JPH0135180B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a failure diagnosis device for an ignition system in an automobile gasoline engine, etc., which is equipped with an engine control device equipped with a microcomputer. As interest in depleting environmentally friendly energy resources increases by preventing air pollution, a control device that comprehensively controls the operating conditions of automotive gasoline engines to improve exhaust gas conditions and improve the fuel ratio. As a result, microcomputers are being used to collect signals from sensors that provide various data that represent the operating status of the engine, such as a cooling water temperature sensor and an _O2 sensor that provides the oxygen concentration in exhaust gas. The electronic engine control device (EEC) performs various controls such as fuel intake, fuel supply amount, ignition timing, exhaust gas recirculation amount, and idle speed, so that the optimal engine operating condition is always obtained. It has come to be used. An example of a system in which such EEC is applied to a fuel injection type internal combustion engine is shown in FIGS. 1 to 6. Fig. 1 is a partial cross-sectional view schematically showing the entire engine control system.
6 and is supplied to cylinder 08. The gas burned in the cylinder 08 passes through the exhaust pipe 10 from the cylinder 08 and is discharged into the atmosphere. The throttle chamber 04 is provided with an injector 12 for injecting fuel, and the fuel injected from the injector 12 is atomized within the air passage of the throttle chamber 04 and mixed with intake air. A mixture is formed, and this mixture is supplied to the combustion chamber of the cylinder 08 through the intake pipe 06 when the intake valve 20 is opened. A throttle valve 14 is located near the outlet of the injector 12.
16 are provided. The throttle valve 14 is configured to be mechanically interlocked with the accelerator pedal and is driven by the driver. On the other hand, the throttle valve 16 is arranged so as to be driven by the diaphragm 18, and is fully closed when the air flow rate is small.As the air flow rate increases, the negative pressure on the diaphragm 18 increases, so that the throttle valve 16 It begins to open and suppresses the increase in inhalation resistance. An air passage 22 is provided upstream of the throttle valves 14 and 16 of the throttle chamber 04, and this air passage 22 includes a thermal air flow meter consisting of an electric heating element,
That is, a flow rate sensor 24 is provided, and an electric signal AF that changes depending on the air flow rate determined from the relationship between the air flow rate and the amount of heat transferred from the heating element is taken out. Since the flow rate sensor 24 made of this heating element (hot wire) is installed in the bypass air passage 22, it is protected from high-temperature gas generated when the cylinder 08 backfires, and it is also protected from being contaminated by dust in the intake air. It is also protected from. The outlet of this bypass air passage 22 is opened near the narrowest part of the bench lily, and the inlet thereof is opened on the upstream side of the bench lily. Fuel supplied to the injector 12 is supplied from a fuel tank 30 to a fuel pressure regulator 38 via a fuel pump 32, a fuel damper 34, and a filter 36. On the other hand, pressurized fuel is supplied from the fuel pressure regulator 38 to the injector 12 via a pipe 40.
The fuel pressure regulator 38 is connected to the fuel tank 3 so that the difference between the pressure in the intake pipe 06 through which fuel is injected and the fuel pressure to the injector 12 is always constant.
Fuel is returned to zero via a return pipe 42. The air-fuel mixture taken in from the intake valve 20 is transferred to the piston 5.
0 and is combusted by a spark from the ignition plug 52, and this combustion is converted into kinetic energy. The cylinder 08 is cooled by cooling water 54, the temperature of this cooling water is measured by a water temperature sensor 56, and this measured value TW is used as the engine temperature. A high voltage is supplied to the spark plug 52 from an ignition coil 58 in accordance with the ignition timing. Further, the crankshaft (not shown) is provided with a crank angle sensor that outputs a reference angle signal and a position signal at every reference crank angle and every fixed angle (for example, 0.5 degrees) according to the rotation of the engine. The output of this crank angle sensor, water temperature sensor 56
output signal TW and electrical signal from heating element 24
The AF is inputted to a control circuit 60 consisting of a microcomputer or the like and subjected to arithmetic processing, and the output of this control circuit 60 drives the injector 12 and the ignition coil 58. Furthermore, the throttle chamber 04 has a throttle valve 1.
A bypass 26 is provided that straddles the intake pipe 6 and communicates with the intake pipe 06, and this bypass 26 is provided with a bypass valve 61 that is controlled to open and close. This bypass valve 61 faces the bypass 26 provided by bypassing the throttle valve 16, and is controlled to open and close by a pulse current, and the cross-sectional area of the bypass 26 is changed depending on the amount of lift. The drive section is driven and controlled by the output of the control circuit 60. That is, the control circuit 60 generates an opening/closing periodic signal for controlling the driving section, and the driving section adjusts the lift amount of the bypass valve 61 based on this opening/closing periodic signal. Therefore, the injector 12 shown in FIG. 1 is controlled to control the air-fuel ratio (A/F) and fuel increase control, and the bypass valve 61 and the injector 12 control the engine speed at idle (ISC).
Do this. FIG. 2 shows an ignition system in which a pulsed current is supplied to a power transistor 64 through an amplifier 62, which turns the transistor 64 on. As a result, the ignition coil 58 from the battery 66
Primary coil current flows to. When the input pulse current falls, the transistor 64 is cut off, and
A high voltage is generated in the secondary coil of the ignition coil 58. This high voltage is distributed via the power distributor 70 to each of the spark plugs 52 in each cylinder of the engine in synchronization with the engine rotation. FIG. 3 is for explaining an exhaust gas recirculation (EGR) system, in which constant negative pressure from a negative pressure source 80 is applied to a control valve 86 via a pressure control valve 84. The pressure control valve 84 controls the ratio of the negative pressure of the constant negative pressure source to the atmosphere 88 according to the ON duty ratio of the repeated pulses applied to the transistor 90, and controls the state of application of the negative pressure to the control valve 86. Therefore, the negative pressure applied to the control valve 86 is caused by the transistor 90
The controlled negative pressure of the pressure control valve 84, which is determined by the ON duty ratio of
EGR amount is controlled. Figure 4 is an overall configuration diagram of a control system using a microcomputer, which includes a central processing unit 102 (hereinafter referred to as CPU), a read-only memory 104 (hereinafter referred to as ROM), and a random access memory 106 (hereinafter referred to as ROM). (referred to as RAM) and an input/output circuit 108.
