杨四军武科大教授单元十 汽车检测与维修(课件)-《汽车专用英语 第三版》同步教学 （人交版）

汽车商标汽车及其历史汽车发动机汽车底盘单元一单元二单元三单元四汽车电气设备汽车车身汽车使用说明书及维修手册汽车检测与维修设备单元五单元六单元七单元八汽车维护汽车检测与维修新能源汽车概述汽车商务接待单元九单元十单元十一单元十二

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活塞连杆组故障诊断与修复汽车检测与维修

学习目标

完成本学习任务后，你应该能：1.了解汽车诊断与维修的基本流程；2.掌握汽车诊断与维修术语的英语表达；3.对相关内容进行阅读和翻译；4.填写故障分析检查表；5.正确完成课后练习。建议学时4

学时Text

Despitethebestmaintenance,problemsmayoccurwithyourcar,thenyourcarneedsservice.Ifyouseea“checkengine”ora“serviceenginesoon”lightinyourcombinationmeter,yourcarhasstoredadiagnostictroublecode,whichmeansthecomputersystemonyourvehiclehasdetectedaproblemwithinvarioussystemsitcontrols.Howtoproceedwithtroubleshooting?Automobile'sdiagnosticsandrepairprocedures(Fig.10-1)areasfollowing.AutomotiveDiagnosisandMaintenanceFig.10-1AutomobilesDiagnosticsandRepairProceduresText

CustomerProblemAnalysisCheckTakethecombinationmeterforexampletoshowthecustomerproblemanalysischecksheet(Tab.10-1)asfollowing.AutomotiveDiagnosisandMaintenanceText

ProblemSymptomConfirmationandCircuitInspectionAcarhasmanydifferentsensorsthatmonitorthevariousvehiclesystems.Ifthetroublecodelighthasbeenilluminated,itshowsthevehicleentersinto“limpmode”.Take“enginetrouble”asanexample,whenyouseea“malfunctionindicatorlight”(Fig.10-2)ora“serviceenginesoon”lightinyourcombinationmeter,Itmeansyourcarhasstoredadiagnostictroublecode.AutomotiveDiagnosisandMaintenanceFig.10-2MalfunctionIndicatorlightText

ProblemSymptomConfirmationandCircuitInspectionLocateyourvehicle'sdiagnosticconnector(Fig.10-3),mostlyitisinthedriverseatattheside.Ifnot,pleasecheckyourowner'smanual.AutomotiveDiagnosisandMaintenanceFig.10-3DiagnosticConnectorText

ProblemSymptomConfirmationandCircuitInspectionConnectcodereadertotheconnector.Thecodereaderwillautomaticallyturnonandpromptyouthenextoperationonreadingfaultcode(Fig.10-4).Oncethetroublecodehasbeenidentified,itsidentificationwillbedisplayedonthecodereader.AutomotiveDiagnosisandMaintenanceFig.10-4ReadingFaultCodeText

ProblemSymptomConfirmationandCircuitInspectionUponcompletingtherepairwork,it'snecessarytoclearthetroublecodeandrechecksystem.Aftercodeshavebeenclearedthecomputersystemisreadyforinternaltesting,thismeansthatwhilethecarisinoperationthecomputerisperformingtests.Thesetestsarecalled“monitors”,mostcarshavebetween4and8monitorsystems.AutomotiveDiagnosisandMaintenanceText

RepairorReplaceWhenthetroublesarefound,carneed“RepairorReplace”.Thismeanstorepairorchangethedefectiveparts.Nowtake“changesparkplugs”forinstance,explainingthe“RepairorReplace”operation.Parkthecaronaflatdrysurface,engineoff,pulluptheemergencybrakeset.Gatherthepropertools:Socketwrench,sparkplugsocket,gappingtool,safetyeyewear,glovesandtowelsetc.AutomotiveDiagnosisandMaintenanceText

RepairorReplaceFirst,identifytheignitionsystemyourcarhas,mostcarshaveaDIS(directignitionsystem).Gentlybutfirmlytwisttheboottoloosentheseal,nowremovethesparkplugwire(Fig.10-5).Thengentlypullthesparkplugwirefromthesparkplug.Removetheplugwirefromthecoilterminal.AutomotiveDiagnosisandMaintenanceFig.10-5RemovingtheSparkPlugWireText

RepairorReplaceRemoveallplugwiresfromthepackaging,straightenthemoutandorganizetheplugwiresfromthelongesttotheshortest.Paysattention,plugwiresindifferentcylinderwillbedissimilarwiththeaimoflatermatchingandreplacingplugwires(Fig.10-6)atatime.AutomotiveDiagnosisandMaintenanceFig.10-6MatchingandReplacingPlugWiresText

