2019 MERCEDES-BENZ C CLASS engine overheat

Do not switch offthe ignition while driv‐ing.
\nDANGERRisk offatal injuries duetoexhaustgases
Combustion engines emit poisonousexhaustgases such as carbon monoxide. Inhalingtheseexhaustgases is hazardoustohealthand can leadtopoisoning.
Never leavethe enginerunning in anenclosed space without sufficientventi‐lation.
\nWARNINGRisk of skidding and of anaccident duetoshifting down on slipperyroad surfaces
Ifyou shift down on slipperyroad surfacestoincreasethe engine braking effect,the drivewheels may lose traction.
Do not shift down on slipperyroad sur‐facestoincreasethe engine brakingeffect.
\nDANGERRisk offatal injury duetopoi‐sonousexhaustgases
Ifthetailpipe is blocked or sufficientventila‐tion is not possible, poisonousexhaustgasessuch as carbon monoxide may enterthevehi‐cle. This isthe case ifthevehiclegetsstuckin snow,forexample.
Keepthetailpipe andthe area aroundthevehicle free from snow whentheengine orthestationary heater arerun‐ning.
Open a window onthe windward side ofthevehicletoensure an adequate sup‐ply of fresh air.
\nWARNINGRisk of accident and injuryduetobeing underthe influence of alco‐hol and drugs while driving
Driving when underthe influence of alcoholand/or drugs is anextremelydangerouscombination. Even smallquantities of alcoholor drugs may affectyourreflexes, perceptionand judgment.
The probability of a serious orevenfatal acci‐dent greatly increases ifyou drive whenunderthe influence of alcohol or drugs.
Do not drink alcohol ortakedrugs whiledriving, and do not allow anyonetodrive who has been drinking alcohol ortaking drugs.
\nWARNINGRisk of accident duetothebrake systemoverheating
Ifyou leaveyourfootonthe brake pedalwhen driving,the brake system mayover‐heat.
This increasesthe braking distance andthebrake system mayevenfail.
Never usethe brake pedal as afootrest.
Do not depressthe brake pedal andtheaccelerator pedal atthe same timewhile driving.
Driving and parking14 9

1Cruise control is selected
2Speed is saved, cruise control is deactivated
3Speed is saved, cruise control is activated
The segments betweenthestored speed andthe end ofthe segment display light up inthe speedometer.
System limitationsCruise control may be unabletomaintainthestored speed on uphill gradients. Thestoredspeed isresumed whenthe gradientevens out.
Change into a lowergear in good time on longandsteep downhill gradients.Takeparticularnoteofthis when driving a ladenvehicle. By
doing so,you will make use ofthe engine's brak‐ing effect. Thisrelievesthe load onthe brakesystem and preventsthe brakes fromoverheat‐ing andwearingtooquickly.
Do not use cruise control inthefollowing situa‐tions:
RIn traffic situations whichrequire frequentchanges of speed, e.g. in heavy traffic, onwindingroads.
ROn slipperyroads.Accelerating can causethe drive wheelstolose traction andthevehicle couldthen skid.
RIfyou are driving when visibility is poor.
Operating cruise control
\nWARNINGRisk of accident duetostoredspeed
Ifyou call upthestored speed andthis islowerthanyour current speed,thevehicledecelerates.
Takeinto accountthe traffic situationbefore calling upthestored speed.
Requirements:RESP®must be activated, but not intervening.
RThe driven speed is at least15mph(20 km/h).
RThe transmission is in position[.
Toactivate cruise control:pressrockerswitch1up.
18 2Driving and parking

The segments on speedometer1indicatethesystemstatusforthefollowing:
RCruise control (page181)
RActive Distance AssistDISTRONIC(page183)
NOTEEngine damageduetoexcessivelyhigh engine speeds
The engine will be damaged ifyou drive withthe engine intheoverrevvingrange.
Do not drive with the engine intheover‐revvingrange.
The fuel supply is interruptedtoprotecttheengine whenthered mark ontachometer3(overrevvingrange) isreached.
During normal operating conditions, coolanttemperature display4mayrisetotheredmark.
\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.
Overview ofthe buttons onthesteeringwheel
1¤Back/Home button (press and hold),on-board computer
2Touch Control, on-board computer
3Control panelfor cruise control orActiveDistance AssistDISTRONIC
4Control panelfor multimedia system:
£Voice Control System
ßDisplaysfavorites
VOL: control knob, adjuststhevolume orswitchesthe sound offc(press)
aMakes/accepts a call
Instrument Display and on-board computer227