The CPU 102 calculates input data from the input/output circuit 108 using various programs stored in the ROM 104, and returns the calculation results to the input/output circuit 108 again. RAM 106 is used for intermediate storage necessary for these operations. CPU102,
ROM104, RAM106, input/output circuit 108
Exchange of various data between them is performed by a bus line 110 consisting of a data bus, a control bus, and an address bus. The input/output circuit 108 includes a first analog-to-digital converter 122 (hereinafter referred to as ADC1).
and a second analog-to-digital converter 12
4 (hereinafter referred to as ADC 3) and angle signal processing Hanaji 1
26 and a discrete input/output circuit 128 (hereinafter referred to as DIO) for inputting and outputting 1-bit information. ADC1 has a battery voltage detection sensor 132
(hereinafter referred to as VBS) and cooling water temperature sensor 56 (hereinafter referred to as VBS)
(hereinafter referred to as TWS) and atmospheric temperature sensor 136 (hereinafter referred to as TAS)
), the adjustment voltage generator 138 (hereinafter referred to as VRS), and the throttle angle sensor 140 (hereinafter referred to as θTHS)
The outputs of the O ₂ sensor 142 (hereinafter referred to as O ₂ S) are added to the multiplexer 162 (hereinafter referred to as MPX), and the MPX 162 selects one of them and performs analog/digital conversion. The signal is input to a circuit 164 (hereinafter referred to as ADC). ADC1
The digital value that is the output of 64 is stored in register 166.
(hereinafter referred to as REG). In addition, the negative pressure sensor 144 (hereinafter referred to as VSC)
It is input to the ADC2, 124, is converted into a digital signal via the analog-to-digital conversion circuit 172 (hereinafter referred to as ADC), and is converted into a register 124 (hereinafter referred to as ADC).
REG). The angle sensor 146 (hereinafter referred to as ANGS) outputs a signal indicating a reference crank angle, for example, 180 degrees crank angle (hereinafter referred to as REF), and a signal indicating a minute crank angle, for example, 1 degree crank angle (hereinafter referred to as POS). The signal is applied to the signal processing circuit 126, where the signal is waveform-shaped. DIO 128 includes an idle switch 148 that operates when the throttle valve 14 returns to the fully closed position.
(hereinafter referred to as IDLE-SE), top gear switch 150 (hereinafter referred to as TOP-SW), and starter switch 152 (hereinafter referred to as START-SW)
is entered. Flow rate sensor 24 (hereinafter referred to as AFS) is ADC2
is input to analog/digital/conversion circuit 1
72 (hereinafter referred to as ADC), it is digitally converted and set in a register 174 (hereinafter referred to as REG). Next, the pulse output circuit and control target based on the calculation results of the CPU will be explained. The injector control circuit (denoted as INJC) is a circuit that converts the digital value of the calculation result into a pulse output. Therefore, a pulse with a pulse width corresponding to the fuel injection amount
INJ is made with INJC1134, AND gate 11
36 to the injector 12. The ignition pulse generation circuit 1138 (hereinafter referred to as IGNC) has a register (hereinafter referred to as ADV) for setting the ignition timing and a register (hereinafter referred to as DWL) for setting the primary current energization start time of the ignition coil.
These data are set by the CPU. Generates a pulse IGN based on the set data,
AND gate 11 to amplifier 62 detailed in FIG.
Apply this pulse ICN via 40. The opening rate of the bypass valve 61 is determined by the control circuit (hereinafter referred to as
ISCC) 1142 to AND gate 1144
is controlled by a pulse ISC applied via. ISCC 1142 has a register ISDC for setting the pulse width and a register ISCP for setting the repetition pulse period. The EGR amount control pulse generation circuit 180 (hereinafter referred to as EGRC) that controls the transistor 90 that controls the EGR control valve 86 shown in FIG. 3 has a register that sets a value representing the pulse duty.
It has EGRD and a register EGRP for setting a value representing the pulse repetition period. This EGRC
The output pulse EGR of is applied to transistor 90 via AND gate 1156. Further, the 1-bit input/output signal is controlled by the circuit DIO128. IDLE-SW as input signal
signal, TOP-SW signal, and START-SW signal. Further, the output signal includes a pulse output signal for driving the fuel pump. This DIO has a register DDR192 for determining whether the terminal is used as an input terminal or an output terminal,
Register DOUT for latching output data
194 are provided. The mode register 1160 is a register (hereinafter referred to as MOD) that holds instructions for commanding various states inside the input/output circuit 108. For example, by setting an instruction in the mode register 1160, the AND gates 1136, 1140, 1144,
All 1156 are activated or deactivated. Like this MOD register 11
By setting the command to 60, INJC and
You can control the stop and start of IGNC and ISCC output. As mentioned above, DIO 128 is a 1-bit signal input/output circuit, and is a register (hereinafter referred to as DDR) 1 that holds data for determining input or output.
Register 1 to hold the data to be output as 92
94 (hereinafter referred to as DOUT). This DIO 128 outputs a signal DIO0 for controlling the fuel pump 32. FIG. 5 is a program system diagram of the control circuit of FIG. 4. When the power is turned on by a key switch (not shown), the CPU 102 enters a start mode and executes an initialization program (INITIALIZ) 204. Next, run the monitoring program (MONIT) 206 and execute the background job (BRCK GROUND JOB 2).
Execute 08. This background job includes, for example, the EGR amount calculation task (hereinafter referred to as EGR
CAL TASK) and a calculation task (hereinafter referred to as FISC) for the bypass valve 61 and injector 12 during warm-up operation. During the execution of this TASK, if an interrupt factor (hereinafter referred to as IRQ) occurs,
From the IRQ disclosure step 222, an IRQ factor analysis program 224 (hereinafter referred to as IRQ ANAL) is executed. This IRQ ANAL program is further
ADC1 end interrupt processing (hereinafter referred to as ADC1 FND
It consists of the ADC2 interrupt processing (hereinafter referred to as INTV IRQ) program and the engine stop interrupt processing (hereinafter referred to as FNST IRQ) program, and is used for tasks required to start each task described later. Each startup request (below
(written as QUEUE). Each program ADC1END IRQ226 and ADC2END in this IRQ ANAL program 224
Each task for which a QUEUE is issued by each program of IRQ228 or INTV IRQ230 has a level
Zero task group 252 and level 1 task group 254
and level 2 task group 256 and level 3 task group 2
58, or a task constituting the task group. Also ENST IRQ Program 232
The task in which QUEUE occurs is the engine stop processing task 262 (hereinafter referred to as ENST TASK). When this ENST TASK 262 is executed, the control system enters the start mode again and returns to the starting point 202. The task scheduler 242 sets the execution order of the tasks so that they are executed starting with the task in which the QUEUE is occurring or the task with the highest level among the tasks whose execution has been interrupted (here, level zero is the highest). decide. When the execution of the task group is completed, the completion report program 260 (hereinafter referred to as EXIT) reports the completion. Based on this completion report, the task group with the highest level among the task groups waiting for execution is executed next. When there are no more suspended tasks or QUEUE tasks, the task scheduler 242
The process then moves on to executing the background job 208 again. Furthermore, if an IRQ occurs while any of the level 0 task group to level 3 task group is being executed, the process returns to the starting point 222 of the IRQ processing program. Table 1 shows the activation of each task and its functions.

