KR100191414B1 - Idle test of dignosis car by expert system - Google Patents

Abstract

The present invention relates to an electronic control unit (ECU) for detecting an abnormality of the idling mechanism during starting of an engine of an automobile and to provide a cause of the failure, analysis, confirmation, The present invention relates to a test method for failure diagnosis. In the present invention, the data and the normal reference value for determining the failure of the parts and sensors are accurately set in each failure diagnosis step, and the measured values at each step and the data and the normal reference value are compared with each other. And to clearly indicate the processing instructions for abnormal operation. The idling test method for fault diagnosis of an automobile by the expert system according to the present invention is a method for adjusting the idle switch, measuring the voltage of the coolant temperature sensor, measuring the terminal voltage of the battery and checking the charging device, Measurement of engine speed, measurement of injector surge, measurement of ignition primary voltage and current, measurement of vacuum degree, voltage measurement of motor position sensor, and so on are referred to as cooling water temperature sensor, vibration sensor, engine speed sensor, Sensor, etc., and stores the measured value. If there is an abnormality in the measured value, it is determined whether or not there is an abnormality, and the corresponding part is checked to solve the trouble of the abnormal part.

Description

Test method for fault diagnosis of automobile by expert system

FIG. 1 is a block diagram schematically showing a fault diagnosis system for an automobile including an electronic control unit and an expert system diagnosis unit; FIG.

FIG. 2 is a flow chart of a method for testing a vehicle for failure diagnosis by an expert system according to the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS

10: engine 11: knocking sensor

12: cylinder top dead center sensor (TDC) 13: cooling water on sensor (WTS)

14: Oxygen sensor 15: Engine speed sensor (CAS)

16: vehicle speed sensor (VSS) 17: motor position sensor (MPS), step motor (STM)

18: Vibration sensor 20: Electronic control unit (ECU)

24: Expert system diagnostic device 30: Suction part

31: Air cleaner 32: Throttle valve

33: Injector 34: Air flow sensor (AFS)

35: air temperature sensor (ATS) 36: atmospheric pressure sensor (BPS)

37: throttle position sensor (TPS) 39: idle switch

50: exhaust part 51: three way catalytic converter

52: EGR valve

The present invention relates to a method of diagnosing a malfunction of an automobile which diagnoses a malfunction of an automobile equipped with an electronic control unit and provides maintenance instructions for malfunctions. More particularly, The present invention relates to a test method for diagnosing a fault of an automobile by an expert system that diagnoses a failure, analyzes the cause of the failure, and confirms, checks, and resolves the failure.

In order to supply air and fuel into the cylinder of an automobile engine, a carburettor, which conventionally mixes the gasoline fuel sent from the fuel pump with air using a negative pressure generated by the inhalation action of the engine, was used. However, according to the mixing method of the fuel and the air by the carburetor, since the fuel is supplied into the cylinder through the intake manifold, the structure of the intake manifold, the difference in the suction length to each cylinder, , A decrease in responsiveness of the cylinder inflow, and a condensation phenomenon in the manifold of the fuel.

Recently, with the rapid development of the electronics industry, the computer industry, and the peripheral device technology, the latest technology has been applied to the fuel mixing by the fuel injection method that has been researched and developed so that the fuel is directly supplied to the intake manifold adjacent to the cylinder by the injector An electronically controlled fuel injection device is introduced. In accordance with the development of such technologies for automobiles, electronically controlled fuel injection devices will be adopted in all automobiles in the future.

In such an electronically controlled fuel injection device, an injection amount of fuel is determined by an electronic control device (hereinafter referred to as ECU). The ECU performs control of the ignition timing, dwell angle control, idling speed control, exhaust gas recirculation (EGR) control, and fuzzy control, as well as controlling the fuel injection amount with the input signals of various sensors. In order to perform this function, the engine of the vehicle and each corresponding position are provided with a cooling water temperature sensor (WTS), an air flow sensor (AFS), a throttle position sensor (TPS), a motor position sensor (MPS) ), An engine speed sensor or a crank angle sensor (CAS), a cylinder top dead center sensor (TDC), an atmospheric pressure sensor (BPS), an oxygen (O2) sensor, a vehicle speed sensor (VSS) , Various switch signals (IG, ST, A / T, P / N, A / C, IDLE, etc.) are input to the ECU.