Rfrequent operation in mountainousterrain oron poorroad surfaces
Rwhenthe engine is often leftidlingfor longperiods
Roperation in particularly dusty conditionsand/or if air-recirculation mode is frequentlyused
Inthese or similar operating conditions, havetheinterior airfilter, engine air cleaner, engine oiland oilfilteretc.changed more frequently. Thetires must bechecked more frequently ifthevehicle is operated under increased loads.Fur‐ther information can be obtained at aqualifiedspecialistworkshop.
Battery disconnection periods
The ASSYST PLUS service interval displaycan only calculatethe service due datewhenthe batteryis connected.
Notedownthe service due date displayed onthe instrument display before disconnectingthe battery (page 351).
Engine compartment
Opening/closingthe hood
\nWARNINGRisk of accident ifthe enginehood is unlatched while driving
An unlocked engine hood may open up whenthevehicle is in motion and blockyour view.
Never unlatchthe engine hood whiledriving.
Beforeevery trip, ensurethattheengine hood is latched.
\nWARNINGRisk of accident and injurywhen opening and closingthe enginehood
When opening or closingthe engine hood, itmay suddenly drop intothe end position.
There is arisk of injuryfor anyone intheengine hood'srange of movement.
Only open or closethe engine hoodwhenthere are no persons intheengine hood'srange of movement.
\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 injuryduetomovingparts
Certain components inthe engine compart‐ment may continuetomoveor suddenlymoveagaineven afterthe ignition has beenswitched off, e.g.the coolerfan.
Makesure ofthefollowing before performingtasks inthe engine compartment:
Switchthe ignition off.
352Maintenance 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

Continue turning cap1counter-clockwiseandremoveit.
The coolant level is correct:
RIfthe engine is cold, uptomarker bar2
RIfthe engine iswarm, upto0.6 in (1.5 cm)over marker bar2
If necessary,add coolantthat has beenapprovedbyMercedes-Benz.RFurther information on coolant(page 429).
Addingwasher fluidtothe windshieldwasher system
\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.
\nWARNING‑ Risk offireand injury fromwindshieldwasher concentrate
Windshieldwasher concentrate is highlyflammable. It could ignite if it comes intocontact withhot engine component parts ortheexhaust system.
Make surethat no windshieldwasherconcentrate spills out nexttothefilleropening.
Removecap1bythetab.
Addwasherfluid.
Keepingthe air-water duct free
Keepthe area betweenthe hood andthewindshield free of deposits, e.g. ice, snowand leaves.
358Maintenance and care

Rat aqualified specialistworkshop
Coolant
Notes on coolantObservethe notes on operatingfluids(page 425).
\nWARNING‑ Risk offireand injury fromantifreeze
If antifreeze comes into contact withhotcomponent parts inthe engine compart‐ment, it may ignite.
Allowthe enginetocool down beforeadding antifreeze.
Makesurethat no antifreeze spills outnexttothefiller opening.
Thoroughly clean off any antifreezefrom component parts beforestartingthevehicle.
NOTEDamagecausedbyincorrect cool‐ant
Only add coolantthat has been pre‐mixed withtherequired antifreeze pro‐tection.
Information on coolant isavailable atthefol‐lowing locations:
RInthe Mercedes-Benz SpecificationforOperating Fluids310.1
-Athttp://bevo.mercedes-benz.com
-Inthe Mercedes-Benz BeVo app
RAtaqualified specialistworkshop
NOTEOverheating at high outsidetem‐peratures
If an inappropriate coolant is used,theengine cooling system is not sufficiently pro‐tected againstoverheating and corrosion athigh outsidetemperatures.
Always use coolant approvedbyMercedes-Benz.
Observethe instructions intheMercedes-Benz Specificationsfor Oper‐ating Fluids310.1.
Havethe coolantregularlyreplaced at aqualifiedspecialistworkshop.
The proportion of corrosion inhibitor/antifreezeconcentrate inthe engine cooling system shouldbe:
Ra minimum of 50% (antifreeze protectiondowntoapproximately -35 °F (-37 °C))
Ra maximum of 55% (antifreeze protectiondownto-49 °F (-45 °C))
Coolant capacity
ModelCapacity
All models9.1 US qt (8.6 liters)
Notes on windshieldwasher fluid
Observethe notes on operatingfluids(page 425).
Technical data429

Display messagesPossible causes/consequences andPPSolutions
Transmission MalfunctionStop
Pullover andstopthevehicle safely as soon as possible, paying attentiontoroad and traffic conditions.
Switchthe transmissiontoposition].
Consult aqualified specialistworkshop.
N Permanently Active Riskof Rolling Away
*Whilethevehicle isrolling or whileyou are driving,the transmission has been shiftedtoposition\\.
Depressthe brake pedaltostop and, whenthevehicle isstationary,shiftthe transmissiontoposition].
Tocontinueyour journey,shiftthe transmissiontoposition[or^.
Stop Vehicle Leave EngineRunning Wait TransmissionCooling
*The transmission isoverheating. Pullingawaymay betemporarily impaired or not possible.
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.
To Deselect P or N,Depress Brake and StartEngine
*You haveattemptedtoshiftthe transmission out of position]or\\into another transmission position.
Depressthe brake pedal.
Startthe engine.
Apply Brake to Shift from'P'
*You haveattemptedtoshiftthe transmission out of position]and into another transmission position.
Depressthe brake pedal.
Service Required Do NotShift Gears Visit Dealer
*The transmission is malfunctioning. The transmission position can no longer be shifted.
464Display messages andwarning/indicator lamps