[Table] In this Table 1, IRQ ANAL
There are programs, TASK SCHDULER, and EXIT. These programs (hereinafter referred to as OS) are held at addresses A000 to A300 of the ROM 104 as shown in FIG. In addition, as a level zero program
AD1IN, AD1ST, AD2IN, AD2ST, RPMIN
There are various programs, usually INTV IRQ 10 [m
SEC]. There are INJC, IGNCAL, and DWLCAL programs as level 1 programs, which are activated every 20 [mSEL] of INTV IRQ. A level 2 program is the LAMBDA program, which is activated every 40 [mSEC] of INTV IRQ. HOSEI as a level 3 program
There is a program and the INTV IRQ is 100 [mSEC]
is started every time. There are also EGRCAL and FISC programs as background jobs.
The above level zero program is PROG1 at address A70 of ROM104 in Figure 6.
It is stored in AAFF from 0. The level 1 program is the address of ROM104 as PROG2.
It is stored from AB00 to ABFF. level 2
The program is stored as PROG3 in addresses AE00 to AEFF of the ROM 104. The level 3 program is stored as PROG4 at addresses AF00 to AFFF in the ROM 104.
Also, background job programs are held from B000 to B1FF. In addition, the start address lift of each program from the above programs PROG1 to PROG4 (hereinafter
SETMR) is held from B200 to B2FF, and values representing each program activation cycle from PROG1 to PROG4 (hereinafter referred to as TTM) are stored at addresses B300 to B3FF. Other data is stored at addresses B400 to B4FF of the ROM in FIG. 6 as necessary. Following that, data ADV.MAP and AF for calculation.
MAP and EGR.MAP are memorized respectively. Note that a detailed explanation of other operations will be omitted. Thus, according to the EEC mentioned above,
Almost all controls related to the engine, such as A/F control, can be appropriately performed, and not only can strict exhaust gas regulations be fully met, but also an engine with an excellent fuel ratio can be obtained. By the way, in general, when a car or other vehicle becomes malfunctioning due to a malfunction, it is extremely rare for the user to find the malfunctioning part and perform repairs or inspections on his/her own; in most cases, the user will have to request a repair shop to do the work. It is customary to find the malfunctioning part, repair it, and inspect it. However, as mentioned above, automobile engines equipped with EEC use a large number of various sensors and actuators, and their failure modes are diverse and diverse, and failures are rarely obvious from the outside. When a failure occurs, it is extremely difficult to identify the location where the failure occurred. In addition, many malfunctions can only be discovered when the engine operating conditions meet specific conditions, so even if a user complains of a malfunction, the same problem cannot be detected while the engine is actually operating. Unless the conditions are reproduced, the failure cannot be discovered. Therefore, in the conventional EEC, when a failure occurs, it is difficult to accurately diagnose it, and locating the failure location requires a high degree of skill and a lot of time. Therefore, as disclosed in, for example, Japanese Patent Application Laid-open No. 55-56202, an apparatus has been proposed in which a predetermined inspection program is executed as necessary.
Furthermore, the operation of the various sensors and actuators of the EEC mentioned above is constantly monitored and an alarm is issued when a failure is detected, and a memory means is provided so that the stored data does not disappear even when the operation of the EEC is stopped. Fault location self-diagnosis for EEC that allows you to immediately know if a failure occurs in various sensors or actuators, and also allows you to immediately know the location of the failure even after the engine has stopped. An alarm device has been proposed, an example of which will be described below with reference to FIGS. 7 to 25 of the drawings. In this example as well, most of the configuration as an EEC is the same as the conventional example shown in FIGS. 1 to 6, so only the different points will be explained in detail in the following explanation. FIG. 7 shows a conventional example of a control system in which a failure location self-diagnosis alarm display device is applied to EEC.The difference from the conventional example shown in FIG. It is equipped with a RAM 1104 that is packed up and configured to operate as a non-volatile memory, and is equipped with an alarm lamp 1106 and a display switch (hereinafter referred to as DISP-SW) 1108. And CPU102, ROM104, RAM1
By a microcomputer program such as 06,
Checking inputs from various sensors 132 to 148, including the air flow rate sensor 24, water temperature sensor 56, etc., and inputs from various switches, such as the idle switch 148 to the start switch 152, under predetermined timing and conditions, respectively; The outputs of various actuators such as the injector 12, fuel pump 32, and bypass valve 61, as well as the amplifier 62 and transistor 90 included therein, are checked, and if any abnormality is found in these inputs or outputs, As shown in Figure 8, coded data corresponding to these abnormalities (hereinafter simply referred to as malfunction codes) is
It is written in the RAM 1104 and displayed on the alarm lamp 1106 as necessary. Therefore, if the above-mentioned abnormality occurs while driving the car or when starting the engine, the abnormality is immediately displayed on the alarm lamp 1106, and the driver of the car can continue driving without knowing that a malfunction has occurred. You can prevent it from continuing. The lighting mode of the warning lamp 1106 at this time is, for example, as shown in Fig. 9 a and b.
indicate cases in which an abnormality has already been detected before starting. As is clear from FIG. 9a, the lamp lights up when the key switch is turned on, and then goes out when the engine starts. This makes it possible to check that there is no abnormality in the alarm lamp 1106 itself. The lamp remains off as long as no abnormality occurs. Next, when a malfunction occurs, the light goes into a flashing mode that lights up for 0.6 seconds at 0.6 second intervals.
