毕业论文摘要随着电控燃油喷射技术的发展和维修认识水平的不断提高，现代轿车中在对装有电控燃油喷射发动机的汽车进行维修时，使用故障诊断仪对发动机电控单元（ECU）进行检测，并根据ECU存储的故障代码进行检修，大多数能判明故障可能发生的原因和部位，会给维修人员的工作带来很大的方便。然而，在对汽车维修时，若仅仅靠故障代码寻找故障，往往会出现判断上的失误。实际上，故障代码仅仅是ECU认可的一个是或否的界定结论，不一定是汽车真正的故障部位，因此，在对汽车进行维修时应综合分析判断，结合汽车故障的现象来寻找故障部位。并且有很多故障是不被ECU所记录的，也就不会有故障代码输出，遇到这种情况时，最为可行的办法就是使用故障诊断仪进行数据流的检测，研究发动机静态或动态数据状况，从而找出故障所在。关键词：电控发动机，电控系统，故障诊断，解决方法I毕业论文AbstractAselectronicfuel-injectedtechnologydevelopmentandmaintenanceknowledgelevelunceasingenhancement,themoderncarsintoequippedwithelectronicfuel-injectedenginecarmaintenance,usingmalfunctiondiagnosismachineofenginecontrolunit(ECU)fortesting,andaccordingtotheECUstoragefailurecodeoverhaul,mostcandeterminepossiblefaultandthereasonofplace,cangivethemaintenancepersonnelworkbringgreatconvenience.However,inthevehiclemaintenance,ifonlybyfaultcodesearchforfault,oftencanappearerrorsinjudgementInfact,failurecodeisonlyECUapprovedayesornodefinedconclusion,isnotnecessarilycartruefailurepositions,therefore,onautomobilemaintenanceshouldbeintegratedanalysis,judgement,combinedwithautofaultphenomenontolookforfailurepositions.AndhavealotofthefaultisnotbeECUrecord,therewon'tbefaultcodeoutput,thishappened,mostfeasiblewayisusingmalfunctiondiagnosismachineindataflowtesting,researchenginestaticordynamicdatastatus,soastofindoutthesourceoftheproblems.Keywords:electricmotors,electriccontrolsystem,faultdiagnosis,solutionII毕业论文目录摘要..........................................................I1.设计总则...............................................11.1前言.....................................................11.2国内外现状..........................................12.发动机电控系统的组成及其工作原理...42.1发动机电控系统的组成及其发展.........42.2发动机电控系统的工作原理................52.3发动机电控系统的功用.......................62.4发动机电控系统的优点.......................63.典型实例的分析与解决方案..................83.1启动困难..............................................83.2怠速太低..............................................93.3怠速过高............................................103.4怠速不稳与喘车.................................103.5消声器放炮........................................113.6发动机动力不足、加速不良故障.......11III毕业论文3.7.氧传感器故障...................................123.8冷却液温度传感器故障......................133.9节气门位置传感器故障......................133.10曲轴位置传感器故障.......................143.11发动机水温过高甚至超过红线.........153.12发动机在运转过程中发出难闻的味道.153.13行驶时跑偏......................................153.14离合器分离不彻底...............................173.15离合器打滑......................................173.16离合器分离或接合时有异响............183.17变速器运转过程中有无异响............183.18驱动桥..............................................193.18.1驱动桥是否过热...........................193.18.2汽车行驶时驱动桥是否发异响.....194典型症状现象及分析.............................204.1运行异常............................
