Breakdown phenomenon
The Feng Tian of an embarking 1ZR engine blocks Luo La car, appeared to make a person the breakdown of unimaginably queer: It is more difficult that engine is started, can start sometimes, but most moment cannot be started, and without any rules but abide. Appearance observes when the engine that start, engine revolution counter is met the point of view with proper deflexion, breakdown indicator light is bright, indicator light of the breakdown after starting goes out normally, diagnose appearance examination with breakdown, without malfunction code. If cannot be started normally, receive through inserting those who dial ECM to go up repeatedly, can start engine sometimes, the sense that gives a person should be a contact undesirable cause.
Additional, if open accumulator negative pole ceaselessly, the following day accumulator voltage can drop 5V is the following, explain this car leakage of electricity is more serious.
Breakdown is diagnosed with eliminate
Join computer diagnoses appearance, without malfunction code, it is normal that data shedding shows. The examination supplies oily system and air feed system, did not discover unusual, but job of engine ignition system is unusual, sparkplug does not have flash over. Check discovery, 81 of the B31 on ECU sutural not quite as close together as the join between socket, demolish 81 sutural electrical outlet, clamp of the mouth that use a needle gently the reload after clamp is answered, can start engine sometimes, but not be to start metropolis success every time.
This car uses a car as education all the year round, on the wiring harness inside engine cabin insert receive insert unplug more frequent. Preliminary suspicion ECM is inserted with what wiring harness is linked together receive a contact undesirable, then, changed to start the wiring harness of engine room, start function to be started normally, but did not spend time a few days, breakdown happens again, and breakdown phenomenon and same before, ignition system still cannot work normally. Insert those who unplug ECM and wiring harness are linked together repeatedly receive, can start engine now and then, but the probability that starts successfully is lower and lower. We suspect engine ECU job is bad, changing new engine ECU is finished after matching, engine starts a success. But the following day again when test-drive, when starting, engine does not have any reaction again, the indicator light on appearance dial, emergency warning lamp is not bright also, measure accumulator voltage to have 4.5V only with avometer, explain breakdown of leakage of electricity still exists.
Graph 1 abundant cropland blocks Luo La engine to control systematic circuit to pursue
After undertaking complementing charging to accumulator, engine can be started normally again. But phenomenon of the breakdown after a few days returns, engine is started still special difficulty, explain breakdown was not eliminated thoroughly.
We must comb diagnostic train of thought afresh.
1. engine can be started sometimes, showing ignition system to control the part beyond module except engine should be normal, because of this model the igniter that every cylinder of engine has an independence each, 4 sparkplug misfire, the possibility small Hu Jiwei that damages at the same time. IGT signal is apart, if the problem can bring about a crock not to work, can cause 4 crocks misfire at the same time, may be IGF signal only unusual.
2. leakage of electricity is serious, demonstrative circuit has short circuit (have load) or the fault receives a phenomenon to exist. The possibility of short circuit is lesser, and the possibility that the fault receives is larger.
Then, we decide each to check engine to control module sutural whether does the voltage that go up accord with a standard (have a few sutural need to detect with oscillograph undee) , disconnect accumulator negative pole, dial next A50 and B31, receive again on accumulator negative pole. Detect when A50, the foot is brought to detect to voltage of abnormal 12V power source in 2. Consult after relevant data, we are going against circuit to be checked forth, discover front of this black line passes engine room relay the 1A of box unit B is inserted receive 1 brings a foot to be linked together with accumulator directly, black line back end is connecting engine ECU, heat model the wiring such as oxygen sensor and quality air flowmeter, make these equipment are in working status all the time. And the 1B that checking unit B is inserted receive when, discovery cites a base 4 numbers little however the lead of a black (graph 1 in place of red dotted line shows) , so far breakdown reason is found out basically.
Answer black lead outfit 1B to insert receive 4 cite a base, those who install good engine ECU insert receive, the negative pole of join good accumulator, open ignition switch, observation appearance everything is normal, engine is started smoothly.
Whether be eliminated thoroughly for breakdown of test and verify, start engine again the following day, still can start normally, pass a week dog and observe, everything is normal, breakdown is eliminated thoroughly.
The 1B on unit B is inserted receive 4 bring a foot to receive voltage of 12V power source, 1A is inserted receive 1 cites a base also is voltage of 12V power source, from apparently see voltage do not have a difference, but it why can you cause engine to start is difficult to why can you cause engine to start? Because there is sequential circuit to exist in engine ECU,this is, power source voltage appears prematurely in engine ECU + B, + of B2 bring a foot to go up, the sequential circuit logic that can make engine ECU medium appears mistake, cause engine ECU thereby the job is abnormal.
Because,leakage of electricity is engine ECU, heat model the wiring such as oxygen sensor and quality air flowmeter is linked together with accumulator directly, make these equipment are in working status all the time, cause accumulator to cannot store electric energy.
Maintain brief summary
1. this car uses a car for education, for the student the exercitation is used, because education ends,breakdown existence is hind, directive teacher did not recover from an illness trouble spot in time, this kind of circumstance needs our learn a lesson.
Be in as the teacher after course ends, answer to recover from an illness trouble spot in time everyday, and when be in charge of the leader that education works to end in semester, answer education to undertake checking with the car, ensure these car do not have breakdown, assure the success that education works.
2. although the breakdown of this car already eliminated, but many roundabout way took in the process that eliminate, the reason is insufficient to the analysis of breakdown science, existing blind self-confidence, think this car breakdown is a contact undesirable cause, extended the time of trouble removal thereby. Many somes of scientific analysis wants when will encountering this kind of problem again henceforth, a few less blind self-confidence.
