2018 MERCEDES-BENZ CLA COUPE brake light

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

Display messagesPossible causes/consequences andMSolutions
RadarSensorsDirtySee Operator' sMan‐ual
The radar sensor system is malfunctioning .
Possibl ecauses are:
RDirt on sensor s
RHeavy rain or snow
RWhendrivin goni nter-urban roads without traffic or infrastructure,
e.g. in desert-like area s
At least on edrivin gsystem or drivin gsafet ysystem is malfunctioning
or is temporarily unavailable :
RActive Brake Assist
RDistancePilotD ISTR ONIC
Aw arning tone also sounds.
Once th ecaus eoft heproblem is no longer present, th edrivin gand
drive safet ysystems will be available again .The display message dis-
appears.
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).
XSwitc hoff th eengine.
XClean all sensor s(Ypage 265).
XRestart theengine.
The display message disappears.
6
SRSMalfunctionSer ‐viceRequired
The restrain tsystem is malfunctioning .The 6 warning lamp also
lights up in th einstrumen tcluster.
GWARNIN G
The air bags or Emergency Tensioning Devices may either be triggered
unintentionally or, in th eevent of an accident, may no tbetriggered .
There is an increased ris kofinjury.
XVisit aqualified specialist workshop immediately.
Fo rfurther information about th erestrain tsystem, see (
Ypage 40).
6
Front Lef tMalfunc‐tionServic eRequiredorFrontRight MalfunctionServic eRequired
The restrain tsystem is malfunctioning at th efront on th eleftorr ight.
The 6 warning lamp also lights up in th einstrumen tcluster.
GWARNIN G
The air bags or Emergency Tensioning Devices may either be triggered
unintentionally or, in th eevent of an accident, may no tbetriggered .
There is an increased ris kofinjury.
XVisit aqualified specialist workshop immediately.
198Display messages
On-boardc omputer andd isplays

Display messagesPossible causes/consequences andMSolutions
If theconditi onsa re no tfulfilled ,the system is no toperating correctly.
XVisit aqualified specialist workshop immediately.
Fo rfurther information about th eOccupant Classification System, see
(
Ypage 48).
Lights
i
Vehicles wit hLED bulbs in th eligh tclusters :
The display message for th ecorre spondin glamp only appear swhen all of th eLEDsint helamp
hav efailed.
Display messagesPossible causes/consequences and MSolutions
b
Check LeftCorner ‐ing LightorCheckRight CorneringLight
The lef torright-hand cornering ligh tisdefective.
XChec kwhether you are permitte dtoreplace th ebulb yourself
(Ypage 104).
or
XVisit aqualified specialist workshop .
b
CheckLeftLowBeamorCheck Right LowBea m
The lef torright-hand low-beam headlamp is defective.
XChec kwhether you are permitte dtoreplace th ebulb yourself
(Ypage 104).
or
XVisit aqualified specialist workshop .
b
Check RearLeftTur nSignalor
Check Rea rRight
TurnSignal
The rear left-han dorrear right-hand tur nsignal is defective.
XChec kwhether you are permitte dtoreplace th ebulb yourself
(Ypage 104).
or
XVisit aqualified specialist workshop .
b
Check Front LeftTurnSignalor
Check Front Right
Tur nSignal
The fron tleft-han dorfrontright-hand tur nsignal is defective.
XChec kwhether you are permitte dtoreplace th ebulb yourself
(Ypage 104).
or
XVisit aqualified specialist workshop .
b
Check LeftMirrorTurnSignalor
Check Right Mirror
Tur nSignal
The tur nsignal in th eleft-han dorright-hand exterio rmirror is defec -
tive.
XVisit aqualified specialist workshop .
b
Check Center BrakeLamp
The high-mounte dbrak elamp is faulty.
XVisit aqualified specialist workshop .
202Display messages
On-boardcomputer andd isplays

Display messagesPossible causes/consequences andMSolutions
b
Check LeftBrakeLamporCheck RightBrake Lam p
The leftorright-hand brak elamp is defective.
XChec kwhether you are permitte dtoreplace th ebulb yourself
(Ypage 104).
or
XVisit aqualified specialist workshop .
b
CheckLeftTailandBrake Lampsor
Check Right Tai l
and Brake Lamps
The leftorright-hand tai llamp/brake lamp is defective.
XChec kwhether you are permitte dtoreplace th ebulb yourself
(Ypage 104).
or
XVisit aqualified specialist workshop .
b
CheckLeftHighBeamor Check RightHighBeam
The lef torright-hand high beam is defective.
XChec kwhether you are permitte dtoreplace th ebulb yourself
(Ypage 104).
or
XVisit aqualified specialist workshop .
b
LicensePlate Lam p
The leftorright-hand license plat elamp is faulty.
XVisit aqualified specialist workshop .
b
RearFog Lam p
The rear fog lamp is faulty.
XCheckwhether you are permitte dtoreplace th ebulb yourself
(Ypage 104).
or
XVisit aqualified specialist workshop .
b
Check Front LeftParkingLampor
Check Front Right
Parkin gLamp
The fron tleftorf rontright parking or standing lamp is defective.
XChec kwhether you are permitte dtoreplace th ebulb yourself
(Ypage 104).
or
XVisit aqualified specialist workshop .
b
Backup Light
The backup lamp is defective.
XCheckwhether you are permitte dtoreplace th ebulb yourself
(Ypage 104).
or
XVisit aqualified specialist workshop .
b
Check LeftTailLam porCheck RightTai lLamp
The lef torright-hand tai llamp is defective.
XVisit aqualified specialist workshop .
Display messages203
On-boardc omputer andd isplays
Z