RepairorReplaceNext,removedebrisfromthesparkplughole,thenuseasocketwrenchandsparkplugsockettoloosenandremovesparkplug(Fig.10-7)bycounterclockwise.Inspectsparkplug'sworkanddamagestate.AutomotiveDiagnosisandMaintenanceFig.10-7RemovingSparkPlugText

RepairorReplaceBeforereinstallingnewsparkplugs,trytomakesurewhetheryouareinstallingismatchedforyourcarandenginesizeornot.Measuringthesparkpluggap(Fig.10-8)betweentheelectrodeswithafeelergauge,mostsparkpluggapsarebetween0.035～0.045inch.Anincorrectsparkpluggapwillresultinlowpower,poormileageandpossiblyacheckenginelightnotice.AutomotiveDiagnosisandMaintenanceFig.10-8MeasuringtheSparkPlugGapText

RepairorReplaceSavetheoldsparkpluginthenewsparkplugboxes,storethemforfuturereference.Onceyouhavecompletedthesparkplugchange,remembertostarttheengineandinspecttherunningcondition,itshouldbesmoothwithnoextranoises.Ifyourengineisrunningrough,trytocheckthesparkplugwirestomakesurenoneofthempoppedofforloosened.AutomotiveDiagnosisandMaintenance参考译文

尽管车辆维护的很好，故障仍然不可避免的会出现。出现故障时，车辆就需要维修作业。如果你看到仪表盘上的故障指示灯或发动机维护灯亮着，这就表明你的车存储了一个故障码，也就意味着汽车电脑在车辆的各种系统中检测到了某个故障。如何检修车辆故障呢？汽车诊断与维修的基本流程如图10-1所示。汽车诊断与维修图10-1诊断维修基本流程图参考译文

客户描述故障分析下面以组合仪表为例说明客户描述故障分析表（表10-1）。汽车诊断与维修参考译文

故障症状确认和系统检查汽车上装配有许多不同的传感器用以监测车辆各个系统的工作状况。如果故障指示灯亮了，就意味着车辆进入“保护模式”。以发动机故障为例，当你看到仪表盘上的故障指示灯点亮(图10-2)或发动机维护灯亮着，这就表明你的车存储了一个故障码。汽车诊断与维修图10-2故障指示灯点亮参考译文

故障症状确认和系统检查找到车辆的故障诊断接口（图10-3），大多数是在驾驶员座位一侧，如果不在，请查阅用户手册。汽车诊断与维修图10-3故障诊断接口参考译文

故障症状确认和系统检查将解码器接上诊断接口，解码器会自动启动并提示你进行故障码读取（图10-4）的下一步操作。一旦故障码被确定，解码器就会将确定的故障码显示出来。汽车诊断与维修图10-4读取故障码参考译文

故障症状确认和系统检查每次维修作业完成后，必须清除故障码并再次确认系统。一旦故障码被清除，车辆电脑就进入自我测试状态，这也就意味着当车辆起动时计算机自动执行内部系统测试。这种测试也被称作“监测”，大多数车辆有4～8个监测系统。

维修与更换故障部位被确定后，接下来就是维修或更换车辆故障零件或系统。下面以“更换火花塞”为例讲解“维修和更换”作业。将车辆停在水平干燥的地面上，关闭发动机，拉起驻车制动器。准备工具：套筒扳手、火花塞套筒、厚薄规、安全眼镜、手套和毛巾等。汽车诊断与维修参考译文

维修与更换首先，确认车辆点火系统的类型，大多数汽车的点火系统为DIS（直接点火）型。轻轻晃动火花塞胶套使其松旷。拆卸高压线（图10-5）与火花塞及分电器的连接。汽车诊断与维修图10-5拆卸高压线参考译文

维修与更换从维修包中取出所有新的高压线，按最长到最短的顺序弄直和整理高压线。注意：不同汽缸的高压线长度不一样，这便于稍后匹配更换高压线（图10-6）。汽车诊断与维修图10-6匹配更换高压线参考译文

维修与更换接下来，用压缩空气清除火花塞孔，然后用套筒扳手和火花塞套筒按逆时针方向预松并拆卸火花塞（图10-7）。检查火花塞的工作和损坏情况。汽车诊断与维修图10-7拆卸火花塞参考译文

维修与更换在安装新的火花塞之前，确定准备安装的火花塞是否与发动机尺寸相匹配。并用厚薄规（又称塞尺）测量火花塞电极间隙（图10-8），大多数车辆的火花塞间隙为0.035～0.045英寸。采用劣质火花塞将会导致发动机功率下降、油耗上升，甚至会导致发动机故障指示灯点亮。将换下的火花塞保存在新的火花塞盒内，以备以后作参考之用。更换火花塞后记得检查发动机工作情况：发动机应运转流畅、无异响。如果发动机工作不稳定，则检查各缸高压线有无脱落或松动现象。汽车诊断与维修图10-8火花塞间隙测量ReadingMaterial