FIG. 1 schematically shows a fault diagnosis system for an automobile including the engine and the ECU described above. Referring to FIG. 1, a fault diagnosis system for an automobile is basically composed of an engine 10, an intake unit 30, and an exhaust unit 50, and various sensors are installed at predetermined positions. These sensors are connected to the ECU 20 and the ECU 20 is operatively connected to the power supply units 21 and 22 and the expert system 24 and the like. The air cleaner 31 is positioned in the suction unit 30 and the throttle valve 32 and the injector 33 are positioned between the intake unit 30 and the engine 10 and air A flow sensor or MAP sensor 34, an air temperature sensor 35, an atmospheric pressure sensor 36, and a throttle position sensor 37 are mounted. The exhaust manifold 51 is provided with a three-way catalytic converter 51. The exhaust manifold 54 is communicated with the intake manifold 38 by the bypass passage 53, An EGR valve 52 is mounted at a predetermined position. A knock sensor 11, a cylinder top dead center sensor 12, a cooling water ON sensor 13, an engine speed sensor 15, a motor position sensor or a stem motor 17 are provided at predetermined positions adjacent to the engine 10, Respectively. All of the above sensors are connected to the ECU 20 as an electronic control device and the ECU 20 is connected to various input and output devices such as a battery power source 21, a backup power source 22, and an expert system diagnosis device 24 . And the oxygen sensor 14 and the vehicle speed sensor 16 located in the exhaust manifold 54 are connected to the ECU 20. [ The primary current measurement sensor 23, the secondary voltage measurement sensor 25, and the vibration sensor 26 are separately connected to the expert system diagnosis unit 24.

On the other hand, in order to diagnose and repair malfunctions in automobiles, the conventional maintenance manual subdivides breakdowns by types or problems, analyzes the cause, and suggests solutions. However, the symptoms related to the malfunction of the vehicle are not solely caused by one cause, especially the engine related trouble, and are caused by various complicated causes, and the malfunction is not solved by the one-to-one correspondence diagnosis method. Nevertheless, the failure diagnosis method which depends only on experience and sense is applied and the failure of the car can not be grasped accurately, so that the proper troubleshooting method is not provided. Particularly, when the fuel is supplied by the injector injection method and the automobile is controlled by the ECU through various sensors, due to the variety of causes of failure, the high degree of mechanical and electronic devices, and the complexity of problems, The fault diagnosis can not be accurately performed. Furthermore, if the fault is judged incorrectly, the problem of failure can not be solved, and a considerable amount of time and effort is wasted.

Accordingly, in recent years, a variety of scanners or scopes for diagnosis of faults have been used to diagnose faults in electronic control systems including ECUs and cope with them.

However, in the case of using the fault diagnosis equipment, the fault diagnosis flow can not be systematically provided, and there is an inconvenience that the vehicle maintenance person has to spend considerable effort and time to check the cause of the fault. In addition, in order to diagnose the failure of the electronic control system, knowledge of the structure and operation principle of the vehicle as well as the basic principles of the electronic circuit and circuit understanding must be provided. In the case of diagnosing a variety of various automobiles, various kinds of scanner data and normal reference values are presented in the maintenance manual of the corresponding vehicle, but this is only a general matter and can not be applied to professional fault diagnosis . In addition, since the normal reference values of various kinds of data have insufficient numerical values for precise fault diagnosis, it is difficult to trust the accuracy of the data. In the case where complex data is required, there is a problem that the discrepancy is further increased. It is time to invent an expert system because the deviations are so serious that misdiagnosis and re-occurrence occur.

