Navistar N10

1DIAGNOSTICTROUBLESHOOTINGPROCEDURES41
9.0-EngineCompressionBrakeOperationalCheckoutProcedure
Step
1
Performpreliminaryoperationalcheckoutprocedure.Decision
Didyouperform1.0PreliminaryVehicleOperationalCheckoutProcedure?Yes:GotoStep2
No:Goto1.0PreliminaryVehicle
OperationalCheckoutProcedure
(page23).
Step
2
CheckforrelatedDiagnosticTroubleCodes(DTC).Decision
UsingElectronicServiceTool(EST)withServiceMaxx™,checkDTClistfor:
•SPN191TransmissionOutputShaftSpeed(TOSS)VehicleSpeedSensor
(VSS)
•SPN597EngineCompressionBrakeSwitch
•SPN4287EngineCompressionBrakePressure(ECBP)
DoesESTDTClisthaveanyoftheabovelistedSPN?
Yes:GotoFaultCodeDiagnostics
forappropriateSPN.
No:Perform0to60MPHT est
(page2236)whilesymptomis
occuring,activateenginebrakeand
deactivateenginebrake.Goto
Step3
Step
3
Determineifenginecompressionbrakeisoperating,orisengagedwhen
notcommandedOn.
Decision
Review0to60snapshot
Doesenginebrakeactivateanddeactivateproperlywhencommanded?
No,enginebrakedoesnotactivate:
Goto9.1EngineCompression
BrakeInoperative(page126).
No,enginebrakedoesnot
disengagewhencommandedOff:
Goto9.2EngineCompression
BrakeEngagedWhenNot
Commanded(page129).
Yes:Reviewoperatorcomplaint