Navistar MaxxForce 13 - SYMPTOM 3 (MEDIUM DUTY): SPN 3719 OR SPN 3936 ACTIVE ONLY OR FREQUENT REGENS (MORE THAN ONE PARKED REGEN PER DAY)

DIAGNOSTICMANUAL
Step
ActionDecision
8
DoOnboardFilterCleanlinessTest(OBFCT)toclearactive
aftertreatmentfaultcode(s).UsingElectronicServiceT ool(EST)
withServiceMaxx™software,gotoT ests>KOERAftertreatment
Tests>OnboardFilterCleanlinessT est.WhileOBFCTisrunning,
checkthefollowingcomponentsforexhaustleaks,andverifyall
fasteners,brackets,andclampsaresecureandundamaged:
•LowPressure(LP)turbochargeroutletpipe
•ExhaustBackPressureValve(EBPV)
•FlexiblemeshpipetoDOCinlet
•InlettoDOC
Wereallcomponentsfreeofexhaustleaks,andallfasteners,
brackets,andclampssecureandundamaged?
Yes:Gotostep9
No:Repairexhaustleak
orrepairfailedfastener,
bracket,orclamp.After
repairsarecomplete,go
tostep9.
Step
ActionDecision
9
CheckforafailedAirManagementSystem(AMS)actuator.
1.UsingESTwithServiceMaxx™software,gotoT ests
>LoadTestSpecicSessionandverifyLoadT est
SpecicSessionisunchecked.
2.GotoSessions>Performanceandselecttherecord
snapshoticonfromthetoolbar.
3.GotoT ests>KOERTests>AirManagementT est.
WhenAirManagementT estiscomplete,stoprecording.Use
theplaybackfeatureinServiceMaxx™,andgraphthefollowing
signalvalues:
SignalValues:
•MassAirFlow(MAF)meanvalue
•IntakeManifoldPressure(IMP)
•ExhaustGasRecirculation(EGR)valveposition
DoessnapshotmatchGraph1orGraph2page51?
Graph1:Gotostep10A
Graph2:Diagnoseand
repairfailedactuator
(SeePerformance
Diagnosticssection
inEngineDiagnostic
Manual).Afterrepairs
arecomplete,retestfor
originalproblem.
20
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