The present invention has the same problems as the above-described conventional test method in performing the idle test as an idle test for grasping the presence or absence of failure of the vehicle caused by the idle or idle of the engine while the engine of the vehicle is idling.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a system and method for diagnosing faults, , It is necessary to precisely set the data and the normal reference value for judging the failure of the parts and sensors, compare the measured value at each step with the data and the normal reference value to determine the abnormality of the vehicle, And a method for testing a vehicle for fault diagnosis by an expert system. In order to achieve the above object, the present invention provides an idling test method for diagnosing an automobile by using a fault diagnosis device, comprising the steps of adjusting an idling speed to maintain a steady state, Measuring the terminal voltage of the battery so that the terminal voltage of the battery has a value in the range of 13.2V to 14.5V and checking the charging device if the terminal voltage is out of the range; Measuring the vibration sensor voltage of the engine, storing the result when the cylinder deviating from the average is triggered to be detected by the specific cylinder or not detected by the specific cylinder and the trigger can not be triggered; If the deviation is more than 5V or less than 5V, check for defective parts Measuring a secondary peak voltage for each cylinder for relative evaluation with a reference value; measuring an ignition primary current and absolute evaluation of the measured value; Measuring a spark duration time of the secondary waveform and an ignition secondary voltage for each cylinder and storing the result of the cylinder when the deviation of the ignition secondary voltage is higher or lower than 1000 V; Measuring the degree of vacuum of the engine; measuring the angular speed of each cylinder by triggering a cylinder top dead center sensor signal in idling to relatively evaluate the angular speed of the engine speed sensor with a reference value; To measure the surge, the number of steps of the stepper motor, and the revolution speed of the actuator, turn on the air conditioner switch, And then to provide an all-time test method for diagnosis of a car consisting of the off phase.

The revolving test method according to the present invention basically consists of fuel pressure test, injector precision test, engine auxiliary test, ignition device test, air flow sensor test, vacuum test, motor position sensor test, air condition switch test and step motor test.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of a test method for failure diagnosis by an expert system of an automobile according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a flowchart of an idle test method for diagnosing faults in an automobile according to the present invention. The second-degree phase (S1~S ₁₈₎ is deulyimyeo step of the whole constituting a revolving test method according to the invention, the step of _{(S 1, S 4 ~S 7} , S 9, S 10, S 13 ~ S ₁₆ , S ₁₈ ) constitute the essential steps of the present invention, and steps (S ₂ , S ₃ , S ₈ , S ₁₁ , S ₁₂ , S ₁₇ ) may be further included. The description of the steps S ₁ to S ₁₈ will be sequentially described in order.

Referring to FIG. 2, firstly, as the first step (S ₁ ), the adjustment of the idling speed should be normal. This is because the diagnosis is sure to be made if the idling adjustment is normally performed. In other words, idle speed control is only done by the operator with basic machine setting work. If the idle speed is not adjusted for the first time, a wrong judgment may occur when the idle speed differs due to other disturbance factors.

The following step (S _2), the adjustment of the idle switch status measures the potential of the idle switch is less than or equal to 1V. The type without idle switch is based on the idle reference value potential of the throttle position sensor. If the adjustment state of the idle switch is 1 V or more, the idle switch is turned off. At this time, it is checked whether the accelerator cable is tight or the idle switch is adjusted properly.

In the next step (S ₃ ), if it is confirmed that the engine is started, the voltage of the coolant temperature sensor is measured and stored at intervals of 10 seconds.

In the following step (S _4), and compares the cooling water temperature sensor based on the measured temperature of the engine oil temperature sensor, and the measured value of the temperature sensor. If the temperature is below 80 ° C, it is not working yet. If the engine temperature and the coolant temperature differ by more than 10 °, check the engine temperature and coolant temperature input to the electronic control unit.

In the next step (S ₅ ), the terminal voltage of the battery is measured. As a result of the measurement, if the battery terminal voltage is 13.2 V or less or 14.5 V or more, the charging device is defective.

After the step S ₅ , it is determined whether or not the reference point of the engine speed sensor CAS matches the cylinder top dead center # 1 TDC in the case of a vehicle of ALPHA and SIEMNS type . At this time, the center of the top dead center must coincide at the second down point of the reference point of the engine speed sensor (CAS). Since one cycle of the engine speed sensor (CAS) is 6 degrees apart, When incurred, make a discrepancy.

