汽车专业英语PPT课件-section 2ppt课件Chapter 7-1 47 2

Chapter7CommonSpecialServiceToolsandEquipments,7.1FunctionsofDiagnosticEquipments7.2OperationofOTCEnhancedMonitorscantool,Chapter7CommonSpecialServiceToolsandEquipments7.1FunctionsofDiagnosticEquipments,NewWords,Chapter7CommonSpecialServiceToolsandEquipments7.1FunctionsofDiagnosticEquipments,NewWords,Chapter7CommonSpecialServiceToolsandEquipments7.1FunctionsofDiagnosticEquipments,7.1.4ScanToolsAscantool(orscanner)isprobablythemostfamiliartooltoanyoneworkingwithtodayscomputerizedsystems.Figures725showsatypicalscantool.However,itisimportanttorecognizethedistinctabilitiesofascantool.PurposeCodePulling.AscannersabilitytopullcodesincludesbothpullingDTCsfromacomputersmemoryandcausingthecomputertoperformaself-testofthesystemanddisplaytheresultingDTCs.,Chapter7CommonSpecialServiceToolsandEquipments7.1FunctionsofDiagnosticEquipments,Figure725AtypicalscantoolthatcanbeusedtoretrievedatastreaminformationfromthePCM.,FunctionalTests.ScantoolscanalsobeusedtoperformfunctionaltestsSomescantoolmanufacturersrefertothesetestsasspecialtests.Theprimaryandbest-knownfunctionaltestistheactivecommandmode,inwhichthescantoolisabletocommandon-boardcontrolmodulestoperformcertainactions,suchasenergizingacoolingfanrelayoracanisterpurgeventsolenoid.Acommonuseofsuchatestistohelpthetechnicianquicklynarrowaproblemdowntotheinputsideortheoutputsideofthecomputer.Forexample,iftheelectriccoolingfandoesnotcomeonduringnormalvehicleoperation,resultinginanover-heatingconditionoftheengine,ascantoolmaybeusedtocommandthePCMtoenergizethecoolingfanrelay.,Chapter7CommonSpecialServiceToolsandEquipments7.1FunctionsofDiagnosticEquipments,Ifthecoolingfanthenruns,theoutputsideofthecomputerhasbeeneliminatedasapossiblefaultandthetechnicianknowsthattheproblemislikelyontheinputsideeitheracoolanttemperaturesensororitsassociatedwiring.However,ifthecoolingfandoesnotrunduringthistest,thenthetechnicianknowsthattheproblemislikelyontheoutputsideofthecomputerandcanproceedbytestingthecoolingfanrelay,thecoolingfanmotor,andtheassociatedwiring.Anotherpurposeofthistestissimplytoprovideaneasymethodofenergizinganactuatorwhentheneedarisesforthesakeofothertestingprocedures.Forexample,thetechnicianmayuseascantooltocommandthePCMtoenergizethenormallyopencanisterpurgeventsolenoidwhenusingaleaktestertotesttheevaporativesystemforleaks.,Chapter7CommonSpecialServiceToolsandEquipments7.1FunctionsofDiagnosticEquipments,Thisclosesthesolenoidandthusenablesthesystemtoholdpressure.Thisabilityeliminatestheneedforenergizingthesolenoidmanuallyusingjumperwiresinordertoleaktestthesystem.DataStream.Scantoolscanreaddatastreaminformationfromtheon-boardcomputers.Thisinformationincludesthecomputersinterpretationofinputsensorvalues,includingboththeperceivedvoltageandtheinterpretedvalue.Forexample,theenginecoolanttemperature(ECT)informationmaybedisplayedasavoltage(0.62V)andastheinterpretedtemperaturethatitrepresents(205For96C).Thescandataalsoshowsthecomputersintendedoutputcommands.Itisalwaysagoodideatocheckwhethertheintendedcommandsareactuallybeingcarriedout.,Chapter7CommonSpecialServiceToolsandEquipments7.1FunctionsofDiagnosticEquipments,Scantoolwillalsodisplayotherpiecesofinformationfromthecomputersmemory.ThisincludesinformationsuchasfueltrimvaluesandPROMIDnumbers.Scandatamaybecustomizedonmanyscantools.ThisabilityallowsthetechniciantoselectonlytheparameterIDsthathe/shewishestolookat.ThisspeedsupthescantoolsupdateratebecausethePCM(orothercontrolmodule)nolongerhastocommunicatealltheavailableinformationtothescantool.Manyscantoolsprovideadditionalfeaturessuchasadatacapturemode(sometimescalledasnapshotormoviemode)foruseinidentifyingcausesofintermittentsymptoms.Whenattemptingtoverifyanintermittentproblem,thismodemaybeusedtocapturedatawhileroadtestingthevehicle.,Chapter7CommonSpecialServiceToolsandEquipments7.1FunctionsofDiagnosticEquipments,Whenthesymptomisfelt,thisdatacanbefrozenwithinthescantool,anditcanbereviewedlater,framebyframe,whilewatchingtheinput/outputvaluesatthepointwherethesymptomoccurred（so，thisdataiscalledfrozenframedata）.Otheradditionalfeaturesmayincludeidleresetand/oridleRPMcontrolthroughthescanner,octaneadjustment,tiresizeinputforvehiclespeedsensor(VSS)calibration,andtheabilitytodisableorenablecertainfeaturesforvarioussystems.Additionally,somescantoolsprovideaninternalsourceofinformation(electronicshopmanual)includingDTCmeanings,modulepinouts,andtermdefinitions.FunctionalProcedure,Chapter7CommonSpecialServiceToolsandEquipments7.1FunctionsofDiagnosticEquipments,AscantoolsimplyplugsintotheDLCafterithasbeenequippedwiththecorrectadaptor.Oncepoweredup,itrequiresvehicleidentificationnumber(VIN)anddatainputfromthetechnician.