To electronic-controlled the trouble that starts Electromechanical to control a system is diagnosed, answer to undertake by undermentioned program:
1, inquiry user, the time that breakdown produces, phenomenon, circumstance at that time, the reason when malfunctioning and whether to pass the overhaul, disassemble etc.
2, preliminary and affirmatory a breakdown limits and place.
3, v malfunction code, and the content of failure isolation.
4, the breakdown range that shows by malfunction code, undertake the overhaul, notice whether contact becomes loose especially, fall off, lead connection is correct.
5, the overhaul ends, whether did breakdown of come true card already eliminate truly.
6, do not give malfunction code like tone, perhaps do not check after v give breakdown content, criterion according to breakdown phenomenon, judge a breakdown limits roughly, the method that uses one by one to check component character of service tries to eliminate.
2, the diagnosis of common breakdown
1, engine cannot be started or start difficulty
(1) starter does not turn or rotational and slow
1) examination accumulator voltage.
2) check connection of accumulator terminal, lead to wait to whether become loose.
3) the examination starts a department, include to ignite the switch, switch that start, empty shelves starts switch and starter case, whether does departmental circuitry join become loose.
(2) starter is rotational and normal, but engine cannot be started
1) v malfunction code.
2) circumstance of job of examination fuel pump.
3) examination idle it is normal whether fast system works (be like idle fast system work is abnormal, the engine when stepping to quicken footplate can be started) .
4) examine ignition system, include high-pressured scintilla, light a fire when circumstance, sparkplug.
5) the examination has into air system without flat place.
6) whether do examination air flowmeter or air pressure sensor work undesirable.
7) it is normal whether the examination fuel injector, microtherm fuel injector that start works.
8) circuit of examination EFI system, include ECU connector to concern terminal.
9) examination machinery has without reason block partly.
2, engine idle fast undesirable
1) v malfunction code, analyse breakdown reason.
2) the examination has into air system without flat circumstance.
3) the working circumstance of the PCV a powerful person that examines crankcase ventiduct (idle fast when, PCV a powerful person should be shut) .
4) the idle on door of examination solar term fast whether to adjust bolt correct, if adjust bolt incorrect, can bring about idle fast when mixture gas is too rare, bring about engine idle fast flabby.
5) the examination ignites when circumstance.
6) circumstance of eject of examination fuel injector.
7) circuit of examination EFI system and component job circumstance.
8) the state that examines mechanical system.
3, idle fast exorbitant
1) door of examination solar term whether hairpin and cannot shut.
2) whether is fuel injector of examination cold start-up continueing fuel injection.
3) whether does sensor of position of door of examination solar term output voltage incorrect.
4) examination fuel spraying pressure is exorbitant.
5) whether tube of sensor of examination booster vacuum falls off or rupture.
1) check idle it is normal whether fast control system and VSV a powerful person work.
2) fuel injection circumstance reachs examination fuel injector to whether drip leakage.
3) v malfunction code, judge breakdown reason.
4) reach component job situation to EFI system circuit.
10) the examination ignites when incorrect.
4, engine rotate speed is flabby
1) v malfunction code, analyse breakdown reason.
2) the examination has into air system without flat circumstance.
3) examination fuel pump offers oily condition, the pressure of fuel pipeline is normal.
4) whether does adjuster of examination fuel pressure work abnormal.
5) circumstance of eject of examination fuel injector, whether individual fuel injector does not work or fuel injection quantity forbids truly.
6) examine ignition system, if ignite when carbon deposit of circumstance, high-pressured scintilla circumstance, sparkplug.
7) examination air filter whether does filter core jam.
8) examination benzine filter whether does filter core jam.
9) reach component job situation to EFI system circuit.
10) check mechanical part, wait like clearance of cylinder pressure, valve.
5, engine temper
Engine temper phenomenon passes as a result of mixture gas mostly rare or ignition time is too late be caused by.
1) v malfunction code, analyse breakdown reason.
2) examination air inlet duct has without flat circumstance.
3) signal of output of sensor of position of door of examination solar term is correct.
4) the examination ignites when circumstance.
5) whether does examination fuel pressure pass low.
6) whether does time of fuel injection of examination fuel injector pass short.
7) examination fuel injector whether hairpin jams.
8) circuit of examination EFI system and component job circumstance, basically each concern sensor, pressure sensor of the sensor that be like oxygen, water lukewarm sensor, inlet temperature sensor, air inlet duct.
6, vent-pipe blowouts
Vent-pipe blowouts the phenomenon basically passes to thick, individual crock does not work and burn as a result of mixture gas time is incorrect wait for combustion not complete element is caused.
1) v malfunction code, analyse breakdown reason.
2) the examination ignites when, whether to ignite time spends evening.
3) fuel injector of examination cold start-up whether still fuel injection perhaps produces a leakage, find out a reason further.
