battery MERCEDES-BENZ C CLASS 2019 Owner's Manual

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

Battery (vehicle)
Notes onthe12V battery
\nWARNINGRisk of an accident duetoworkcarried out incorrectly onthe bat‐tery
Workcarried out incorrectly onthe batterycan,forexample, leadtoa short circuit. Thiscan leadtofunctionrestrictions in safety-rel‐evant systems,forexamplethe lighting sys‐
tem, ABS (anti-lockbraking system) or ESP®
(ElectronicStability Program). The operatingsafety ofyourvehicle may berestricted.
You could lose control ofthevehicle inthefollowing situations:
Rwhen braking
Rintheevent of abruptsteering maneuversand/or whenthevehicle's speed is notadaptedtotheroad conditions
Intheevent of a shortcircuit or a simi‐lar incident, contact aqualified special‐istworkshop immediately.
Do not continue driving.
Always haveworkonthe battery carriedout at aqualified specialistworkshop.
RFurther information on ABS (page171)
RFurther information on ESP®
(page172)
For safetyreasons, Mercedes-Benzrecommendsthatyou onlyuse batteries which havebeentes‐ted and approvedforyourvehiclebyMercedes-Benz. These batteries provide increased impactprotectiontopreventvehicle occupants fromsuffering acid burns shouldthe battery be dam‐aged intheevent of an accident.
Allvehiclesexceptvehicles with a lithium-ion battery
\nWARNINGRisk ofexplosion duetoelec‐trostaticcharge
Electrostaticchargecan cause sparks whichmay ignitethe highlyflammablegas mixtureinthe battery.
Todischargeany electrostaticchargethat may havebuilt up,touchthe metalvehicle body before handlingthe bat‐tery.
The highlyflammablegas mixture is createdwhilethe battery ischarging and duringstartingassistance.
\nWARNINGDanger ofchemical burnsfromthe battery acid
Battery acid is caustic.
Avoid contact withthe skin,eyes orclothing.
Do not leanoverthe battery.
Do not inhale batterygases.
Keepchildrenawayfromthe battery.
Immediatelyrinse battery acid offthor‐oughly with plenty of cleanwater andseek medical attention immediately.
376Breakdown assistance

Allvehicles
ENVIRONMENTALNOTEEnvironmentaldamagecausedbyimproper disposal ofbatteries
Batteries contain pollutants. It isillegaltodispose ofthem withthe householdrubbish.

Dispose of batteries in anenvironmentallyresponsible manner.Takedischarged batteriestoaqualifiedspecialistworkshop ortoa collectionpointfor used batteries.
Ifyou havetodisconnectthe12V battery,con‐tact aqualified specialistworkshop.
Comply with safety notes andtakeprotectivemeasures when handling batteries.
Risk ofexplosion.
Fire, openflames and smoking areprohibited when handlingthe battery.Avoid creating sparks.
Electrolyteor battery acid is corro‐sive.Avoid contact withthe skin,eyesor clothing.Wear suitable protectiveclothing, in particulargloves, anapron and aface mask.Immediatelyrinse electrolyteor acid splashes offwith cleanwater.Consult a doctor ifnecessary.
Wear safetyglasses.
Keepchildrenaway.
Observethis Operator's Manual.
Observethefollowing ifyou do not intendtousethevehicleover anextended period of time:
RActivatestandby mode.
RAlternatively: connectthe batterytoa bat‐terycharger approvedbyMercedes-Benz orconsult aqualified specialistworkshoptodisconnectthe battery.
Notes onstarting assistance and oncharg‐ingthe12V battery
Vehicles with a lithium-ion batteryWhenchargingthe battery and duringstartingassistance, alwaysusethe jump-startconnec‐tion point inthe engine compartment.
Breakdown assistance377

NOTEDamagetothe battery fromover‐voltage
Whencharging using a batterycharger with‐out a maximumchargingvoltage,the batteryorthe on-board electronics may be damaged.
Only use batterychargerswith a maxi‐mumchargingvoltage of14.4V.
AllothervehiclesWhenchargingthe battery and duringstartingassistance, alwaysusethe jump-startconnec‐tion point inthe engine compartment.
NOTEDamagingthe batterythroughovervoltage
Whencharging using a batterycharger with‐out a maximumchargingvoltage,the batteryorthevehicle electronics may be damaged.
Only use batterychargerswith a maxi‐mumchargingvoltage of14.8V.
\nWARNINGRisk ofexplosion fromhydro‐gengas igniting
A batterygenerateshydrogengas duringthecharging process. Ifthere is a short circuit orsparksstarttoform,there is a danger ofthehydrogengas igniting.
Make surethatthe positiveterminal ofthe connected battery does not comeinto contact withvehicle parts.
Never place metal objects ortools on abattery.
When connecting and disconnectingthebattery,you must observethe descri‐bed orderforthe battery clamps.
When givingstarting assistance, alwaysmake surethatyou onlyconnect bat‐teryterminals with identical polarity.
Duringstarting assistance,you mustobservethe described orderfor con‐necting and disconnectingthe jumpercables.
Do not connect or disconnectthe bat‐teryclamps whilethe engine isrunning.
\nWARNINGRisk ofexplosion duringcharging process andstarting assistance
Duringthecharging process andstartingassistance,the battery mayrelease anexplo‐sivegas mixture.
Avoidfire, openflames, creating sparksand smoking.
Make surethatthere is sufficientventi‐lation duringthecharging process andduringstarting assistance.
Do not leanover a battery.
\nWARNINGRisk ofexplosion from a fro‐zen battery
A discharged battery may freeze attempera‐tures slightly aboveor below freezing point.
Duringstarting assistance or batterycharg‐ing, batterygas may bereleased.
Alwaysthawa frozen batteryoutfirstbeforecharging it or performingstart‐ing assistance.
378Breakdown assistance