And the next step (S _6), the preparation according to the model to a predetermined value at the time of revolution and measuring the fuel pressure. If the measured fuel pressure is lower than the specified value, check whether the fuel pump relay or the control relay is applying power to the fuel pump during cranking. Then check the fuel pump status and fuel pump wiring connector, check the filter, Check for clogging or bending of the fuel filter. If the fuel filter is clogged, be sure to replace the fuel filter. If the fuel pressure is higher than the specified value, check the fuel pressure regulator, fuel return pipe or hose.

In the next step (S ₇ ), the vibration sensor voltage of the engine is measured. If the measured voltage is outside the average value of the measured vibration voltage at the time of normal revolutions per vehicle type, number of cylinders, and exhaust amount, the cylinder is triggered and the result is stored in a specific cylinder. And if the measured voltage deviates from the average, the result is stored if the cylinder is not detected by the specific cylinder and the trigger is not detected and moves irregularly.

The following step (S _8), the trigger signals from the engine speed sensor (CAS) a cylinder top dead center sensor (TPS) from the idle to evaluate the prepared reference value and the relative angular velocity of the angular velocity measured by each cylinder. At this time, the measurement of 8 cycles is repeated four times. The angular velocity deviation is the total average of the measured data is 100, and a specific cylinder is generated that deviates from the normal deviation value and stores the measured value of the cylinder. At this time, the deviation value is a value obtained by adding 20% of the angular speed deviation of the normal engine-the maximum value and the minimum value. Also, when the angular velocity deviation does not become the trigger but the reference can not be grasped even though there is a cylinder deviating from the normal deviation value and the reference angular velocity average is 100, the result is stored.

In the next step (S ₉ ), the injector surge is measured to evaluate the injector surge relative to the reference value. If the measurement result shows that the injector surge is more than 5V or less than 5V, there is a problem with the injector and related parts. If the deviation is more than 5V, the injector is inadequate or the wiring contact is wrong. If the deviation is less than 5V, there is an abnormality in the power supply part of the injector such as the control relay. At this time, if you want to make precise diagnosis, test the injector manually.

In the cranking test, a specific cylinder deviating from the deviation value occurs by evaluating the angular speed of the engine speed sensor relative to each cylinder relative to each other, and the injector surge is relatively evaluated in the idling test. When the specific cylinder occurs, the results of the specific cylinders are inconsistent , at the same time a certain cylinder in the cranking relative evaluation of the angular velocity of the engine rotation speed sensor for each cylinder in the test by the lower cylinder generating the compression pressure and the step (S ₇₎ the trigger certain cylinder and the step in the (S ₈₎ The cause of the engine collision is that the compression pressure of the cylinder is poor.

Then, the size by evaluating the angular velocity of the engine rotation speed sensor (CAS) for each cylinder in the ranking test is relatively not occur with low compression pressure cylinder 21, the step (S ₇₎ the trigger certain cylinder and the step in the (S ₈ ) And the deviation of the injector surge is 5 V or less in the step S ₉ , the cause of the engine collision is that the injector of the cylinder is poor. In this case, the injector line and the injector of the cylinder should be checked.

In the next step (S ₁₀ ), the secondary peak voltage is measured for relative evaluation with the reference value for each cylinder. At this time, if there is a cylinder with a lower secondary peak voltage, the result is stored.

To the next step (S _11), to measure the ignition primary voltage. If the ignition primary voltage is lowered, it will cause engine failure and start failure. At this time, since the connector is defective or the ignition coil is defective, check whether there is a voltage drop between the + terminal of the ignition coil and the + terminal of the battery.

To the next step (S _12), measures the base voltage of the power transistor. If the measured base voltage of the power transistor is 3.7 V or higher, check the grounding of the earth-side emitter wiring because the ground state of the emitter of the power transistor is bad. If the base voltage of the power transistor is 3.4 or less, the ignition coil is defective or the power transistor itself is defective.

In the next step ( _S13 ), the ignition primary current is measured and evaluated in absolute terms. When the measured ignition primary current is lower than normal and the base voltage of the power transistor is 3.4 V or lower, it is judged that the wiring of the ignition primary is poor. Conversely, if the primary current is higher than normal, it is regarded as a failure of the power transistor.