The light will continue to blink until the problem is resolved, and if the problem is resolved for some reason, it will remain off. At this time, if the engine stalls, the light will remain on as it does from the time the key switch is turned on until the engine starts. Also, as is clear from Figure b, if an abnormality occurs immediately when the key switch is turned on, or if an abnormality has already been detected before that, the flashing mode is set from the beginning and the alarm lamp 11 is turned on.
06 continues flashing. Also, even if the engine stalls at this time, the flashing mode will not change this time. Therefore, simply by seeing the flashing warning lamp 1106, one can know that some kind of abnormality has occurred and further continuation of operation is no longer desirable. Next, when the display switch 1108 is operated, an input is given to the CPU 102 via the DIO 128, the operation mode of this control circuit becomes a failure mode display mode, and the program is switched. When you enter this display mode program, the ROM
The code is read from 1104, and the alarm lamp 110 is turned on according to the read code.
Since the lighting mode of 6 is controlled, a person who inspects or repairs a car, such as a service operator, can simply read the code from the flashing mode of this warning lamp 1106 to detect abnormalities in various sensors, actuators, etc. Since it is possible to identify the object and also know the nature of the abnormality at the same time, inspections and repairs can be carried out easily and accurately in a short period of time. The lighting mode of the alarm lamp 1106 at this time is, for example, as shown in FIGS. 10 a to 10 c. First, a shows the alarm lamp 110 when the display mode is set by operating the display switch 1108 and no malfunction has occurred up to that point.
6 lighting mode, the code at this time is [01] as shown in Figure 8, so after 2.4 seconds of preparation time has elapsed after the display starts, the code at this time is 0.3.
Repeat lighting for 3 seconds and turning off for 3 seconds 3 times. This state is maintained as long as the display switch 1108 is turned on. Next, when b is in display mode, by then
If an error occurs in which the ISC terminal shorts, and as a result, code [22] is stored in RAM 1104, after 2.4 seconds of preparation time,
1.2 seconds of lighting time with 0.6 seconds of turning off time 2
Then, the blinking state, which occurs when the lighting time of 0.3 seconds continues twice, is repeated three times each. As is clear from these Figures 10a and b,
The number of flashes for 1.2 seconds following the 2.4 seconds of preparation time represents the 10s digit of the code, and the number of flashes for 0.3 seconds represents the 1s digit of the code.
It can be seen that the 3 seconds of lights-out time represents a code break. Therefore, in Figure 10a, the code is [01], so it lights up for 0.3 seconds once, and in Figure 10b, the code is [22], so it lights up twice for 1.2 seconds.
The lights appeared twice for 0.3 seconds each. In this way, display switch 110
Warning lamp 1106 that occurs when 8 is turned on
The code previously stored in the RAM 1104 can be visually read very easily depending on the lighting state of the code, and the location of the abnormality can be easily identified and the contents of the abnormality can be easily known. By the way, since such an EEC is equipped with a large number of sensors and actuators, there is a considerable possibility that a plurality of malfunctions may occur at the same time or in a relatively short period of time. Therefore, in this conventional example, a plurality of addresses are provided in the RAM 1104, so that a plurality of fault codes, for example three, can be stored. Therefore, in such a case, when the display switch 1108 is turned on and switched to the fault code display mode, the plurality of fault codes that have been stored up to that time are sequentially displayed three times each as shown in Figure 10c. It is now displayed. In other words, if the currently memorized fault codes were [22] and [15], code [22] would be displayed three times, followed by code [15] three times, and this would cause switch 1108 to be displayed. This will repeat until you turn it off. Therefore, even if a plurality of abnormalities have occurred up to that point, up to three abnormalities are stored and displayed in sequence, making it extremely easy to discover the malfunction. In addition, even if there is no problem,
The purpose of storing the code [01] in the RAM 1104 and reading it out and displaying it during the display mode is to confirm that no abnormality has occurred in the system including the RAM 1104. It can be done reliably. In this manner, according to the above conventional example, when an abnormality occurs during engine operation, the abnormality occurs in the battery 110.
2, the code is stored in the RAM 1104, which operates as a non-volatile memory, so that the location and contents of the problem can always be clearly known even after the engine has been stopped. Next, operations in the alarm bubble mode and code display mode when malfunctions of the various sensors and actuators shown in FIG. 8 are detected will be described. Figure 11 is a flowchart showing the operation for identifying alarm mode and code display mode, which is incorporated into the level 2 task in the program system diagram shown in Figure 5, and is activated every 40 [mSEC]. ing. When entering this task, it is determined in step (hereinafter referred to as S) 1 whether the display switch 1108 is ON or not, and if NO, the process advances to S2.
The RAM 1104 is checked to see if there is a defective flag, and if NO, the process directly proceeds to EXIT.
When the result in S2 is YES, the alarm operation in S3 is performed. Also, if the result is YES in S1, move on to S4,
Performs code display operation. Figure 12 is a flowchart showing the details of alarm operation S3 in Figure 11.
In S31, it is determined based on the flag whether or not the time setting is completed. If the result in S31 is NO, the process advances to S32 to set the flag. This is for checking the completion of the time setting required in S31. Then in S33
Set the time to 0.6 seconds. This time setting is performed by setting an initial value to a counter. Finally, in S34, the state of the alarm lamp 1106 is reversed, and then the process goes to EXIT. Also, when the result in S31 becomes YES,
Proceed to S35 and determine whether 0.6 seconds have elapsed by looking at the counter set in S33. If the result is NO, subtract 1 from the time counter in S37 and proceed to EXIT. Furthermore, if the result in S35 is YES, the flag is reset in S38 and then the process proceeds to EXIT. Therefore, the next time this flow is entered, the process will proceed from S31 to S32. The result of implementing the above flow is as follows. First, the first thing that comes into this flow is
As is clear from FIG. 11, this is when an abnormality occurs and the defect flag is raised in a state where there was no defect flag until then. Therefore, when entering S34 from S31 through S32 and S33, the warning lamp 1106 is still on.
is not lit. Therefore, in S34, lamp 110
6 lighting is performed. and then 40
When entering this flow every [mSEC], the time counter is sequentially decremented in S36, and when 0.6 seconds have passed, it becomes 0, so the flag is reset in S38. So next time I go from S31 to S34 again, but this time the lamp is on, so
This time, the lamp 1106 is turned off. Accordingly, the alarm operations shown in FIGS. 9a and 9b are performed by the flow shown in FIG. 12. It should be noted that the time counters referred to as S33, S35, S36, etc. are configured by software in the program of the CPU 102 using the memory area of the RAM 106 (Fig. 7), and it is clear from the above explanation. Thus, the initial value to be set in S33 is 0.6 seconds divided by 40 [mSEC], that is, 150. Next, FIGS. 13 to 15 are flowcharts showing details of the code display operation S4 in FIG.
