发动机电控系统故障诊断仪的设计与实现-毕业论文.doc

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， 关键词：电控发动机，电控系统，故障诊断，解决方法 Abstract As electronic fuel-injected technology development and maintenance knowledge level unceasing enhancement, the modern cars in to equipped with electronic fuel-injected engine car maintenance, using malfunction diagnosis machine of engine control unit (ECU) for testing, and according to the ECU storage failure code overhaul, most can determine possible fault and the reason of place, can give the maintenance personnel work bring great convenience. However, in the vehicle maintenance, if only by fault code search for fault, often can appear errors in judgement In fact, failure code is only ECU approved a yes or no defined conclusion, is not necessarily car true failure positions, therefore, on automobile maintenance should be integrated analysis, judgement, combined with auto fault phenomenon to look for failure positions. And have a lot of the fault is not be ECU record, there wont be fault code output, this happened, most feasible way is using malfunction diagnosis machine in data flow testing, research engine static or dynamic data status, so as to find out the source of the problems. Keywords: electric motors, electric control system, fault diagnosis, solution 目录 摘要 I 1.设计总则 1 1.1前言 1 1.2国内外现状 1 2.发动机电控系统的组成及其工作原理 4 2.1发动机电控系统的组成及其发展 4 2.2发动机电控系统的工作原理 5 2.3发动机电控系统的功用 6 2.4发动机电控系统的优点 6 3.典型实例的分析与解决方案 8 3.1启动困难 8 3.2怠速太低 9 3.3怠速过高 10 3.4怠速不稳与喘车 10 3.5消声器放炮 11 3.6发动机动力不足、加速不良故障 11 3.7.氧传感器故障 12 3.8冷却液温度传感器故障 13 3.9节气门位置传感器故障 13 3.10曲轴位置传感器故障 14 3.11发动机水温过高甚至超过红线 15 3.12发动机在运转过程中发出难闻的味道 15 3.13行驶时跑偏 15 3.14离合器分离不彻底 17 3.15离合器打滑 17 3.16离合器分离或接合时有异响 18 3.17变速器运转过程中有无异响 18 3.18驱动桥 19 3.18.1驱动桥是否过热 19 3.18.2 汽车行驶时驱动桥是否发异响 19 4典型症状现象及分析 20 4.1运行异常 20 4.2气味异常 20 4.3外观异常 20 4.4温度异常 21 4.5排烟颜色异常 21 4.6耗油异常 21 4.7异常声响 22 4.8仪表异常 22 4.9性能异常 22 4.10间隙异常 22 5 总结与展望 23 5.1总结 23 5.2 存在不足 23 5.3