User Manual

Group28
EngineControlModule(ECM)DiagnosticTrouble
Codes(DTCs)
Troubleshooting
EngineControlModule(ECM)DiagnosticTroubleCodes(DTCs)
Themanufacturerscantoolisthepreferredtoolfor
performingdiagnosticwork.Contactyourlocaldealerfor
moreinformationorvisit“www.premiumtechtool.com”.
Note:Theuseofascantoolisnecessarytoperformdiagnostic
workaswellasclearingofanydiagnostictroublecodes
(DTCs).DTC(s)cannolongerbeclearedusingthevehicles
instrumentclusterdigitaldisplayandstalkswitchcontrol.
SystemOverview
Sixelectroniccontrolunits(ECUs)areused;theenginecontrol
module(ECM),instrumentcontrolmodule(ICM),Vehicle
ElectronicControlUnit(VECU),transmissioncontrolmodule
(TCM),thegearselectorcontrolmodule(GSCM)andthe
aftertreatmentcontrolmodule(ACM).Together,thesemodules
operateandcommunicatethroughtheSAEJ1939datalinksto
controlavarietyofengineandvehiclecabfunctions.TheECM
controlssuchthingsasfueltiminganddelivery,fanoperation,
engineprotectionfunctions,enginebrakeoperation,the
exhaustgasrecirculation(EGR)valveandtheturbocharger
nozzle.TheVECUcontrolscruisecontrolfunctions,accessory
relaycontrolsandidleshutdownfunctions.TheICMprimarily
displaysoperationalparametersandcommunicatestheseto
theotherECUs.Allhavethecapabilitytocommunicateover
theSAEJ1587datalinkprimarilyforprogramming,diagnostics
anddatareporting.
Inadditiontotheircontrolfunctions,themoduleshaveon
boarddiagnostic(OBD)capabilities.TheOBDisdesignedto
detectfaultsorabnormalconditionsthatarenotwithinnormal
operatingparameters.Whenthesystemdetectsafaultor
abnormalcondition,thefaultwillbeloggedinoneorbothof
themodules’memory,thevehicleoperatorwillbeadvisedthat
afaulthasoccurredbyilluminationamalfunctionindicator
lamp(MIL)andamessageinthedriverinformationdisplay,
ifequipped.Themodulemayinitiatetheengineshutdown
procedureifthesystemdeterminesthatthefaultcoulddamage
theengine.
Insomesituationswhenafaultisdetected,thesystemwill
entera"derate"mode.Thederatemodeallowscontinued
vehicleoperationbutthesystemmaysubstituteasensor
orsignalvaluethatmayresultinreducedperformance.In
someinstances,thesystemwillcontinuetofunctionbut
enginepowermaybelimitedtoprotecttheengineandvehicle.
Diagnostictroublecodes(DTCs)loggedinthesystemmemory
canlaterberead,toaidindiagnosingtheproblemusinga
diagnosticcomputerorthroughtheinstrumentclusterdisplay,
ifequipped.WhendiagnosinganintermittentDTCorcondition,
itmaybenecessarytouseascantoolconnectedtotheSerial
CommunicationPort.
Theuseofascantoolisnecessarytoperformdiagnosticwork
aswellasclearingofanydiagnostictroublecodes(DTCs).
DTC(s)cannolongerbeclearedusingthevehiclesinstrument
clusterdigitaldisplayandstalkswitchcontrol.Additional
dataanddiagnostictestsareavailablewhenascantoolis
connectedtotheSerialCommunicationPort.
Fordiagnosticsoftware,contactyourlocaldealer.
TheECMisamicroprocessorbasedcontrollerprogrammed
toperformfuelinjectionquantityandtimingcontrol,diagnostic
faultlogging,andtobroadcastdatatootherECUs.Thefuel
quantityandinjectiontimingtoeachcylinderisprecisely
controlledtoobtainoptimalfueleconomyandreducedexhaust
emissionsinalldrivingsituations.
TheECMcontrolstheoperationoftheinjectors,enginebrake
solenoid,EGRvalve,turbochargernozzleposition,andcooling
fanclutchbasedoninputsfrommanysensorsandinformation
receivedoverthedatalinksfromotherECUs.
TheVECUandECMaredependentoneachothertoperform
theirspeciccontrolfunctions.Inadditiontoswitchandsensor
data,thebroadcastofdatabetweenmodulesalsoincludes
variouscalculationsandconclusionsthateachmodulehas
developed,basedontheinputinformationithasreceived.
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