Navistar MaxxForce 9 Diagnostic Manual

DIAGNOSTICMANUAL
3.6.SYMPTOM5(MEDIUMDUTY):BLACKSMOKE
OVERVIEW:Hydrocarbonslipoccurswhendieselfueldoesnotfullycombustintheaftertreatment
treatmentsystemandslipsthroughtheDieselParticulateFilter(DPF)intothecleansideofthe
exhaust.Hydrocarbonslipisassociatedwithhighidletime.TheDPFshouldNOTbereplaceddueto
blackstainingintheexhaust.
NOTE–TheDPFisnot100percentefcient.Someevidenceofexhaustsootisnormal,anddoesnot
indicateamalfunctioningDPF .
WARNING
Topreventunexpectedmovementofthevehicleandpossibleseriouspersonalinjuryor
death,parkthevehicleonaat,levelsurface,applytheparkingbrake,turntheengine
offandchockthewheelstopreventthevehiclefrommovingineitherdirection.
NOTE–Beforebeginningthefollowingstep-baseddiagnostics,performallvehicleoperationalchecks
page5.
Step
ActionDecision
1
DieselParticulateFilter(DPF)SnapAccelerationT est(Quick
Test).ThisprocedurecheckstheDPFforcracksorinternal
damagewithoutremovingtheDPFfromthevehicleandisused
totestbasicfunctionalityoftheDPF .Thisistobedonepriorto
removingtheDPF .
1.Thetransmissionmustbeinneutralandtheparking
brakeapplied.
2.Startandidletheengine.
3.Rapidlysnaptheacceleratorpedalfromidletofull
throttle.Thiscanbeperformedmultipletimes.
4.Duringtheengineaccelerations,visuallycheckfora
heavyblacksmokeexitingtheexhaustpipe.
Isblacksmokevisible?
Yes:Gotostep2
No:Endofdiagnostics
Step
ActionDecision
2
RemoveandInspecttheDieselParticulateFilter(DPF)(see
ExhaustSystemmanual).AtthistimedoNOTremovethe
DieselOxidationCatalyst(DOC).
ComparetheDPFtotheDPFandDOCReuseGuidelinespage
159.
CantheDPFbereused?
Yes:InstalltheDPFandgoto
step3
No:ReplacetheDPFandgoto
step4
44
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Navistar MaxxForce 9 Specifications

General

Brand	Navistar
Model	MaxxForce 9
Category	Engine
Language	English