When entering this flow, first check the flag in S301 to determine whether the 2.4 second timer is set, and if NO, proceed to S302 and turn on the alarm lamp.
106 is turned off, a 2.4 second timer is set, and a flag is set. Next, turn to S303 and check the flag to see if 2.4 seconds have passed.If the result of S301 is YES, skip S302.
Proceed to S303. If the result here is NO, S304
Turn to , then subtract 1 from the 2.4 second tire. Next, in S305, check whether the 2.4 second timer has reached 0 or not, and if NO, exit from EXIT, but if YES, exit from EXIT.
Set the flag in S306. By executing these steps S301 to S306, the light-off time of 2.4 seconds from the start of the display shown in FIGS. 10a and 10b is set. Note that the timer referred to here is the same as the time counter described above, and is configured in software. After this, the code is displayed in the manner shown in FIGS. 10a to 10c, but this point is not particularly relevant to the gist of the present invention, and if you look at the flowcharts in FIGS. 13 to 15, Since it is easy to understand, detailed explanation will be omitted. Next, the abnormality detection operations of the various sensors and actuators described above will be explained. In the embodiment of the present invention, when detecting an abnormality in a sensor, etc., the determination of whether or not there is an abnormality is repeated multiple times, for example, five times. In order to eliminate detection results that result in an abnormal state and reliably detect only abnormalities in the true sense,
The operations shown in the flowchart in the figure are performed. That is, when an abnormality detection program for various sensors, etc. is entered under predetermined conditions or timing, the operation shown in FIG. 16 is performed, and first, in S601, it is determined whether or not there is an abnormality. Note that the determination operation in S601 corresponds to various types of sensors and actuators, and some examples will be described later. If the determination result in S601 is NG, that is, abnormal, the process advances to S602 and the NG counter is incremented. This NG counter is for counting the number of judgments. Next, the process goes to S603 to check whether the content of this NG counter is 5 or not.
By the way, if the result in S601 is NG for the first time, the result in S603 will naturally be NO, so proceed directly to EXIT and end this operation. Next, when entering the operation of this flow, S601
If the result becomes NG again, the above operation is repeated, and the NG counter is incremented by 1 each time in S602. Therefore, if the operation of this flow is started and the result in S601 is NG each time,
In other words, during that time, the abnormal condition continues and it is 5
The result in S603 becomes YES only when the abnormality is detected several times. In this case, the process proceeds to S604 to set the contents of the NG counter to 0, and then sets the defect flag indicating that an abnormality has been detected in S605. Then, in S606, NG processing is performed such as storing a code corresponding to the content of the abnormality at a predetermined address in the RAM 1104 according to FIG. 8, and the flow exits. Also, if the result in S601 is OK, that is, there is no abnormality, the process proceeds to S607, and the contents of the NG counter are checked. If it has not reached 0, that is, the result is NO, the process proceeds to S608, and the contents of the NG counter are checked. After setting it to 0, head to S608. On the other hand, if the result in S607 becomes YES, proceed directly to S609, check whether or not the defective flag is set, and if the result is YES, clear the defective flag through S610, exit to EXIT, and return to NO. Sometimes S609
Exit immediately to EXIT. As a result of performing the operation according to the flowchart in FIG. 16, each time the judgment result in S601 becomes OK, that is, there is no abnormality, the NG counter is reset to 0 and the defective flag is cleared in S607 to S610. Therefore, the judgment result in S601 is 5 times,
The failure flag is set through S605 only when the result is NG continuously, that is, there is an abnormality, and it is possible to eliminate abnormalities caused by false detection of temporary abnormalities due to noise or the like. Note that if the content of the NG counter in S603 is set to another number, the number of times the check is performed can be set to an arbitrary number accordingly. In addition, in this embodiment, after the failure flag has been set and NG processing has been performed five times in a row,
Even if the result in S601 is OK, the defect flag is set and NG processing is performed again only when NG occurs five times in a row.However, once the defect flag is set, NG processing is performed again. It can be considered that the reason why the judgment becomes OK after the test is carried out is more likely to be due to an error being determined as normal than if the abnormality disappears.
If the determination becomes NG after that, the defect flag may be reset and NG processing may be performed immediately. In other words, in this case, even if the result in S601 is not NG five times in a row, S602 is immediately executed just once.
Then, it passes through S605. To this end, for example, a step may be provided after S610 to set the contents of the NG counter to 4. Next, the abnormality check of various sensors and actuators shown in S601 of FIG. 16 will be explained. First, an embodiment of the abnormality check operation of the air flow sensor AFS will be described with reference to the flowchart of FIG. This operation is processed as one task of the level 2 task 256 in Fig. 5. When entering this flow, data from the AFS 24 (Fig. 7) is first fetched from the RAM 106 in S901, and then the data is judged in S902. Do this. As shown in Fig. 18, this AFS24 generates an output voltage within the range under normal conditions, so when it is determined in S902 that the data is within the range, the determination result is unchanged.
OK. However, when the result in S902 is determined to be a low output state, the process proceeds to S903, prepares to set a defective flag corresponding to the low output, and exits with a determination result of NG. Therefore, at this time, the code "14" is stored according to FIG. Also, when the result of S902 is judged to be a state of high output, it turns to S904, checks whether the engine speed is 4000 rpm or more, and confirms the result.
If it says YES, you can exit OK. On the other hand, the result is NO
If so, the process advances to S905, prepares to set a failure flag corresponding to the large output, and then exits to NG. Therefore, at this time, as shown in Figure 8,
Code "15" is memorized. In addition, here S904
The reason why this is provided is that even if the AF data reaches the high output range, it is not abnormal when the engine speed is high. Next, FIG. 19 shows an embodiment of an abnormality check system for the actuator that controls the idle speed, that is, the bypass valve 61. In the figure, 210 and 211 are detection signals PA6
and the output terminal of PA7, 212 is the input terminal of test signal PB7, Q213 is the amplification transistor, Q2
14 is a driving transistor, and Q215 is a detection transistor. FIG. 20 is a flowchart showing the abnormality check operation, in which background job 208 (fifth
This is executed as one program shown in FIG. 2. When this flow starts, first, in S20, the detection signals PA6 and PA7 are read, and then in S21, it is checked whether the signal PA6 is 0 or 1. Then, when the result becomes 1, the signal is sent in the following S22.
