2019 MERCEDES-BENZ C CLASS check engine

ROil leveltoo high: oil level is above2.
Ifthe oil level istoo low,add1.1 US qt(1 liter) of engine oil.
Ifthe oil level istoo high, drain offexcessengine oil. Consult aqualified specialistworkshop.
Checkingthe engine oil level usingthe on-board computer
RequirementsThe engine must havean oil level sensor. If not,the engine oil level can bechecked only withtheoil dipstick (page 354).
The engine oil level is determined during driving.Determiningthe engine oil level cantakeupto30 minutes with a normal drivingstyle andevenlonger with an active drivingstyle.
In ordertoreceivearesult asquickly as possi‐ble:
RWarmupthe engine
RParkthevehicle on a level surface
RLeavethe enginerunning at idling speed
On-board computer:
ServiceEngine Oil Level
You will see one ofthefollowing messages onthe multifunction display:
RMeasuring Engine Oil Level...: measurementofthe oil level is notyet possible.
Repeattherequest after a maximum of30 minutes driving.
REngine Oil Level OKandthe bar displayforindicatingthe oil level onthe multifunctiondisplay is green and is between "min" and"max":the oil level is correct.
REngine Oil Level Add 1.0 landthe bar displayfor indicatingthe oil level onthe multifunc‐tion display is orange and is below "min":
Add1.1 US qt (1 l) engine oil.
RReduce Engine Oil Levelandthe bar displayfor indicatingthe oil level onthe multifunc‐tion display is orange and is above"max":
Drain offexcess engine oilthat has beenadded. Consult aqualified specialistwork‐shop.
RFor Engine Oil Level Switch Ignition On:
Switch onthe ignitiontocheckthe engine oillevel.
REngine Oil Level System Inoperative: sensorfaulty or not inserted.
Consult aqualified specialistworkshop.
REngine Oil Level System Currently Unavail.:
Closethe hood.
Adding engine oil
\nWARNINGRisk of burns from hot com‐ponent parts inthe engine compartment
Certain components inthe engine compart‐ment can beveryhot, e.g.the engine,theradiator and parts oftheexhaust system.
Allowthe enginetocool down and onlytouch component parts described inthefollowing.
Maintenance and care355

\nWARNINGRisk offireand injury fromengine oil
If engine oil comes into contact withhotcomponent parts inthe engine compart‐ment, it may ignite.
Make surethat no engine oil is spillednexttothefiller opening.
Allowthe enginetocool off andthor‐oughly cleanthe engine oil from compo‐nent parts beforestartingthevehicle.
NOTEEngine damagecausedbyanincorrect oilfilter, incorrect oil or addi‐tives
Do not use engine oils or oilfilterswhich do not correspondtothe specifi‐cationsexplicitly prescribedfortheservice intervals.
Do not alterthe engine oil or oilfilter inordertoachievelongerchange intervalsthan prescribed.
Do not use additives.
Followthe instructions inthe serviceinterval displayregardingthe oilchange.
NOTEDamagecausedbyaddingtoomuch engine oil
Too much engine oil can damagethe engineorthe catalytic converter.
Haveexcess engine oilremoved at aqualified specialistworkshop.
Turncap1counter-clockwise andremoveit.
Add engine oil.
Replace cap1and turn it clockwise asfaras it will go.
Checkthe oil level again (page 354).
356Maintenance and care

