JPS62177429A - Trouble diagnosing device for engine - Google Patents

Abstract

PURPOSE:To prevent making an erroneous diagnosis of engine trouble at the time of the next diagnosis by erasing a diagnosed result of the trouble automatically from a memory at the time of attaining the prescribed operational progress. CONSTITUTION:Respective signals S1-S6 of from each sensor or actuator are inputted to a micro-processing unit (MPU) 14 of the titled device via an I/O port 15 and the MPU 14 decides existence or nonexistence of abnormality of each system based on the respective signals S1-S6 and stores a decided result in a memory 16. At the same time, plural diodes 17 and 18 are turned on and off and the occurrence of the abnormality is displayed and it is known on which systems the abnormality occurs. Further, the number of times of changeover is counted and stored in the memory 16 every time an ignition switch 12 or a starter switch 13 is changed over from off to on. Then, when the number of times of storage count of the memory 16 attains the prescribed number of times, the decided result of the abnormality stored in the memory 16 and the number of times of count are erased. In this way, the erroneous diagnosis in case of the next diagnosis can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an engine failure diagnosis device, more specifically, an engine failure diagnosis device that erases a failure determination result from a memory after a predetermined period of engine operation. Regarding.

(Prior Art) Generally, after a failure in an engine control system is repaired, it is necessary to erase the failure diagnosis results stored in memory.

For this reason, examples of methods for erasing failure diagnosis results from memory include the following.

(1) One is to remove the engine control unit power supply for a certain period of time, cut off the current supply to the memory IJ (RAM) in the control unit that stores the failure diagnosis results, and erase the diagnosis results from the memory. (Refer to "Toyota Soarer New Model Manual" published by Toyota Motor Corporation, February 10, 1981).

(2) Another method is to provide a memory erasing switch in the engine control unit, and by operating the switch, the failure diagnosis results stored in the memory of the control unit are erased.

(Problem to be solved by this invention) However,
In the conventional memory erasing method of erasing the diagnostic results of a failure from the memory, the diagnostic results will be erased unless some operation is performed, such as removing the power to the control unit or operating the switch for erasing the memory of the diagnostic results. Because it was not possible to delete the diagnosis result from the memory, once it was determined that a failure had occurred, the determination result continued to be stored in the memory until the diagnosis result was erased from the memory. That is, if a fault diagnosis reveals that a system is abnormal, the system can be restored to normal condition by repairing the system. However, in this case, unless the diagnostic results are erased from the memory that stores the diagnostic results, the system that has been returned to a normal state through repair will continue to be diagnosed as faulty. For this reason, there is a problem in that the next time a failure diagnosis is performed, a normal system is mistakenly determined to be abnormal. In addition, if it is determined that there is an abnormality due to an accidental contact failure with a connector, etc.,
After that, even if no contact failure occurs and the system is normal, the diagnosis result that the system is abnormal will continue to be stored.

(Means for Solving the Problems) The present invention has been made to solve these problems, and its basic conceptual diagram is shown in FIG.

That is, the present invention includes a failure determination means a for determining whether or not there is a failure in the control system based on each signal from the engine control system, and a storage means for storing the determination result of the failure.
Measuring means C for measuring the operating progress of the engine after determining the failure
and erasing means d for erasing the stored failure determination result from the storage means when a predetermined operating progress is reached.

(Function) In the present invention having such a configuration, when a predetermined operating progress is reached, the stored failure determination result is automatically deleted from the recording means, so a special operation is not required for deletion. There is no need to do this.

Furthermore, unlike in the past, when the system returns to normal, the determination result is not left in the storage means as it is still diagnosed as a failure, so there is no possibility of erroneously determining normality as abnormality during the next failure diagnosis.

Further, when a contact failure that occurs accidentally returns to normal after that, the previous abnormality determination will not remain as it is. Furthermore, since frequently occurring failures are continually updated and stored in memory, only the necessary parts need to be repaired during maintenance inspections, thereby reducing waste.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIGS. 2 and 3 are diagrams showing one embodiment of the present invention.

First, to explain the configuration, in FIG. 2, l indicates an engine body, and an intake pipe 2 is connected to this engine body l. A throttle valve 4 for controlling the amount of intake air is disposed in the middle of an intake passage 3 formed in the intake pipe 2.
An air flow meter 5 is interposed on the upstream side of the throttle valve 4. The flow rate of intake air is detected by an air flow meter 5, and an output signal S1 of the air flow meter 5 is input to a control unit 6. Further, the cooling water temperature of the engine body 1 is detected by a water temperature sensor 7, and the vibration due to combustion in the engine body 1 is detected by a knock sensor 8.
Output signals S2 and S2 from the water temperature sensor 7 and the knock sensor 8 are input to the control unit 6, respectively. A distributor 9 is disposed near the engine body 1, and a crank angle sensor is built into the distributor 9. The crank angle sensor is
For example, the unit angle of the crank angle is detected, each cylinder is discriminated, and each output signal S, , S, is sent to the control unit 6, respectively. An ignition plug IO is attached to each cylinder of the engine body 1, and a high-pressure pulse is supplied to the ignition plug 10 from an igniter 11 having an ignition coil. An output signal S6 is input from the igniter 11 to the control unit 6 for determining whether or not an ignition signal is being output. Further, 12 indicates an ignition key switch, and 13 indicates a starter switch.
N, OFF signal S1, Sll is control unit 6
are entered into each.