To the next step (S _14), and measure the second flame duration and secondary ignition voltage of the secondary waveform for each cylinder and a reference value and the relative evaluation. If the deviation of the ignition secondary voltage is higher or lower than 1000V, the result of the cylinder is stored. If the low-pressure deviation is more than 1000V, check that the gap adjustment of the spark plug is too large as a whole, or that the heat of the plug does not meet the specified value. If there is no abnormality at this time, it means that the engine is totally lean. On the other hand, if the voltage deviation is lower than 1000V, the gap adjustment of the ignition plug is made too small as a whole or the heat value of the plug does not meet the specified value. If there is no abnormality at this time, it means that the engine has an overall dense indication.

On the other hand, in the case of a single phase rover head camshaft of the engine system (S ₁₄₎ an ignition voltage less than 1000V. 2 the deviation of the difference in measured and unstable flame duration of all cylinders, and that the deviation is more than 0.3mS 0.5mS or less when the It is judged that the ignition secondary high-voltage line portion is defective. At this time, the spark plug is expected to be contaminated as a whole or the engine oil is burned, and the valve guide seal state as a whole is also checked. It may be a break in the high-voltage line between the ignition coil and the distributor. There may be uneven wear of the rotor electrode, and it is also checked whether the assembly of the distributor cap is poor. In addition, the high-voltage leakage from the ignition coil to the distributor is inspected.

When the deviation of the duration of the flame is extremely high only for a specific cylinder and the difference in ignition duration with other cylinders is 0.5 mS or more, it is determined that the secondary voltage of the cylinder is irregular.

At this time, check for breakage or short circuit inside the high-voltage line of the cylinder, and check dust, cracks, and moisture inside the distributor cap. Check the spark plug contamination of the cylinder, and check the cause of engine oil combustion and valve guide seal and jet valve.

It is judged that the plug gap of the cylinder is large when the ignition secondary voltage of the specific cylinder is higher than that of the normal ignition secondary voltage of the other cylinder by 1000V or more and at the same time, When the ignition secondary voltage of a specific cylinder is lower than 1000V and the flame duration is longer than 2mS, the plug gap of the cylinder is judged to be small.

On the other hand, in the case of a melco type vehicle, the frequency and duty of the air flow rate sensor are measured at the same time per cycle of the engine speed sensor (CAS), and when there is no additional factor, the duty value is in the range of 50 ± 20% It is judged that the air flow rate sensor itself or the wiring relation is poor when the frequency is separated by 3 Hz or more. If the frequency of the air flow sensor deviates by more than 5 Hz during idling, it is determined that an inadequate air flow sensor is used. In the above, the addition factor means a state where the cooling fan operates, the air conditioner is operated, the handling is performed, the electric load is applied, and the frequency and the duty are not judged when there are additional factors.

To the next step (S _15), jingongdoeul measured, and the measured vacuum degree is low, and store the result.

To the next step (S _16), to trigger the signal of the cylinder top dead center sensor (TPC) from the idle to the engine speed sensor to evaluate the angular velocity of the reference value prepared (CAS) and the relative angular velocity of each cylinder is measured. At this time, measurement of 8 cycles is repeated four times. The angular velocity deviation is the total average of the measured data is 100, and deviates from the normal deviation value and stores it when it is not a specific cylinder. At this time, the deviation value is a value obtained by adding 20% of the angular speed deviation of the normal engine-the maximum value and the minimum value.

If the injector surge falls within the proper range, the secondary peak voltage of each cylinder is normal, the duty value and frequency of the air flow sensor are within the proper range, and the cylinder in which the vibration sensor voltage of the engine deviates from the average value is detected And the angular velocity deviation of the engine speed sensor deviates from the normal deviation value when the overall average of the measured data is 100, and it is judged that the injector wiring is wrong when the cylinder is not a specific cylinder. If the wiring between the injectors is changed, there will be a problem in the engine, so check that the wiring between the electronic control unit (ECU) wiring and the injector of each cylinder is wrong.