Check whether PA7 is 0 or 1, and if the result is 1, it is assumed that there is no abnormality and exits successfully. In other words, signal PA6
is 0, which means that the signal ISC is 1, so it is normal for both transistors Q213 and Q214 to be on, and therefore transistor Q21 is turned on.
5 should be off, so at this time the signal
If PA7 is also 1, it means that there is no abnormality. Also, if the result in S22 becomes 0, this indicates that one or both of transistors Q213 and Q214 is in the oven state, so S23
Proceed to prepare to set the bad flag, then
Passed out in NG. Therefore, at this time, the code "20" will be stored according to FIG. On the other hand, if the result in S21 becomes 0, proceed to S24, check the signal PA7, and if it becomes 0, proceed to S24.
Proceed to OK. In other words, if signal PA6 becomes 0, signal ISC
However, transistors Q213 and Q214 are off, and transistor Q215 is therefore on. Therefore, if signal PA7 is also 0, it is in a normal state. However, if the result in S24 becomes 1, the next 725
After setting the test signal PB7 of the terminal 212 to 1, the signal PA7 is read in S26, and it is checked whether this signal PA7 is 1 or 0 in the following S27. When the result becomes 1, preparations are made to set the output shot defect flag at S28, and then the process exits to NG. Therefore, the code "22" will be stored at this time. Also, if the result in S27 is 0, turn to S29,
The harness oven defect flag is set and the error is NG, and the code "21" is stored. In other words, if signal PA6 is 0, transistor Q2
13 and Q214 are supposed to be off and transistor Q215 is supposed to be on, so signal PA7 must be 0. However, signal PA7 becomes 1, which means that the base of transistor Q215 becomes 0.
It means becoming. Therefore, signal at S25
When setting PB7 to 1, if signal PA7 does not become 0, a signal is sent to the base of transistor Q215.
Since this means that PB7 is not given, it can be seen that the output is shot. Also, if the signal PA7 becomes 0 at this time, it means that the signal PB7 is applied to the base of the transistor Q215,
Therefore, it means that no voltage has been applied from the power supply +B through the solenoid valve 61 until then, and it is determined that the harness is open. Next, FIG. 21 shows an example of an abnormality check system for the pressure control valve 84, which is an actuator for EGR control, in which 901 and 903 are output terminals for detection signals PA4 and PA5, 902 is an input terminal for test signal PB5,
Q91 and Q92 are detection transistors.
Note that 90 is a transistor for driving the pressure control valve 84. FIG. 22 is a flowchart showing the operation of this abnormality check system, which operates as one of the programs of background job 208 in FIG. When entering this flow, first the S40 detection signal PA
4. Read PA5, then signal PA4 becomes 1 in S41
or 0. If the result in S41 is 0, the process advances to S42 to check whether the signal PA5 is 1 or 0, and if the result is 1, the process exits to OK. Further, when the result is 0, a defect flag is prepared to indicate that the transistor 90 has been opened through S41,
Passed out in NG. In other words, signal PA4 is 0 in S41.
This indicates that the transistor Q91 is on, that is, the signal EGR is 1, and at this time, the transistor 90 should also be on.
Therefore, if transistor 90 is normal, transistor Q92 will be turned off, so if the result is 1 when PA5 is checked in S42, there is no abnormality and it is OK.
If the result is 0, the transistor 90 is in an oven abnormality and becomes NG. Therefore, at this time, the code "23" is entered from Figure 8.
is memorized. Also, if the result in S41 is 1, proceed to S44,
Check signal PA5 and if it is 0 then OK
However, if the result becomes 1, proceed to S45 and first try setting test signal PB5 to 1. Then S46
After reading the detection signal PA5 in S47, it is checked whether it is 0 or 1. If the result in S47 is 1, S48
The output ground failure flag is prepared through S49, and when the result becomes 0, the harness open failure flag is prepared in S49, and each exit is NG. In other words, the signal PA4 becoming 1 in S41 means that the input signal EGR is 0.
Therefore, if the transistor 90 is normal, it should be off, and at that time the transistor Q92 is on, so if the detection signal PA5 is 0 in S44, it is OK. Further, if the result is 1 in S44, it means that the voltage from the power supply +B is not applied to the base of the transistor Q92, so try applying the test signal PB5 in S45. If transistor Q92 still does not turn on, that is, S47
When the result becomes 1, the transistor 90
If the short or output terminal of transistor Q92 is turned on and the result at S47 becomes 0, it can be seen that the path from the power supply +B to the base of transistor Q92 is defective in the oven, that is, the harness oven. Therefore, when passing through S48, the code is "25"
However, when the code passes through S49, the code "24" is stored. Next, an embodiment of the abnormality check system for the fuel pump 32 is shown in FIGS. 23 to 25. FIG. 23 shows a circuit of a relay driving transistor Q32 of the fuel pump 32, and a detection signal PA2 is taken out from its collector. By the way, there are two types of abnormality checks for the fuel pump 32: one in normal operating conditions and one when the engine stalls. First, Fig. 24 shows the one during normal operation, and is checked every 10 minutes, for example, by a timer interrupt. First, in S60, the control signal IDO0 is set to 1 to turn off the transistor Q32. This is because under normal operating conditions, the fuel pump 32 is in operation and therefore the control signal is
This is because DIO0 is set to 0. Then, after a predetermined waiting time, it is checked in S61 whether the detection signal PA2 has become 0 or not. If the result is determined to be YES, the signal DIO0 is set to 0 in S62.
I set it back to , and it exits OK. Further, if the result in S61 is NO, the process proceeds to S63, where a defect flag indicating that the transistor Q32 has become defective in shot is prepared, and the process exits to NG. In other words, if transistor Q32 is normal, it is turned on and off by control signal DIO0, and detection signal PA2
is 1 if transistor Q32 is on, and 0 if it is off.