(SomeOBDIIapplicationswillautomaticallyconfiguretheVINcodeentryoncethescannerisconnectedtotheDLCandtheignitionisturnedon.)Thisautomaticallysetsthescantooltothebaudrateofthemodulesonthedatabus.Thenthetechnicianmustselectthemoduletobediagnosed,aswellasthedesiredmenuitem,suchasmemoryDTCs;keyon,engineoff(KOEO)self-test;keyon,enginerunning(KOER)self-test;functionaltests;anddatastream.,Chapter7CommonSpecialServiceToolsandEquipments7.2OperationofOTCEnhancedMonitorscantool,NewWords,Chapter7CommonSpecialServiceToolsandEquipments7.2OperationofOTCEnhancedMonitorscantool,ScanToolBasicsTakeamomenttofamiliarizeyourselfwiththetoolsbasicfeatures.Thescantoolillustrated（Figure7-26）isarepresentationtoshowfeaturelocations.InformationLightsarelocatedbelowthemaindisplayonthetester,theydisplaycertainswitchandsensoractivityduringtesting.,Chapter7CommonSpecialServiceToolsandEquipments7.2OperationofOTCEnhancedMonitorscantool,Figure7-26Ascantool1.Keypad2.MagneticOverlay3.InformationLights4.DisplayWindow5.SerialInterface6.Stand7.DB25port8.UniversalAdapterCable9.MemoryCartridge10.VehicleAdapterCable(PartNo.6030-03)11.OBDIICable(optional)(PartNo.3305-73)12.25-PinSmartSystemInsert,Chapter7CommonSpecialServiceToolsandEquipments7.2OperationofOTCEnhancedMonitorscantool,TestingSetupIftheOBDCableisrequired,disconnecttheUniversalCable.AttachtheOBDCabledirectlytotheDB25Portandinsertthe25PinSmartSystemInsertintotheOBDIICable（Figure7-27）.ThescantoolwillreceivepowerwhenthevehicleplugisconnectedtotheDiagnosticLinkConnectoronthevehicle.Thesoftwarewillthenreboot.,Figure7-27Insertingthe25PinSmartSystemInsertintotheOBDIICable,Chapter7CommonSpecialServiceToolsandEquipments7.2OperationofOTCEnhancedMonitorscantool,ControllerIdentificationThemenuoptionCONTROLLERIDidentifiesthemodeldetailsoftheEngineControlUnit(ECU).IftheECUisfaulty,thecontrolleridentificationnumberisusedtoobtainanewECUfromyoursupplier.,Chapter7CommonSpecialServiceToolsandEquipments7.2OperationofOTCEnhancedMonitorscantool,ReadCodesThemenuoptionREADCODESshowsalloftheFaultCodessetinthevehiclecomputer.Presstheorkeytoreviewallofthecodes.Pressthekeytoseeafulldescriptionofthefaultcode.,Chapter7CommonSpecialServiceToolsandEquipments7.2OperationofOTCEnhancedMonitorscantool,Thefaultcodesmaybeprinted;pressF2+1orpressF2twice,whichwillbringuptheF2HelpMenu,thenselectPRINT.,Chapter7CommonSpecialServiceToolsandEquipments7.2OperationofOTCEnhancedMonitorscantool,Ifnofaultcodesarefound,thescreenwilldisplay:NOFAULTCODESSET,PRESSANYKEY.PressanykeytoreturntotheSelectTestMenu.ClearCodesThemenuoptionCLEARCODESerasesalloftheFaultCodesfromtheEngineControlUnit(ECU).Makesureyouhavecorrectedthevehiclefaultsbeforeclearingthecodes.,Chapter7CommonSpecialServiceToolsandEquipments7.2OperationofOTCEnhancedMonitorscantool,ActuatorTestsThemenuoptionACTUATORTESTshowsalloftheactuatorsonthevehiclethatareavailablefortesting,Selecttheactuatoryouwanttotest.,Thetestwillbeginrunningimmediatelyforapredeterminedlengthoftime(orpressanykeyandgoontothenexttest),duringwhichthevalve,relayorinjectorwillbetoggledsothatthetechnicianwillbeabletohearifitisfunctioningcorrectly.,Chapter7CommonSpecialServiceToolsandEquipments7.2OperationofOTCEnhancedMonitorscantool,ActuatorTestsvaryfromvehicletovehicle;thetestsavailableare:InjectorTests,EGRControlTest(ExhaustGasRecirculation),FTVControlTest(FuelTankVentilation),FuelPumpRelay,IACTest,ColdStartValve,Sec.AirPump,A/CClutch+FanReadDataThescantoolreadsanddisplaystheelectricalsignalsbeingsentbackandforthtotheECUsothatthetechniciancanseehowtheindividualsensorsandactuatorsarerespondingtoengineconditions.Therearethreemethodsofdisplayingthedatastreaminformation:,Chapter7CommonSpecialServiceToolsandEquipments7.2OperationofOTCEnhancedMonitorscantool,StandardDisplayTheStandardDisplaygroupsdatastreamitemstogetherintopairscalledmodes.Eachmodeisidentifiedbyanumber.Enterthemod