Check the next step (S ₁₇₎ Rohan hand, if the voltage of the motor position sensor at least 1.8V on the idling is the air conditioning switch is turned on and, if the air conditioning switch is turned on and the air conditioning switch is turned off. If the voltage of the motor position sensor becomes 1.25V or more under the condition that the load is not applied, check whether the accumulation of carbon in the throttle body or the idling adjustment is correct.

A bad cylinder results in a bad result, and a bad cylinder of 2% or more in the relative evaluation of the angular speed of the engine speed sensor (CAS) at the time of cranking and a bad cylinder of the result of relative evaluation of the flame duration in idling are the same, If the specific cylinder detected by the cylinder whose voltage is outside the average is triggered and the angular speed deviation of the engine speed sensor (CAS) is a cylinder that deviates from the normal normal value when the overall average of the measured data is 100, It is determined that the pressure is poor. At this time, check the valve condition of the cylinder, automatic gap adjuster, piston ring, head, gasket, etc., because they are defective.

The angular speed of the specific cylinder and the engine speed sensor (CAS), which is triggered by a cylinder in which the injector surge is 5V or more, the degree of vacuum is ± 50mHG or more irregularly or lower than the reference value, It is determined that the assistant driver is on the injector line when the specific cylinder whose angular speed deviation deviates from the normal deviation value matches and the compression pressure of the specific cylinder is good. In this case, check whether the injector is suitable, and check the contact state of the wiring.

Next, the degree of vacuum is about 50 mHG lower than the reference value, and the angular speed deviation of the specific cylinder and the engine speed sensor (CAS), which are detected by the cylinder whose vibration sensor voltage is deviated from the average value, It is judged that there is an abnormality in the ignition device when the specific cylinder outside the numerical value and the specific cylinder having the residual pressure deviation of the ignition secondary voltage equal to or more than 1000 V are all in good condition and the cause of the collision is not in the injector line do. At this time, the cylinder high-voltage voltage is irregular, and the gap of the plug of the cylinder is abnormal. Check the inside of the cylinder high-voltage line for damage, and check dust, cracks and moisture inside the distributor cap. Also, check the cylinder spark plug for contamination and check the cause of engine oil combustion and valve guide seal and jet valve. In addition, when the ignition secondary voltage of the cylinder is high or low, the plug gap is often caused by excessive or inadequate plugging.

It turns on and off for the next step (S _18), 2 seconds, the air conditioner switch. Then, the voltage of the motor position sensor, the stepping motor, the step number of the stepping motor, and the speed of the idling speed actuator are measured. If the measured value of the motor position sensor is more than 1.8V or the minimum value is more than 1.25V, it is judged that there is accumulation of carbon in the throttle body or the idling adjustment is wrong and check the abnormal condition. If the maximum value of the motor position sensor is less than 1.6V or the minimum value is less than 0.9V, the idling adjustment is wrong, or check the power and wiring of the motor position sensor.

Next, the measured step motor is analyzed. When the stepping motor is not worn and the number of revolutions of the engine does not rise with respect to the step motor type vehicle applied to the double overhead camshaft (DOHC) MELCO type, since there is an abnormality in the step motor driving circuit, Is not working. At this time, check the wiring and connectors of the step motor for any abnormality in the electronic control unit (ECU). When the surge of the step motor is irregular, it is because the step motor is irregular. Therefore, the step motor is disassembled and cleaned or replaced because the rust is formed in the bearing of the step motor. If the number of revolutions of the motor does not increase proportionally, the step motor wiring is incorrect. Check the wiring sequence and take corrective measures.

Next, the number of steps of the measured step motor is analyzed. If the stepping motor maximum step is more than 80 steps or the minimum step is more than 25 steps, check the carbon on the step motor side because the number of steps is too high. If the maximum stepping speed of the stepping motor is less than 60 steps or the lowest step is less than 10 steps, the number of steps is too low, so that the number of revolutions of the engine may decrease.

