SECTION1–ENGINESYSTEMS
Crankshaft
Thecrankshafthassevenmainbearingswithforeandaftthrust
controlledattherearbearing.Onefracturedcapconnectingrod
isattachedateachcrankshaftjournal.Thepistonpinmoves
freelyinsidetheconnectingrodandpiston.Pistonpinretaining
ringssecurethepistonpininthepiston.Therearoilsealcarrier
ispartoftheywheelhousing.
CylinderHead
Thecylinderheadhasfourvalvespercylinderwithcentrally
locatedfuelinjectorsdirectingfueloverthepistons.This
congurationprovidesimprovedperformanceandreduces
emissions.
Thefuelinjectionsystemiselectro-hydraulic.Thesystem
includesanunder-valve-coverhigh-pressureoilmanifold,fuel
injectors,andahigh-pressureoilpump.Theinjectorsare
installedinthecylinderhead,underthevalvecoverandunder
thehigh-pressureoilmanifold.
Thewatersupplyhousingservesasthemountingbracketfor
therefrigerantcompressor.Mountingcapabilitiesforadual
refrigerantcompressorareavailableasanoption.Thepad
mountingdesignofthealternatorandrefrigerantcompressor
bracketsprovideeasyremovalandimproveddurability.
ElectronicControlSystem
AnEngineControlModule(ECM)monitorsandcontrolsengine
performancetoensuremaximumperformanceandcompliance
withEPAemissionsrequirements.
Heavy-DutyOn-BoardDiagnostics(HD-OBD)isaU.S.
Governmentmandatedstandardforall2013andlaterClass4
andabovevehicleswithaGrossVehicleWeightRating(GVWR)
of14,001poundsormore.TheHD-OBDsystemmonitorsthe
engineandaftertreatmentsystemstoverifytheyareoperating
withinemissionslimits.Ifanemissionsfaultislogged,the
MalfunctionIndicatorLamp(MIL)willilluminateandoneormore
faultcodeswillbeset.
TheHD-OBDsystemoperatessimilarlytopreviouspowertrain
controlsystemsbystoringfaultcodesandturningontheMIL.If
theproblemthatcausedthefaultgoesaway,thecodewillclear
andtheMILwillgooutaftercertainoperatingconditionshave
beenmet.Thismaytakeseveraltimesoperatingthevehicle.
TheCrankshaftPosition(CKP)sensorandtheCamshaft
Position(CMP)sensorareusedbytheECMtocalculaterpm,
fueltiming,fuelquantity,anddurationoffuelinjection.
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