Navistar N10

461DIAGNOSTICTROUBLESHOOTINGPROCEDURES
Step
10
DetermineifpowercircuitstotheECMareworkingproperly.Decision
A.Key-OnEngine-Off(KOEO)
B.MeasurevoltagebetweenbatterygroundandpinsC-1,3and5
ArepowercircuitsbetweenpinsC-1,3and5andbatterygroundwithin0.5Vof
batteryvoltage?
Yes:GotoStep11
No:DiagnoseandrepairECM
powercircuit(40Afuse,ECM
PWRRelay,etc.).Afterrepairs
arecomplete,retestfororiginal
problem.
Step
11
DetermineifPublicCANcircuitsbetweenECMandDiagnosticConnector
areOpenorhavehighresistance.
Decision
A.KeyOff
B.DisconnectBatteries
C.Measureresistancebetween9-pinDiagnosticConnectorpin-Dand
ECMpinC-62(CAN-L)
D.MeasureresistancebetweenDiagnosticConnectorpin-CandECMpin
C-61(CAN-H)
Aremeasuredresistances5ohmsorless?
Yes:GotoStep12
No:Repairopenorhighresistance
inPublicCANcircuit(s).After
repairsarecomplete,retestfor
originalproblem.
Step
12
MeasureresistancebetweenPublicCANcircuits.Decision
MeasureresistancebetweenDiagnosticConnectorpin-Candpin-D.
IsresistancebetweenDiagnosticConnectorpin-Candpin-Dapproximately60
ohms?
Yes:GotoStep14
No:GotoStep13