Next, the voltage of the stepper motor is analyzed. When the voltage of the step motor exceeds 20V, the maximum voltage is 30.0 ± 0.4V or less. When the voltage of the step motor exceeds 20V, a voltage of 16V to 17.4V or less occurs at 6mS ± 1mS, When a voltage of 13.7 V to 19 V or less occurs from 13 ms to 13.7 mS from a point when the voltage exceeds 20 V or when a voltage of 14.3 V to 14.7 V or less occurs from 19 ms to 20 ms at a point where the voltage of the step motor exceeds 20 V Since the bearing of the step motor is bad, disassemble and clean or replace the step motor.

Next, for the vehicle using the idle speed actuator (ISA), the speed of the idle speed actuator (ISA) is analyzed. When there is no surge of the idle speed actuator, the idle speed actuator has an abnormal driving circuit. Therefore, it is checked whether the wiring between the electronic control unit (ECU) and the idle speed actuator (ISA) Check whether the device is bad or the air conditioner signal is input. If the engine speed is not increased in proportion to the increase of the duty although the idle speed actuator writes, the wiring of the idle speed actuator is wrong, so check it and take action.

Next, the duty of the idle speed actuator is analyzed. If the maximum duty is between 40% and 47% and the maximum duty is between 25% and 40%, the duty of the idle speed actuator is defective.

Combining the above test steps, the ignition is poor if the specific cylinder in which the abnormality is found as a result of the measurement of the secondary peak voltage and the specific cylinder in which the abnormality is found as a result of the measurement of the spark duration time and the ignition secondary voltage are found. On the other hand, if the secondary peak voltage, the flame duration, and the ignition secondary voltage do not match the abnormal cylinder and injector surge deviation cylinder, then the injector and injector related parts are bad. In addition, when a cylinder whose vibration sensor voltage of the engine deviates from the average value is not detected by a specific cylinder without being abnormal, and is not triggered and moves irregularly while at the same time, the angular speed of the engine speed sensor (CAS) If the trigger does not work even if the angular velocity deviates from the normal deviation value, and the reference can not be determined, there is a problem with the vibration.

As described above in detail, in the test method for fault diagnosis of an automobile by the expert system according to the present invention, the data and the reference value, which are the criteria of the fault judgment, are accurately set and the fixed diagnosis is performed systematically and precisely, There is a remarkable effect that it is possible to judge whether or not the vehicle is malfunctioning and can quickly and accurately solve the malfunction of the automobile against abnormal operation.

Claims (10)

