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The Cherokee generator causes the sudden flameout breakdown
http://www.enpinfo.com/Engine/Tech/Project/200903/25113.html
切诺基发电机引起突然熄火的故障
Breakdown phenomenon:
A six cylinder electrically controlled fuel injection Cherokee jeep, in travel sudden flameout. Opens approaches accumulator cell's central distributing box, the fuse F2(20A) fuse. After the replacement, the connection ignition lock, this fuse blows a fuse.
Principle of work:
According to the above breakdown phenomenon, first reads the breakdown code.
In 5s, rotates the ignition lock repeatedly, this time on display board's trouble lamp demonstrates two codes:
One is 41, its meaning is the alternator field circuit bad;
Another is 42, the meaning is the automatic turnoff relay (the ASD relay) control circuit bad, or in ECU does not have ASD (automatic turnoff) the black-white control signal.
The ASD relay installs in approaches in accumulator cell's central distributing box.
When the ignition lock is in puts through the position and the engine revolve, the ECU control puts through the ASD relay earth circuit, puts through the ASD relay winding electric circuit, causes the relay normally opened contact closed, puts through the accumulator cell to the ignition coil, the spray hole as well as the generator field winding's feed circuit.
Meanwhile, also puts through the fuel pump relay winding electric circuit, causes the fuel pump relay electronic contact closed, puts through the fuel pump power source to cause the fuel pump work.
When ECU has not received the crank corner signal when 3s, then controls the ASD relay to cause its electronic contact separation, thus causes the blow system, the ignition system and the charge system's power source is shut off, simultaneously also causes the fuel pump to stop the work.
Therefore the ASD relay is the electrically controlled unit main protective device.
Trouble shooting:
Because according to this control principle, the above breakdown is very possible is the ASD black-white control signal circuit or the ignition coil, the spray hole, the generator field electric circuit presents the short trouble result, in these 4 electric circuit's any electric circuit short-circuits, will cause F2 to blow a fuse, creates the ignition coil and the spray hole power failure stop work, will thus cause the stalling of engine.
Carries on the inspection to the above each line, had not discovered that exterior has the ground connection, the short pass.
But when in touching the generator, feels the scald one's hand. Dismantles the generator, surveys field winding's static resistance with the ohmmeter, its resistance number is 0 (rating for 2.2Ω-3.0Ω).
Therefore, concluded that has the short trouble for the generator field electric circuit.
Installs the good fuse, replaces the generator, eliminates the breakdown code, the starting engine test run, and no longer blows a fuse, the trouble lamp is not bright, breakdown thorough elimination.
故障现象：一辆六缸电控燃油喷射切诺基吉普车,行驶中突然熄火。打开靠近蓄电池的中央配电盒,熔丝F2(20A)熔断。更换后,接通点火开关,该熔丝又熔断。
工作原理：根据上述故障现象,首先读取故障代码。在5s内,反复转动点火开关,此时仪表板上的故障指示灯显示出?姶个代码:一个为41,其含义是交流发电机磁场电路不良；?玩一个为42,含义是自动切断继电器(ASD继电器)的控制电路不良,或ECU内无ASD（自动切断）继电器控制信号。
ASD继电器安装在靠近蓄电池的中央配电盒内。
当点火开关处于接通位置且发动机?畚转时,ECU控制接通ASD继电器接地电路,接通ASD继电器线圈电路,使继电器常开触点闭合,接通蓄电池向点火线圈、喷油器以及发电机磁场绕组的供电电路。与此同时,也接通燃油泵继电器线圈电路,使燃油泵继电器触点闭合,接通燃油泵电源而使燃油泵工作。
当ECU在3s之内没有收到曲轴转角信号时,便控制ASD继电器使其触点断开,从而使喷油系统、点火系统和充电系统的电源被切断,同时也使燃油泵停止工作。因此ASD继电器是电控单元的主要保护器件。
故障排除：根据这一控制原理,上述故障很可能是因ASD继电器控制信号电路或点火线圈、喷油器、发电机磁场电路出现短路故障所致,这4条电路中的任何一条电路短路,都会使F2熔断,造成点火线圈和喷油器断电停止工作,从而导致发动机熄火。
对上述各条线路进行检查,未发现外部有搭铁、短路现象。但当于触摸到发电机时,感到烫手。拆下发电机,用电阻表测量磁场绕组的静态电阻,其阻值为0(规定值为2.2Ω-3.0Ω)。因此,断定为发电机磁场电路有短路故障。
重新安装好熔丝,更换发电机,清除故障代码,起动发动机试?畚转,且不再熔断,故障指示灯不亮,故障彻底排除。
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初めまして！
遊びに来ました！
これからヨロシクお願いしま～す<m(__)m>
2009/6/17(水) 午後 2:58[ 寿子ちゃん ]