摘要排放控制系统是由废气再循环系统、燃油蒸汽回收装置、二次空气喷射装置和三元催化转换器等组成。它的故障一般不易被电脑故障自诊断系统发现,因此故障的诊断只能通过对有关零部件的检测来查找,所以电喷车排放控制系统的定期检修就显得尤为重要。该系统由电脑根据冷却液的温度、转速、节气门开度等运转参数,通过燃油蒸发控制电磁阀来控制该系统的工作。若正常行车中车厢内有燃油气味(若该装置工作不良,夏季尤甚)或发动机怠速不稳,而电脑自诊断系统显示正常时,应按下述步骤检查。启动发动机至正常工作温度,并使之怠速运转。拔下蒸气回收罐上的真空软管,用手检查有无真空吸力。当系统工作正常时,在发动机怠速运转中,电磁阀应不通,无真空吸力。若此时有吸力,应检查电磁阀线束插头内的电源电压。有电压,为电脑故障;无电压,为电磁阀故障。关键词：尾气排放，汽车污染物，控制系统，发动机IAbstractTheemissioncontrolsystemiscomposedoftheexhaustgasrecirculationsystem,thefuelsteamrecoveryunit,thetwoairejectorandthethreeelementcatalyticconverter.Itsfailureisgenerallynoteasytobefoundbycomputerfaultselfdiagnosissystem.Therefore,faultdiagnosiscanonlybefoundbydetectingpartsandcomponents,sotheperiodicmaintenanceofEFIvehicleemissioncontrolsystemisparticularlyimportant.Thesystemiscontrolledbythetemperatureofthecoolant,thespeedandtheopeningofthethrottle,andcontroltheworkofthesystembythecontroloftheelectromagneticvalvebytheevaporationofthefuel.Ifthecarnormaldrivinginthefuel(ifthedeviceisbadsmell,especiallyinsummer)orengineidlinginstability,andcomputerselfdiagnosissystemshowednormal,shouldbecheckedaccordingtothefollowingsteps.Starttheenginetonormalworkingtemperatureandmakeitidle.Pulloutthevacuumhoseonthesteamrecoverytankandcheckthevacuumsuctionwithyourhand.Whenthesystemisworkingnormally,thesolenoidvalveshouldnotbeusedandthereisnovacuumsuctionintheengineidlespeed.Ifthereisasuctionatthistime,thevoltageofthepowersupplyintheplugofthesolenoidharnessshouldbechecked.Thereisavoltage,acomputerfault,novoltage,asolenoidvalvefailure.II目录1摘要............................................................................................................................................2奥迪A6排放系统故障诊断流程..........................................................................................12.1接车.............................................................................................................................13.1故障检修流程.............................................