An idling test method for diagnosing a malfunction of an automobile by means of a fault diagnosis apparatus, comprising the steps of: (S ₁ ) adjusting an idle speed to maintain a steady state; Comparing the temperature of the engine oil with a temperature sensor and comparing it with a coolant temperature sensor based on the temperature sensor value (S ₄ ); Measuring the terminal voltage of the battery so that the terminal voltage of the battery has a value in the range of 13.2V to 14.5V and checking the charging device if the value is out of the range (S ₅ ); Measuring the fuel pressure in order to check whether the appropriate predetermined value (S ₆₎ and; Measuring the vibration sensor voltage of the engine and storing the result when the cylinder deviating from the average is triggered to be detected by the specific cylinder or not detected by the specific cylinder and can not be triggered (S ₇ ); (S ₉ ) measuring the injector surge for each cylinder in order to check the defective portion when the deviation is not less than 5V or not more than 5V, and comparing the injector surge with the reference value; (S ₁₀ ) measuring a second peak voltage for each cylinder for relative evaluation with a reference value; Measuring an ignition primary current and evaluating the measured value (S ₁₃ ); Measuring the spark duration time and the ignition secondary voltage of the secondary waveform for each cylinder for relative evaluation with the reference value and storing the result of the cylinder when the deviation of the ignition secondary voltage is higher or lower than 1000 V ₁₄ ); Measuring a degree of vacuum in order to evaluate the reference value and the relative (S ₁₅₎ and; A step of triggering a cylinder top dead center sensor signal in the idle measuring the angular velocity of each cylinder in order to evaluate the angular velocity reference value of the engine speed sensor and the relative (S ₁₆₎ and; Voltage of the motor position sensor, the stepping motor written, the number of steps of the stepper motor, of the vehicle by the expert system of the step (S ₁₈₎ that turns on and after a certain period of time off the air conditioner switch, to measure the surge of the revolution speed actuator Testing method for fault diagnosis. The method of claim 1, wherein the step (S ₁₎ and the step (S ₄₎ in the adjusted state of the idle switch between measuring the potential of the idle switch is less than or equal to 1V, and adjust the idle switch if more than 1V (S ₂ )Wow; A step (S ₃₎ for measuring the voltage of the cooling water temperature sensor, and stores the measured value, and further; Step (S ₇₎ and the step (S ₉₎ in order to evaluate the reference value and the relative angular velocity of the engine rotation speed sensor (CAS) between triggers the cylinder top dead center sensor signal in the idling step of measuring the angular velocity of each cylinder (S ₈₎ Lt; / RTI > Phase step (S ₁₁₎ measuring a first voltage between the lighting (S ₁₀₎ and the step (S ₁₃₎ and; Measuring the base voltage of the power transistor so that the base voltage of the power transistor has a range from 3.4 V to 3.7 V, and checking a bad position if the value is out of the range (S ₁₂ ); Check whether the voltage of the motor position sensor is 1.8 V or more in the state that the air conditioner switch is on between step S ₁₆ and step S ₁₈ and check whether the voltage of the motor position sensor is 1.25 V or more in the state where no load is applied ( _S17 ) of measuring the voltage of the motor position sensor in order to determine whether or not the vehicle is running. The method according to claim 1, further comprising, after the step (S ₅ ), determining whether the reference point of the engine speed sensor and the cylinder top dead center coincide with each other in the case of an alpha and jimez type vehicle Testing methods for fault diagnosis of automobiles. According to claim 1 or 2, wherein the single overhead and camshaft method steps in the case of the engine (S ₁₄₎ the ignition variation of the secondary voltage measured at less than 1000V of unstable flame duration of all cylinders and the deviation Is less than or equal to 0.3 mS and less than or equal to 0.5 mS, it is determined that the ignition secondary high-voltage line portion is defective. According to claim 1 or 2, wherein the step (S ₁₄₎ in a particular cylinder only when at least the extreme variation in the spark duration, and the difference between the ignition 0.5mS duration of the other cylinder to the secondary voltage of the cylinder are irregularly Testing Method for Automotive Fault Diagnosis by an Expert System to Judge. Claim 1 or claim 2, wherein the step (S ₁₄₎ is high or higher than the 1000V secondary ignition voltage of the secondary ignition voltage of the specific cylinder the normal spark duration at the same time the other cylinder in a constant state of short below 0.8mS It is determined that the plug clearance of the cylinder is large when the ignition secondary voltage of the specific cylinder is lower than 1000 V and the flame duration is longer than 2 mS and has a stable value continuously. Test method for fault diagnosis of automobile by expert system. According to claim 1 or 2, wherein the step (S ₁₄₎ for the Melco type vehicle in comparison with a reference value when measuring the frequency and the duty of the air flow sensor in one cycle of the engine speed sensor at the same time and there are no additional factors It is judged that the air flow sensor itself or the wiring relation is poor when the duty value deviates from the range of 50 ± 20% and the frequency deviates from 3 Hz. If the frequency of the air flow sensor deviates by more than 5 Hz, an inadequate air flow sensor Test method for fault diagnosis of automobiles by an expert system judged to be. The method of claim 1 or 2, wherein the degree of vacuum measured in step (S ₁₅ ) is less than 570 ± 30 mHg. The method of claim 1, wherein the step (S ₁₈₎ in the case of a single overhead cam shaft of the engine system after a signal of engine idle control motor is output more than 10V, and that the measured high of 1.6V of the motor position sensor output in a predetermined time And measuring a maximum value and a minimum value of the motor position sensor. The method of claim 1, wherein in the step (S ₁₈₎ measuring the number of steps of the step motor and the or at least up to the step 80 a step is above the lowest step 25 the step is too high step can first check the carbon of the stepper motor side, A method for testing a motor for failure diagnosis of an automobile by an expert system judging that idling is poor if the maximum step is 60 steps or less or the minimum step is 10 steps or less.