Checking coolant level
\nWARNINGRisk of burns from hot com‐ponent parts inthe engine compartment
Certain components inthe engine compart‐ment can beveryhot, e.g.the engine,theradiator and parts oftheexhaust system.
Allowthe enginetocool down and onlytouch component parts described inthefollowing.
\nWARNINGDanger of burns when open‐ingthe hood
Ifyou openthe hood whenthe engine hasoverheated or during afireinthe enginecompartment,you could come into contactwith hotgases orother escaping operatingfluids.
Before openingthe hood, allowtheenginetocool down.
Intheevent of afireinthe engine com‐partment,keepthe hood closed andcallthefireservice.
\nWARNINGRisk of scalding from hotcoolant
The engine cooling system is pressurized,particularly whenthe engine iswarm. Ifyouopenthe cap,you could be scaldedbyhotcoolant spraying out.
Letthe engine cool down before open‐ingthe cap.
When openingthe cap,wear protectivegloves and safetyglasses.
Openthe cap slowlytorelease pres‐sure.
Parkthevehicle on a level surface.
Checkthe coolanttemperature display intheinstrument cluster.The coolanttemperature must be below158 °F (70 °C).
Slowly turn cap1counter-clockwisetorelieve overpressure.
Maintenance and care357

Ifthe indicator/warning lamps inthe instrumentcluster do not light up at lowtemperatures, it isverylikelythatthe discharged battery has fro‐zen. Inthis caseyou may neither jump-startthevehicle norchargethe battery.
The service life of a batterythat has beenthawed may be dramatically shortened. Thestartingcharacteristics may be impaired, espe‐cially at lowtemperatures.
It isrecommendedthatyou haveathawed bat‐terychecked at aqualified specialistworkshop.
AllvehiclesPlug-inhybrid:observethe notes inthe Supple‐ment. Otherwise,you mayfailtorecognize dan‐gers.
NOTEDamagecausedbynumerous orextended attemptstostartthe engine
Numerous orextended attemptstostarttheengine may damagethe catalytic converterduetonon-combusted fuel.
Avoid numerous andextended attemptstostartthe engine.
Observethefollowing points duringstartingassistance and whenchargingthe battery:
ROnly use undamaged jumper cables/charg‐ing cables with a sufficient cross-section andinsulatedterminal clamps.
RNon-insulated parts oftheterminal clampsmust not come into contact withother metalparts whilethe jumper cable/charging cableis connectedtothe battery/jump-startcon‐nection point.
RThe jumper cable/charging cable must notcome into contact withany parts which maymovewhenthe engine isrunning.
RAlways make surethat neitheryou northebattery is electrostaticallycharged.
RKeepawayfromfireand openflames.
RDo not leanoverthe battery.
Observethe additionalfollowing points whenchargingthe battery:
ROnly use batterychargerstested andapprovedfor Mercedes-Benz.
RReadthe batterycharger's operating instruc‐tions beforechargingthe battery.
Observethe additionalfollowing points duringstarting assistance:
RStarting assistance may only be providedusing batteries with a nominalvoltage of12V.
RThevehicles must nottouch.
RGasoline engine:Onlyacceptstarting assis‐tance ifthe engine andexhaust system arecold.
Starting assistance andchargingthe12 Vbattery
Requirements:RThevehicle is secured withthe electric park‐ing brake.
RAutomatic transmission:The transmissionis in position].
RThe ignition and all electrical consumers areswitched off.
RThe hood is open.
Breakdown assistance37 9

Display messagesPossible causes/consequences andPPSolutions
(Canada only)
Check Brake Fluid Level
Consult aqualified specialistworkshop.
Do not add brakefluid.
Pullover andstopthevehicle safely as soon as possible, paying attentiontoroad and traffic conditions. Do notcontinue driving under any circumstances.
Do not add brakefluid.
Consult aqualified specialistworkshop.
Radar Sensors Dirty SeeOperator's Manual
*Theradar sensor system is malfunctioning.Possible causes are:
RDirt onthe sensors
RHeavyrain or snow
RExtended country driving withoutother traffic, e.g. inthe desert
Driving systems and driving safety systems may be malfunctioning ortemporarily unavailable.
Oncethe cause ofthe problem is no longer present, driving systems and driving safety systems will beavailableagain.
Ifthe display message does not disappear:
Pullover andstopthevehicle safely as soon as possible, paying attentiontoroad and traffic conditions.
Clean all sensors (page 364).
Restartthe engine.
440Displaymessages andwarning/indicator lamps

