Navistar MaxxForce DT - Graph 4: Lug down Test (Engine Speed and Tc1 Top)

DIAGNOSTICMANUAL
10.4.GRAPH4:LUGDOWNTEST(ENGINESPEEDANDTC1TOP)
1.Turbocharger1TurbineOutlet
Pressure(TC1TOP)(psi)[Blue]
2.EngineLoad(Percent)[Red]
3.AcceleratorPedalPosition1
(APP1)(Percent)[Green]
Figure29Graph4:LugDownTest(EngineSpeedandTC1TOP)
GraphAnalysis:
Thisgraphshowsanexhaustaftertreatmentsystemoperatingasdesigned(unrestricted).Thistestdoesnot
givepassorfailresults.ItonlyallowstheusertovalidateTurbocharger1TurbineOutletPressure(TC1TOP)
signalvalueunderload.HighTC1TOPwillcauselowIntakeManifoldPressure(IMP).DiagnosehighTC1TOP
concernsbeforediagnosinglowIMPconcerns.
Actions:
1.VerifyTC1TOPsignalvalueislessthan5psi(34kPa)duringLugDownT est.
NOTE–AnalyzeLugDownTestsignalvaluesonlyduringengineacceleration,andnotdecelerationor
shifting.
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