4) the microtherm fuel injector that start is time switch invalidation.
5) misfire of individual crock sparkplug or scintilla are too weak.
6) check fuel injector, whether to put in fuel injection excessive, fuel injection of individual perhaps crock crosses much phenomenon, whether to have a leakage.
7) examination fuel pressure is exorbitant, pressure adjuster whether invalidation brings about the pipeline that answer oil to cannot open an oil, whether tube of sensor of pressure adjuster vacuum falls off or rupture.
8) sensor of examination air flowmeter and signal of output of sensor of position of solar term door are correct.
9) examination EFI circuit and the working circumstance of concerned sensor.
7, engine is quickened undesirable
1) examination air inlet duct is flat.
2) whether does examination ignition time spend evening.
3) v malfunction code, analyse breakdown reason.
1) system of examination fuel spray, if light circumstance of job of oil pressure force, fuel injector.
2) examine ignition system, explode especially the job of shake sensor and igniter is regular.
3) sensor of position of door of examination solar term is normal.
4) the working case that examines EFI circuit and the cell that concern with fuel eject.
5) circumstance of job of clearance of examination cylinder pressure, valve, sparkplug and match gas phase wait for a project.
3, typical component breakdown and its reason
1, ECU
Generally speaking, ECU is more reliable, appear not easily breakdown, below normal use circumstance, the fault rate of 100 thousand kilometre not prep above one thousandth, but grow too when engine working hours (travel course of development exceeds 150 thousand kilometre) when, the fault rate of ECU increases apparently, the reason of breakdown basically is:
1) solder dot loosens;
2) capacitance component invalidation;
3) collect is agglomerate attaint;
4) electronic-controlled and unit fixed foot bolt becomes loose;
5) electronic component attaint.
Once ECU appears breakdown, can cause engine to cannot be started or start hard, wait for a phenomenon greatly without capacity of oil of high speed, bad news.
2, sensor
The car is divided commonly with sensor mix for thermal resistor type, vacuum pressure type, mechanical driven type press electric type to wait for a few kinds, relative to character, sensor is in electronic-controlled in benzine spray system easy occurrence breakdown, breakdown reason basically is:
1) stretch invalidation of yuan of parts of an apparatus;
2) vacuum diaphragm damaged;
3) osculatory place wears away or ablation;
4) periphery circuitry breakdown.
Sensor is in charge of offerring engine operating mode to ECU, accordingly, when general occurrence breakdown, immediate impact ECU convinces the source of breath definitely, the control to engine also out of control or control abnormal.
3, receive insert join
Electronic-controlled spray system has benzine to be received numerously insert join, because its job is in the environment of a vibration, much dirt, high temperature, Yi Chao, time grows, produce breakdown easily. The environment causes the main reason of breakdown badly:
1) accept be no longer in force of plug-in unit ageing;
2) contact becomes loose;
3) contact contact is undesirable.
Receive insert join when occurrence breakdown, engine work is not steady, stand or fall, law of imitating test of omen of general and usable breakdown will diagnose.
4, fuel injector and cold start-up fuel injector
Fuel injector and cold start-up fuel injector are fragile one of, especially because domestic benzine is oleaginous and opposite poorer, appear more easily to jam and get stuck dead to wait for a phenomenon. Below normal circumstance, fuel injector should be cleaned one year at least. Main show is in the breakdown of fuel injector:
1) electromagnetism coil job is bad;
2) atomizer gets stuck dead;
3) jam;
4) drop leakage;
5) pulverization situation is bad;
6) periphery circuit.
Fuel injector breakdown basically can cause engine to some crock does not work or work undesirable. Additional, quantity of fuel injection of each crocks of fuel injector differs too big (15 seconds exceed 8~10ml) , also can cause whole engine the job is flabby wait for breakdown.
1, conduit of vacuum hose etc
Electronic-controlled benzine spray system has conduit of many vacuum tube etc, because its are rubber products mostly, be heated, touch oil and time to grow, can produce ageing. Main show is in its breakdown:
1) glue is in charge of ageing;
2) nozzle burst;
3) checkpost did not get stuck close;
4) interface becomes loose.
Its are behaved finally for flat, make mixture gas crosses rare, engine to start difficulty or idle fast undesirable, wait feebly quickly.
2, fuel pressure adjuster
Fuel pressure adjuster is used at adjusting injection pressure, the meeting when occurrence breakdown affects the fuel delivery of engine apparently, make engine offers oil the flabby, difficulty that start, wait feebly quickly. The passageway jams and the diaphragm inside pressure adjuster damages, can cause trouble of fuel pressure adjuster.
3, filter
Of air filter, benzine filter and engine oil filter jam can cause engine trouble, because this should be safeguarded regularly, make the overhaul change when necessary.