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

Fold cover1up inthe direction ofthearrow.
Slide cover2of positive clamp3onthejump-starting connection point inthe direc‐tion ofthe arrow.
Connect positive clamp3onyourvehicletothe positive pole ofthe donor battery usingthe jumper cable/charging cable. Alwaysbegin with positive clamp3onyourownvehiclefirst.
Duringstarting assistance:starttheengine ofthe donorvehicle andrun at idlespeed.
Connectthe negative pole ofthe donor bat‐teryandground point4ofyourownvehiclebyusingthe jumper cable/charging cable.Begin withthe donor batteryfirst.
Duringstarting assistance:starttheengine ofyourownvehicle.
Duringthecharging process:startthecharging process.
Duringstarting assistance:letthe enginesrunfor several minutes.
Duringstarting assistance:before discon‐nectingthe jumper cable, switch on an elec‐trical consumer inyourownvehicle, e.g.therear windowheater or lighting.
Whenthestarting assistance/charging processis complete:
First,removethe jumper cable/chargingcable from ground point4and negativepole ofthe donor battery,then from positiveclamp3and positive pole ofthe donor bat‐
380Breakdown assistance

tery. Begin eachtime with the contacts onyourownvehiclefirst.
Afterremovingthe jumper cable/chargingcable, close cover2of positive clamp3.
Close cover1.
Further information can be obtained at aquali‐fied specialistworkshop.
Replacing the12V battery
Observethe notes onthe12V battery(page376).
Mercedes-Benzrecommendsthatyou havethe12V batteryreplaced at aqualified specialistworkshop, e.g. at an authorized Mercedes-BenzCenter.
Observethefollowing notes ifyouwanttoreplacethe batteryyourself:
RAlwaysreplace afaulty batterywith a batterywhich meetsthe specificvehiclerequire‐ments.
Thevehicle is equipped with anAGMtechnol‐ogy battery (Absorbent Glass Mat) or a lith‐ium-ion battery.Fullvehicle functionality isonly guaranteed with anAGM battery or lith‐ium-ion battery.For safetyreasons,Mercedes-Benzrecommendsthatyou onlyuse batteries which havebeentested andapprovedforyourvehiclebyMercedes-Benz.
RCarryover detachable parts, such asventhoses, elbowfitting orterminal coversfromthe battery beingreplaced.
RMake surethatthevent hose is alwayscon‐nectedtothe original opening onthe side ofthe battery.
Install anyexisting or supplied cell caps.
Otherwise,gases or battery acid couldescape.
RMake surethat detachable parts arerecon‐nected inthe sameway.
Towstarting ortowingaway
Permittedtowing methods
Mercedes-Benzrecommends transportingyourvehicle inthe case of a breakdown,ratherthantowing itaway.
Fortowing, use atowrope ortow bar with bothaxles onthe ground. Do not usetow bar sys‐tems.
NOTEDamagetothevehicle dueto tow‐ingawayincorrectly
Observethe instructions and notes ontowingaway.
Breakdown assistance381

Permittedtowing methods
Vehicle equipment/towingmethod
Bothaxles onthegroundFront axleraisedRear axleraised
Vehicles with automatic transmis‐sionYes, maximum31miles (50 km) at31mph (50 km/h)NoYes, ifthesteering wheel isfixed inthe center position with asteeringwheel lock.
4MATICvehiclesYes, maximum31miles (50 km) at31mph (50 km/h)NoNo
Towing with araised axle:towing should beperformedbyatowing company.
Towingthevehicle with bothaxles ontheground
Observethe notes onthe permittedtowingmethods (page 381).
Make surethatthe battery is connected andcharged.
Observethefollowing points whenthe battery isdischarged:
RThe engine cannotbestarted
RThe electric parking brake cannotbereleased or applied
RVehicles with automatic transmission:The automatic transmission cannot be shif‐tedtoposition\\or].
Vehicles with automatic transmission:Ifthe automatic transmission cannotbe shif‐tedtoposition\\, orthe multifunction dis‐play inthe instrument cluster does not showanything, havethevehicle transportedaway(page 384). Atowingvehicle with lift‐ing equipment isrequiredforvehicle trans‐portation.
382Breakdown assistance

Display messagesPossible causes/consequences andPPSolutions
Ifthe batterychargelevel istoo low:
Chargethe battery.
Toapply:
Switch offthe ignition.The electric parking brake is applied automatically.
Ifthe electric parking brake should not be applied, e.g. whenwashingthevehicle in an automatic carwash or whenhavingthevehicletowed, leavethe ignition switched on. This does not include havingthevehicletowed withtherear axleraised.
Ifthe electric parking brake is not applied automatically:
Switch offthe ignition and switch it back on.
Release andthen applythe electric parking brake manually (page169).
If it isstill not possibletoapplythe electric parking brake:
Visit aqualified specialistworkshop.
Where necessary,also safeguardthe parkedvehicle againstrollingaway.
Torelease:
Ifthe conditionsfor automaticrelease are fulfilled andthe electric parking brake is notreleased automatically,releasethe electric parking brake manually (page169).
Displaymessages andwarning/indicator lamps437

Display messagesPossible causes/consequences andPPSolutions
Active Lane Keeping AssistCamera View RestrictedSee Operator's Manual
Possible causes are:
Rdirt onthe windshield inthe camera'sfield of vision
Rheavyrain, snow orfog
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.
Cleanthe windshield.
Engine
Display messagesPossible causes/consequences andPPSolutions
=
See Operator's Manual
*The battery is not beingcharged.
NOTEPossible engine damage ifyou continue driving
Do not continue driving under any circumstances.
Consult aqualified specialistworkshop.
Display messages andwarning/indicator lamps457