This is because it is supposed to be. Therefore, at this time, code "33" is stored. Next, FIG. 25 shows the operation when the engine stalls, which is performed by one program of the engine stall task 262 (FIG. 5). When entering this flow, first S72
The detection signal PA2 is checked and it is determined whether it is 0 or not. If the result is YES, the process advances to S71, where the output terminal short failure flag including the F/P relay is prepared, and the process exits to NG. In other words, since the signal DIO0 is still 0 at this time, the transistor Q32 should be on, and if the signal PA2 is 0 despite this, it is determined that the output terminal is short. Therefore, at this time, code "34" will be stored. Also, if the result in S70 is NO, the next S72
First, signal DIO0 is set to 1 to turn off transistor Q32, and then signal PA is turned off again in S73.
Examine 2 and then determine whether it becomes 1 or not. If the result in S37 is NO, it exits as is, but if it is YES, the harness leading to the fuel pump 32 prepares a flag for an open failure in S74, and exits as NG. That is, at this time, even though the transistor Q32 is turned off, the voltage from the power supply +B appears as the signal PA2, which means that the output harness is open. Therefore, at this time, code "35" will be stored. In addition, the abnormality check when the engine stalls is 1.
Don't do it repeatedly. Therefore, steps other than S605 and S606 in the flow of FIG. 16 are omitted. By the way, in such a system, in order to detect an abnormality in the ignition system, it is necessary to perform the detection in accordance with the timing of the operation of the ignition system. In other words, in order to detect an abnormality in the ignition system, it is necessary to turn the drive transistor and power transistor 64 ON/OFF, so in order to detect an abnormality without affecting the operating state of the engine, As mentioned above, you need to take the timing. Therefore, in the past, the abnormality detection operation became complicated due to the above-mentioned timing adjustment, and moreover, it was difficult to perform the abnormality detection operation with sufficient accuracy. SUMMARY OF THE INVENTION An object of the present invention is to provide a self-diagnosis device for an ignition system which eliminates the drawbacks of the prior art described above, has a simple configuration, and is capable of reliably detecting an abnormality in the ignition system. In order to achieve this object, the present invention is characterized in that the occurrence of engine stall (hereinafter referred to as engine stall) is monitored, and the ignition system is diagnosed only when the engine stalls. DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a self-diagnosis device for an ignition system according to the present invention will be described below with reference to the drawings. FIG. 26 shows an embodiment of a circuit for self-diagnosis according to the present invention, which is provided in the amplifier 62 of FIG. 2, in which Q621 is an input transistor, Q622 is a driving transistor, and Q623 is a test transistor. . As already explained, 58 is an ignition coil, and 64 is a power transistor. Also, IGN is the ignition pulse, S is the diagnostic signal,
M is a monitor voltage. FIG. 27 is a flowchart showing an example of the self-diagnosis operation of the ignition system using this circuit, and the operation will be explained below using this diagram. This diagnostic operation is processed, for example, as one of the level 2 task 256 or the level 3 task 258 in FIG. Check whether it is familiar or not, and if it is NO
When , the process immediately exits to EXIT and no processing is performed in this flow. Note that the engine stall flag at this time is set to a predetermined address in the RAM 106, for example, by processing by the engine stall task 262. On the other hand, if the result in S80 is YES, that is, the engine stall flag is set, the process advances to S81.
While outputting the diagnostic signal S to the transistor Q623, the collector voltage of the driving transistor Q622, that is, the monitor voltage M is read. At this time, the ignition pulse IGN is set to the engine stall task 262.
Since it is reset by (see Table 1),
The driving transistor Q622 is in the on state,
It turns off only after the signal S is applied. Next, the process advances from S81 to S82, and in this step it is checked whether the monitor voltage is smaller than 0.6V.
And when the result is YES, it turns to S83 and this
The defect flag is set in S83, and the RAM is set in S84.
After memorizing the fault code "36" in 1104
Exit to EXIT and end the processing according to this flow.
On the other hand, if the result in S82 is NO, that is, the collector voltage of the driving transistor Q622 is greater than 0.6V, the process proceeds to S85, where it is checked whether the monitor voltage M is greater than 3V. If the result is YES, proceed to S86,
At this step 86, the defect flag is set, and the following S
After memorizing the fault code "37" in 87
Exit to EXIT and end the processing according to this flow. Also, if the result in S85 is NO, the next S
Proceeding to 88, the monitor voltage M is read after the diagnostic signal S is set to zero. Next, proceed to S89, where the read monitor voltage M is
It is checked to see if it is greater than 1.3V, and if the result is YES, exits to EXIT through S90 and S91, and the defect flag is set and the defect code "38" is stored, but if the result in S89 is NO. If , the program passes through S92, resets the defective flag, and then exits to EXIT. Next, the results obtained by performing the operations according to the flowchart of FIG. 27 will be described with reference to FIG. 28. 1 in FIG. 28 represents the signal REF from the crank angle sensor 146, and this REF disappears when the engine stalls. Then, it is determined that an engine stall has occurred only when REF does not appear for one second. Therefore, at time _T0 in FIG. 1, ENST IRQ is generated and an ENST flag is set at a predetermined address in RAM 106 as shown in FIG. On the other hand, since the ignition pulse IGN is generated by the signal RER as shown in Figure 28 2, when the engine stalls and REF disappears, IGN stops changing.
When an engine stall occurs at the timing indicated by the solid line arrow in Fig. 1, the result is as shown by the solid line in Fig. 2, but when the engine stall occurs at the timing indicated by the broken line arrow in Fig. 1, the result is as shown by the broken line in Fig. 2. It becomes like this. At this time, the engine stall task 26
2 makes the ignition pulse IGN zero. As a result of the above, the result in S80 becomes YES at the 27th time after time T ₀ in Figures 1 to 3.
