1DIAGNOSTICTROUBLESHOOTINGPROCEDURES43
11.0-ECMLossofCommunication
Overview
DiagnoseEngineControlModule(ECM)willnotcommunicatewithElectronicServiceTool(EST).
PossibleCauses
•TheftDeterrentSystem
•PublicCANCircuit(terminatingresistor,etc.)
•AnyfailedmoduleonPublicCAN
•PowerandgroundcircuitstoDiagnosticConnector
•EngineControlModule(ECM)powercircuit(ECMfuse,ECMPWRRelay,etc.)
•ECMgroundcircuit
•LowBatteryVoltage
•FaultyECM
TestProcedure
Step
1
Performpreliminaryoperationalcheckoutprocedure.Decision
Didyouperform1.0PreliminaryVehicleOperationalCheckoutProcedure?Yes:GotoStep2
No:Goto1.0PreliminaryVehicle
OperationalCheckoutProcedure
(page23).
Step
2
DetermineifElectronicServiceTool(EST)isworkingproperly.Decision
A.Key-OnEngine-Off(KOEO)
B.ConnectESTwithServiceMaxx™toasecondvehicleandlogin.
DoesESTcommunicateproperlywithsecondvehicle?
Yes:GotoStep3
No:RepairEST .Afterrepairs
arecomplete,retestfororiginal
problem.