SECTION4–ENGINEOPERATION
Highidlespeedisanonadjustablefactorysetting.Thehighidle
settingdependsontheapplicationoftheengineandhasthe
followingranges:
MaxxForce
®
DT:2600rpmthrough2770rpm
MaxxForce
®
9and10:2325rpmthrough2425rpm
EXTENDEDIDLINGPERIODS
CAUTION
Topreventenginedamage,donotextendlowidle
periods.
Idlingperiodsover15minutesshouldbeavoided.Dieselengine
efciencyisimprovedwhenthecylindertemperatureremains
high.Lowtemperatureincylindersmaycausethefollowing:
•Unburnedfuelmayseepfromexhaustmanifoldgaskets
andvehicleexhaustsystemconnections.Thisseepage
hasthedarkcoloredappearanceoflubricatingoil.
•Incompletecombustionandunburnedfuelwashes
lubricatingoilfromcylindersleeves.Unburnedfuel
willbecarriedintothelubricatingoil,dilutetheoil,and
changeoilviscosity.
•Carbonformsoninternalcomponentsofturbochargers
andExhaustGasRecirculation(EGR),reducingengine
efciency.
•CarbonclogsanddamagestheDieselParticulateFilter
(DPF).
EXHAUSTAFTERTREATMENTSYSTEM
Theengineandvehicleexhaustpipingincludesan
AftertreatmentSystemtocapturesootandotherparticulates
beforetheyexittheexhaustpipe.Thesootiscapturedbythe
DieselParticulateFilter(DPF)andisperiodicallyconvertedto
carbondioxide(CO2)byaRegeneration(Regen)process.
TheRegenprocessmaytakeplaceduringvehicleoperation
(ActiveRegen).TheRegenprocesswillbetriggeredbyeithera
time-basedorasootmassbuildup-basedstrategy.
AParkedRegenprocessoccurswhenaMovingRegenisnot
possible,suchaswhenthereisnotenoughthermalenergyfor
DieselOxidationCatalyst(DOC)lightoff.Thevehicleisparked
(stationary).
WhenaRegenisrequired,theECMcommandsthe
AftertreatmentFuelInjector(AFTFI)toinjectfuelintothe
exhaustsystem.ADOCoxidizestheinjectedfueltoincrease
theexhaustgastemperatureasneededforDPFRegen.
•AParkedRegenerationwillberequestedifthePassive
Regenerationcannotbecompletedduringdriving.
•Inthiscase,alampwillbelittoalerttheoperatorto
performaParkedRegeneration.
•Theoperatormustparkthevehicleandthenperformthe
Regenasrequired.
•FollowtheParkedRegenerationprocesslistedinthe
VehicleOperatorManual.
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