EngineoverheatingTherearemanyconditionsoftheautomobilethatresultinoverheating,andthedegreeofoverheatingisindicatedbythetemperaturegaugeontheinstrumentpanel.Someconditionswillcauseonlyaslightchangeintherecordedtemperature,otherswillresultinarapidriseintemperatureandviolentboilingofthecoolant.Stillsomemaycauseonlyaslightincreaseinrecordedtemperature,butwillbemorenoticeableinengineperformance.EngineTroubleshootingReadingMaterial

EngineoverheatingWhentroubleshootingthecauseforoverheatingandconsequentlossofcoolant,thefirststepistomakecarefulvisualinspectiontoseeifthereisanyevidenceofexternallinkage.Allsurfacesoftheradiatoranditshoseconnectionsshouldbecarefullyinspected.Leaksgenerallycausecorrosion,whichiseasilyseen,Thevisualinspectionalsomustincludethecoolingfananditsdrivebelt.Itisnottoounusualforcrackstoformintheenginewaterjacket.Whencracksoccur,theconditionisusuallyindicatedbyextremeoverheating.Thecrackisoftendifficulttolocate,becauseitisnotalwaysvisibletothenakedeye.Theconditionisalsocomplicatedbythefactthatthecrackusuallywillclosewhentheengineiscold,andopenonlywhentheengineisatoperatingtemperature.EngineTroubleshootingReadingMaterial

CleaningtheCoolingSystemUnlessveryseverelycloggedwithrustandhardscale,coolingsystemscanbecleanedwithspecialchemicalsdesignedforthepurpose.Theprocedureistofillthesystemwithwater,thenputinthechemical.Thechemical,afterdissolvingtherustandscale,isflushedfromthesystem.Inseverecasesofcloggedradiators,itisnecessarytoremovethemandhavethemcleanedbyspecializedequipment.EngineTroubleshootingReadingMaterial

HighonConsumptionQuiteoftenhighoilconsumptionisblamedonthepistonrings.Whilewornpistonringsandcylinderwallsdocauseincreasedoilconsumption,thereareagreatnumberofotherthingsthatcouldbeatfault,eithersinglyorincombination.Wornvalveguidesarealsoafrequentcauseofhighoilconsumption.Whenoilisbeingconsumedbypassingthroughtheengine,itusuallywillcauseheavybluesmoketocomefromtheexhaust,particularlyaftertheenginehasidledforseveralminutes.EngineTroubleshootingReadingMaterial

LowoilPressureInmostcasesoflowoilpressure,thepressureissatisfactorywhentheengineisfirststartedup,thenitdropsastheenginewarmsup.Thisconditionisalmostpositiveproofthatexcessiveclearanceexistsatsomepoint,orpoints,suchasconnectingrodbearings,mainbearings,camshaftbearings,etc.Whencold,theoilhasthickenedanddoesnotflowasreadilythroughtheclearance.Whentheoilheatsupandthinsout,itflowsthroughthewornbearingsofastthatthepumpcannotmaintainsufficientpressure.EngineTroubleshootingReadingMaterial

AbnormalEngineNoisesandTheirCausesThefollowinglistingwillpointoutthemostcommoncausesofsounditselfandwhatmustbedonetoeliminatethem.1.Pistonslapisaverycommonnoisemostnoticeablewhenanengineiscold.Apistonthatslapsagainstthecylinderwallproducesahollow,muffled,bell-likesound,quiteaudiblewhenanengineisoperatingunderloadatlowrpm.Pistonslapresultsfromwornpistonsorcylinders,collapsedpistonskirts,excessivepiston-to-cylinderwallclearance,misalignedconnectingrods,oralackoflubricatingoil.Therefore,inordertocorrectpistonslap,itwillbenecessarytoreplacedorresizethepistons,reborethecylinderorreplacethesleeves,replaceorrealigntherods,oraddoiltotheengine.EngineTroubleshootingReadingMaterial

AbnormalEngineNoisesandTheirCauses2.Anabnormalsoundoriginatingfromsomeformofpiston-ringproblemisaudibleduringengineacceleration.Tocorrectthecauseofringnoise,itmaybenecessary,therefore,toreplacetherings,thepistons,orthesleevesorreborethecylinders.3.Asoundnotfrequentlyheardinanengineisthatofapistonringstrikingtheringridgeatthetopofthecylinder.Thisparticularproblemcausesaverydistinctandhigh-pitched,metallicrappingorclickingnoiseaudibleatallenginespeedsbutparticularlyondeceleration.Torepairthecauseofthissound,itwillbenecessarytoreplacethepistonpinorconnectingrodbearings.EngineTroubleshooting参考译文