This only happens when you enter the flow shown in the diagram. Now, in S81, first, as shown in FIG. 28, at time _T1, a diagnostic signal S is supplied to transistor Q623 to turn on this transistor, thereby turning off transistor Q622. The application time of the signal S at this time is, for example, about 30 msec. Next, the monitor voltage M is read at time _T2 within the period in which 30 msec has not yet elapsed. Since this monitor voltage M changes as shown in FIG. 2 when the ignition system is normal, S81
The results of judging the monitor voltage M read in S82 and S85 should both be NO, but the power transistor 64 is shot, or the wire harness leading to the power transistor 64 is grounded. When this happens, the monitor voltage M changes as shown in Fig. 18, so
When the result in S82 is YES, S83 and S84
The fault code "36" will be stored through the system. Also, when the wire harness leading to the power transistor 64 is in an oven state, the monitor voltage M becomes as shown in Fig. 28, so the result at S82 is NO, but the result at S85 is YES. , the fault code "37" will be stored through S86 and S87. Next, when the results in both S82 and S85 are NO, proceed to S88, and return the diagnostic signal S to zero at time T3, approximately 30 msec after time _T1 , as shown in Fig. ₂₈ . , the monitor voltage M is read at subsequent time _T4 , and checked in S89. At this time,
If the drive transistor Q622 was in the oven state, the monitor voltage M would be as shown in Figure 28, 9, so the result at S89 would be YES, and the fault code "38" would be sent through S90 and S91. It will be remembered. On the other hand, as mentioned above, when the ignition system is normal, the monitor voltage M is as shown in Figure 28 6, so the result in S89 is NO, and this is the first time that there is no abnormality in the ignition system. As a result, the defect flag is reset through S92, and as a result, defect codes "36", "37",
None of the numbers ``38'' will be remembered. Therefore, according to this embodiment, the self-diagnosis operation of the ignition system can be performed independently of the ignition timing, and the diagnostic operation can be performed easily and reliably. By the way, in the above embodiment, the RAM
A battery 1102 is provided for backing up the battery 1104, but this battery 1102 may be one that directly supplies voltage from an automobile battery without going through a key switch, or a separate dry battery or the like may be provided. . Of course, if the RAM 1104 is a nonvolatile memory, these are unnecessary. In addition, a warning lamp 110 is used to display the malfunction code.
6 may be omitted, and another display means, for example, a means capable of directly displaying numbers, characters, etc., may be provided, or if necessary, a fault code may be displayed by connecting with a plug or the like. In this case, the contents of the RAM 1104 can be displayed as they are in numbers or characters. As explained above, according to the present invention, since the abnormality diagnosis operation of the engine ignition system is performed when the engine is stalled, the self-diagnosis operation can be performed reliably with a simple configuration, and if an abnormality occurs in the ignition system. It is possible to immediately know what has happened, and it is also extremely easy to identify the abnormality in the ignition system afterwards, so troubleshooting and maintenance can be done easily and in a short period of time, eliminating the shortcomings of the conventional technology. It is possible to provide an ignition system self-diagnosis device that is useful for a fault location self-diagnosis warning display device that can always obtain a safe and reliable engine operating state.

[Brief explanation of drawings]

Figures 1 to 6 are diagrams showing an example of an electronic engine control system applied to a fuel injection type internal combustion engine. Figure 1 is a cross-sectional view of the engine including a part of the control system, and Figure 2 Figure 3 is a schematic diagram of the ignition system, Figure 3 is a system diagram of the exhaust gas recirculation system, Figure 4 is a system diagram of the exhaust gas recirculation system,
Figure 5 is a block diagram of the overall configuration of the control system, Figure 5 is a diagram of its program system, Figure 6 is a configuration diagram of memory showing program contents, and Figure 7 is a block diagram of the overall configuration showing an example of a fault location self-diagnosis alarm display device. Figure 8 is an explanatory diagram showing an example of a malfunction code, Figures 9 a and b are explanatory diagrams showing an example of the lamp lighting mode during alarm activation, and Figures 10 a to c
11 is an explanatory diagram showing an example of a lamp lighting mode during code display operation, FIG. 11 is a flowchart showing an example of a method for distinguishing between alarm operation and code display operation, and FIG. 12 is a flow chart showing an example of alarm operation. , FIGS. 13 to 15 are flowcharts showing an example of the code display operation, FIG. 16 is a flowchart showing an example of the abnormality check base pattern, and FIG. 17 is a flowchart showing an example of the abnormality check operation of the air flow sensor. Figure 18 is an explanatory diagram of the operation of the air flow sensor, Figure 19 is a circuit diagram showing an example of a bypass valve abnormality check system, Figure 20 is a flowchart to explain its operation, and Figure 21 is an error diagram of the pressure control valve. A circuit diagram showing an example of a check system, FIG. 22 is a flowchart for explaining its operation, FIG. 23 is a circuit diagram showing an example of a fuel pump abnormality check system, and FIGS. 24 and 25 are a flow chart for explaining its operation. FIG. 26 is a circuit diagram showing an embodiment of the self-diagnosis device for an ignition system according to the present invention, FIG. 27 is a flow chart for explaining its operation, and FIG. 28 is a time chart for explaining its operation. be. 58...Ignition coil, 62...Ignition system amplifier, 64...Power transistor, Q621
...Input transistor, Q622...Drive transistor, Q623...Test transistor,
IGN...Ignition pulse, S...Diagnostic signal, M...
...Monitor voltage.

Claims (1)

[Scope of Claims] 1. In an electronic engine control device that controls an engine to a predetermined operating state according to a plurality of data representing the operating state of the engine, there is provided an engine stall detection means that monitors the occurrence of an engine stall, and an ignition system. a first detection means that turns off the driving transistor and detects its collector voltage; a second detection means that turns on the driving transistor and detects its collector voltage; and detection by the first means. a first abnormality determination means that outputs data representing a first abnormal state when the voltage does not reach a first predetermined voltage value; a second abnormality determining means outputting data representing a second abnormal state when the voltage exceeds a third predetermined voltage value; and a third abnormal state because the detected voltage by the second detecting means exceeds a third predetermined voltage value. and third abnormality determining means for outputting data representing the engine stall, and the first and second detecting means and the first to third abnormality determining means are operated when the engine stall detecting means detects an engine stall. A self-diagnosis device for an ignition system, characterized in that: 2. In claim 1, a memory means capable of retaining stored data even when the operation of the engine control device is stopped, and an alarm means are provided, and data representing the first to third abnormal states is outputted. 1. A self-diagnosis device for an ignition system, characterized in that, when the alarm occurs, these data are stored in the memory means, and the alarm means is operated in accordance with the generation of the data. 3. In claim 2, means is provided for sequentially and repeatedly reading data stored in the memory means, and the abnormal state is identified by operating the alarm means in a mode corresponding to the read data. A self-diagnosis device for an ignition system, characterized in that it is configured to enable the self-diagnosis of an ignition system.