Navistar N9 User Manual

1DIAGNOSTICTROUBLESHOOTINGPROCEDURES45
Step
6
Determineifvehiclehasananti-theftsysteminstalled.Decision
Lookforanti-theftpasswordswitchpanelonvehiclecenterpanel.
Doesvehiclehaveananti-theftsysteminstalled?
Yes:SeeElectricalSystem
troubleshootingGuideforAnti-Theft
Systemchecks.Afterrepairs
arecomplete,retestfororiginal
problem.
No:RepairSWBATignitionswitch
circuit.Afterrepairsarecomplete,
retestfororiginalproblem.
Step
7
DetermineifECMMPRgroundcircuitisoperatingproperly.Decision
A.Key-OnEngine-Off(KOEO)
B.RemoveECMPWRRelay
C.MeasurevoltagebetweenbatterypositiveandECMPWRrelaypin-85
Isvoltagebetweenpin85andbatterypositivewithin0.5Vofbatteryvoltage?
Yes:GotoStep10
No:GotoStep8
Step
8
DetermineifECMMPRgroundcircuitisopenDecision
A.Key-OnEngine-Off(KOEO)
B.MeasurevoltagebetweenbatterypositiveandpinC-70
IsvoltagebetweenpinC-70andbatterypositivewithin0.5Vofbatteryvoltage?
Yes:GotoStep10
No:GotoStep9
Step
9
DetermineifEngineControlModule(ECM)isoperatingproperly.Decision
A.InstallaknowngoodtestECM
B.Attempttorecreateoriginalproblem
DoesoriginalproblemoccurwithtestECM?
Yes:InstalloriginalECM.Verify
eachstepwascompletedcorrectly
andtheproperdecisionwasmade.
No:ReplaceECM.Afterrepairs
arecomplete,retestfororiginal
problem.

Navistar N9 Specifications

General

Brand	Navistar
Model	N9
Category	Engine
Language	English