Warning/
indicator
lampNSignal type
Possiblec auses/consequences and M
Solutions
!NThe yellow ABS warning lamp is lit while the engine is running.
ABS (Anti-lock Braking System) is deactivated due to amalfunction. Therefore,
BAS (Brake Assist), Active Brake Assist, ESP
®(Electronic Stability Program), the
HOLD function and hills tart assist, for example, are als odeactivated.
ATTENTION ASSIST is deactivated.
GWARNING
The brake system continues to function normally, but without the functions listed
above. The wheels coul dtherefore lock if you brake hard ,for example.
The steerability and braking characteristics may be severely affected. The braking
distance in an emergency braking situation can increase.
If ESP
®is not operational ,ESP®is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
XObserve the additionald isplay messages in the multifunction display.
XDrive on carefully.
XVisitaqualified specialist workshopi mmediately.
If the ABS control unit is faulty, there is als oapossibility that other systems ,such
as the navigation system or the automatic transmission, wil lnot be available.
!N The yellow ABS warning lamp is lit while the engine is running.
ABS is temporarily unavailable.T herefore, BAS, Active Brake Assist, ESP®,EBD
(electronic brake force distribution), the HOLD function and hills tart assist, for
example, are als odeactivated.
Possible causes are:
RSelf-diagnosi sisnot yet complete.
RThe on-board voltag emay be insufficient.
ATTENTION ASSIST is deactivated.
GWARNING
The brake system continues to function normally, but without the functions listed
above. The front and rear wheels coul dtherefore lock if you brake hard ,for exam-
ple.
The steerability and braking characteristics may be severely affected. The braking
distance in an emergency braking situation can increase.
If ESP
®is not operational ,ESP®is unable to stabilize the vehicle.
There is arisk of an accident.
XCarefully drive asuitable distance, making slight steering movements at aspeed
above 12 mph (20 km/h).
The functions mentioned above are available again when the warning lamp goes
out.
If the warning lamp is still on:
XObserve the additiona ldisplay messages in the multifunction display.
XDrive on carefully.
XVisitaq ualified specialist workshopi mmediately.
220Warning and indicator lamps in the instrument cluster
On-board computer and displays

Warning/
indicator
lampNSignal type
Possiblec auses/consequences and M
Solutions
÷åNThe yellow ESP®and ESP®OFF warning lamp sare lit while the engine is running.
ESP®,B AS, Active Brake Assist, the HOLD function and hills tart assist are not
available due to amalfunction.
ATTENTION ASSIST is deactivated.
GWARNING
The brake system continues to function normally, but without the functions listed
above.
The braking distance in an emergency braking situation can thus increase.
If ESP
®is not operational ,ESP®is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
XObserve the additiona ldisplay messages in the multifunction display.
XDrive on carefully.
XVisitaq ualified specialist workshopi mmediately.
÷åNThe yellow ESP®and ESP®OFF warning lamp sare lit while the engine is running.
ESP®,B AS, the HOLD function and hills tart assist are temporarily unavailable.
Active Brake Assist may have als ofailed.
ATTENTION ASSIST is deactivated.
Self-diagnosi sisnot yet complete.
GWARNING
The brake system continues to function normally, but without the functions listed
above.
The braking distance in an emergency braking situation can thus increase.
If ESP
®is not operational ,ESP®is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
XCarefully drive asuitable distance, making slight steering movements at aspeed
above 12 mph (20 km/h).
The functions mentioned above are available again when the warning lamp goes
out.
If the warning lamp is still on:
XObserve the additiona ldisplay messages in the multifunction display.
XDrive on carefully.
XVisitaq ualified specialist workshopi mmediately.
Warning and indicator lamps in the instrument cluster223
On-board computer and displays
Z

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
XAt coolant temperatures below 248 ‡(120 †), drive 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.
Driving systems
Warning/
indicator
lampNSignal type
Possiblec auses/consequences and M
Solutions
·NThe red distance warning lamp lights up while the vehicleisinm otion.Awarning
tone als osounds.
You are approaching avehicleoras tationary obstacl einyourline of travel at too
high aspeed.
XBe prepared to brake immediately.
XPay carefu lattention to the traffic situation. You may have to brake or take
evasive action.
Further information on the distance warning function of Active Brake Assist
(
Ypage6 2).
Warning and indicator lamps in the instrument cluster227
On-board computer and displays
Z