in which you are currently driving.
æN The yellow reserve fuel warning lamp lights up while the engine is running.
The fuel levelh as dropped into the reserve range.
XRefuel at the neares tgas station.
224Warning and indicator lamps in the instrument cluster
On-board computer and displays

Warning/
indicator
lampNSignal type
Possiblec auses/consequences and M
Solutions
æNThe yellow reserve fuel warning lamp flashes while the vehicleisinm otion.
In addition, the ;Check Engine warning lamp may light up.
The fuel filler cap is not closed correctly or the fuel system is leaking.
XCheck that the fuel filler cap is correctly closed.
XIf the fuel filler cap is not correctly closed: close the fuel filler cap.
XIf the fuel filler cap is closed:visitaqualified specialist workshop.
?NThe red coolant warning lamp lights up while the engine is running and the
coolant temperature gage is at the start of the scale.
The temperature sensor for the coolant temperature gauge is malfunctioning.
The coolant temperature is no longer being monitored.T here isarisk of engine
damage if the coolant temperature is too high.
XPul lover and stop the vehicles afelyand switch off the engine, paying attention
to road and traffic conditions. Do not continue driving under any circumstances.
XSecure the vehiclea gainst rolling away(Ypage141).
XConsult aqualified specialist workshop.
Warning and indicator lamps in the instrument cluster225
On-board computer and displays
Z

Warning/
indicator
lampNSignal type
Possiblec auses/consequences and M
Solutions
?NThe red coolant warning lamp comes on while the engine is running.
The coolant levelist oo low.
If the coolant levelisc orrect, 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 cooleds ufficiently.
XObserve the additionaldisplay messages in the multifunction display.
XPullover and stop the vehicles afelyand switch off the engine, paying attention
to road and traffic conditions.
XSecure the vehiclea gainst rolling away(Ypage141).
XLeave the vehiclea nd keepasafe distance from the vehicleu ntil the engine has
cooledd own.
XCheck the coolant levela nd add coolant, observing the warning notes
(Ypage2 60).
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 levelm ay 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 e141).
XLeav ethe vehicle and keep asafe distance from the vehicle until the engine has
cooledd own.
XCheck the coolant levela nd add coolant, observing the warning notes
(Ypag e260).
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.
226Warning and indicator lamps in the instrument cluster
On-board computer and displays

XMake sure that the windshield wipers are
switched off.
XPull release lever:on the hood.
The hood is released.
XReach into the gap between the hood and the radiator trim and press hood catch lever ;to
the left.
XRaise the hood.
XPull support strut ?out of bracket A.
XLift up support strut ?and insert it into yel-
low retaining clip =.
Closing the hood
XRaise the hood slightly and, at the same time,
remove support strut ?from yellow retaining
clip =.
XSwing support strut ?down and press it into
bracket Auntil it engages.
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. Do not press the hood
closed. Open the hood again and close it with
alittle more force.
Engine oil
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
in ad 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
Rif the engine is not at normal operating tem-
perature, e.g. if the engine was only started
briefly, wait about 30 minutes before carrying
out the measurement
Checking the oil level using the oil dip-
stick
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.
258Engine compartment
Maintenance and care

XPull oil dipstick:out of the dipstick guide
tube.
XWipe off oil dipstick :.
XSlowly slide oil dipstick :into the guide tube
to the stop, and take it out again.
If the level is between MIN mark =and MAX
mark ;,the oil level is correct.
XIf the oil level has dropped to MIN mark =or
below, add 1.1 US qt (1.0 liter) engine oil.
Adding engine oil
GWARNING
Certain components in the engine compart-
ment ,such as the engine, radiator and parts
of the exhaust system, can become very hot.
Workingint he engine compartment poses 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 ,itmay
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 starting the engine.
HEnvironmenta lnote
When adding oil, take care not to spill any. If
oil enter sthe soil or waterways, it is harmful to
the environment.
!Use only engine oils and oil filters that are
approved for vehicles with aservice system. A
list of the engine oils and oil filters that have
been tested and approved in accordancew ith
Mercedes-Benz Specifications for Service
Products is availableata ny authorized
Mercedes-Benz Center.
The following cause engine failure or damage
to the exhaust system:
RUse of engine oils and oil filters that have
not been expressly approved for the service
system
RReplacement of engine oil and oil filter after
the replacement interval specified by the
service system has expired
RUse of engine oil additives
!Do not add too much oil. adding too much
engine oil can result in damage to the engine
or to the catalytic converter. Have excess
engine oil siphoned off.
Example: engine oil cap
XTurn cap :counter-clockwise and remove it.
XAdd engine oil.
If the oil level is at or below the MIN mark on
the oil dipstick ,add 1.1 US qt (1.0 liter) 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 258).
Further information on engine oil (
Ypage 317).
Engine compartment259
Maintenance and care
Z