Display messagesPossible causes/consequences andPPSolutions
Active Brake Assist Func-tions Currently Limited SeeOperator's Manual
*Vehicles withthe Driving AssistancePackage:Active Brake Assistwith cross-traffic function, EvasiveSteering
Assist or PRE‑SAFE®PLUS aretemporarily unavailable or only partiallyavailable.
Vehicles withoutthe Driving Assistance package:Active Brake Assististemporarily unavailable.
The ambient conditions are outsidethe system limits (page175).
Drive on.As soon asthe ambient conditions are withinthe system limits,the system will becomeavailable again.
Ifthe display message does not disappear,stopthevehicle while paying attentiontoroad and traffic conditionsandrestartthe engine.
u
SRS Malfunction ServiceRequired
*Therestraint system isfaulty (page 34).
\nWARNINGRisk of injuryorfatal injury duetoa malfunction intherestraint system
Iftherestraint system is malfunctioning,restraint system components may be triggered unintentionally ormight not be triggered at all intheevent of an accident. This may affectthe EmergencyTensioning Device orairbag,forexample.
Havetherestraint systemchecked andrepaired immediately at aqualified specialistworkshop.
Detection of arestraint system malfunction:
RTheurestraint systemwarning lamp does not light up whenthe ignition is switched on.
RTheurestraint systemwarning lamp lights up continuously orrepeatedly during a journey.Visit aqualified specialistworkshop immediately.
Displaymessages andwarning/indicator lamps447

Display messagesPossible causes/consequences andPPSolutions
Blind Spot Assist Inopera-tive
Visit aqualified specialistworkshop.
Active Parking Assist andPARKTRONIC InoperativeSee Operator's Manual
*ActiveParking Assist andParking AssistPARKTRONIC are malfunctioning.
Stopthevehicle, paying attentiontoroad and traffic conditions, andrestartthe engine.
Ifthe display message continuestobe displayed, consult aqualified specialistworkshop.
Active Blind Spot AssistCurrently Unavailable SeeOperator's Manual
*Active Blind Spot Assististemporarily unavailable.
The system limits havebeenreached (page219).
Drive on.Oncethe cause ofthe problem is no longer present,the system will beavailable again.
Ifthe display message does not disappear,stopthevehicle while paying attentiontoroad and traffic conditionsandrestartthe engine.
Active Steering Assist Cur-rently Unavailable SeeOperator's Manual
*ActiveSteering Assist istemporarily unavailable.
The ambient conditions are outsidethe system limits (page189).
Drive on.As soon asthe ambient conditions are withinthe system limits,the system will becomeavailable again.
If necessary,cleanthe windshield inthe camera'sfield of vision.
Checkthe tire pressure if necessary.
450Display messages andwarning/indicator lamps

Display messagesPossible causes/consequences andPPSolutions
Pullover andstopthevehicle safely and switch offthe engine, paying attentiontoroad and traffic conditions.
Consult aqualified specialistworkshop.
=
Stop Vehicle Leave EngineRunning
*The batterychargelevel istoo low.
Pullover andstopthevehicle safely as soon as possible, paying attentiontoroad and traffic conditions. Do notcontinue driving under any circumstances.
Leavethe enginerunning.
Wait untilthe display message disappears before pullingaway.
Check Coolant Level SeeOperator's Manual
*The coolant level istoo low.
NOTEEngine damageduetoinsufficient coolant
Avoid long journeyswith insufficient coolant.
Add coolant (page 357).
=
12 V Battery See Opera-tor's Manual
*The engine is off andthe batterychargelevel istoo low.
Switch off electrical consumersthat are notrequired.
Leavethe enginerunningfor afew minutes, or drivefor a longer distance.The battery willcharge.Ifthe message appears whilethe engine isrunning,this indicates an on-board electrical system malfunction.
Visit aqualified specialistworkshop.
458Display messages andwarning/indicator lamps