The control unit 6 is composed of an example microprocessing unit (MPU) 14, an I10 board 15, and a memory 16, and has functions as a failure determination means, a storage means, a measurement means, and an erasing means. . In other words, in order to perform failure diagnosis, the MPU 14 has
Each sensor or actuator signal 81 to S6
is input via I10 boat 15, and MPU1
4 determines whether or not there is an abnormality in each system (including sensors or actuators and their associated wiring systems) based on the signals SI to S6. That is, MPU1
4 executes processing for diagnosing abnormalities in each system according to a preset abnormality determination program.

If an abnormality occurs in any system of the MPU 14,
It is determined and the determination result is stored in the memory 16. By blinking a plurality of light emitting diodes 17 and 18 at the same time, the occurrence of an abnormality is warned and displayed.

At this time, it is possible to determine in which system the abnormality has occurred based on the blinking state of these light emitting diodes. Further, each time the ignition key switch 12 or the starter switch 13 is switched from OFF to ON, the number of switching is counted, and this counted number is stored in the memory 16.
It is written and noted within. When the count number tα recorded in the memory 16 reaches a predetermined number, the abnormality determination result 1a recorded in the memory 16 is erased and the count number is also erased. In addition, the light emitting diode 17
．． The blinking of 18 is also stopped.

Next, the effect will be explained.

FIG. 3 is a flowchart showing a program for performing abnormality determination processing, and 5l=SIO in the figure indicates each step.

In addition, this program, for example, every engine rotation,
Or it is executed repeatedly at predetermined time intervals.

First, each signal 81-S input at S.

Based on this, the MPU 14 determines whether there is a failure in each system (whether the NG condition is met). S when the NG condition is met
2, and if not established, proceed to S3.

In S2, the memory MGMEM (diagnosis result storage memory) is set to l (NG condition met), and at the same time, the memory STMEN (memory that counts the number of times the starter switch 13 turns from OFF to ON) is set to 0 because the NG condition is newly met. As such, proceed to S. That is, if it is determined that NG is established again in the same system before the count reaches 50 times, the memory of the number of 0FF-ONs of the starter switch 13 is cleared, and the counting of the number of 0FF-ONs is started again from this point. . As a result, abnormal failures that occur frequently (at least once every 50 starts) are always stored in the memory. When the NG condition is established, the diagnosis result is stored in the memory 16, and at the same time, the light emitting diodes 17 and 18 are blinked to issue an alarm. In this case, it is possible to determine in which system a failure has occurred based on the blinking states of the plurality of light emitting diodes 17 and 18.

This allows the failure to be repaired quickly.

In S3, it is determined whether the memory NC; MEM is 1 or not. When it is 0 (when the NG condition is not satisfied), the process returns, and when it is 1, the process advances to S4. In S4, it is determined whether the starter switch 13 is ON or not. If it is not ON, the flag FSTON (a flag that remembers that the starter switch 13 is 0FF-ON) is cleared in S5, and if it is ON, it is cleared in S6. It is determined whether the flag FSTON is 1 or not. Flag FSTON is 1 in S6
When the starter switch 13 is switched from OFF to ON for the first time, the flag FSTON is set.
S as 1. Proceed to. Starter switch 13 for Ss
has been switched from OFF to ON, so increment the OFF→ON count and press S.

Proceed to. In S9, starter switch 13 is 0FF-ON.
It is determined whether the number of times exceeds, for example, 50 times. Note that the number of times this count is not necessarily limited to 50 times, but may be a necessary predetermined number of times. If the count is less than 50 times, return, and if it exceeds 50 times, S. Clear the memory NGMEM and erase the diagnostic results.

In this way, in this embodiment, the starter switch 13 can be turned off without any special operation of a switch or the like.
→When the number of ON times reaches a predetermined value, the diagnosis result can be automatically deleted from the memory 16. Therefore, unlike in the past, a system that has become normal after repair remains in a state where it is diagnosed as faulty, and the next time a fault diagnosis is performed, a normal system is incorrectly judged as abnormal. In addition, if an abnormality is determined due to an accidental contact failure with a connector, etc., and the system returns to normal, the previous abnormality diagnosis result will be erased, so the abnormality diagnosis result will be stored. In addition, frequent failures are updated and stored, so you can simply repair the necessary parts.

Next, FIG. 4 is a diagram showing another embodiment of the present invention.

This embodiment uses a signal S from the ignition key switch 12 instead of the signal S8 from the starter switch 13 used in the previous embodiment. therefore,
In this embodiment, when the number of OFF-ON operations of the ignition key switch 12 reaches a predetermined value (for example, 50 times) after the NG condition is established, the fault diagnosis results stored in the memory 16 are erased. The processing procedure of this embodiment is the same as that of the previous embodiment, and only the reference numerals in the figures will be explained below.

FSSO is ignition key switch 12 0N-OF
This is a flag that stores F, and is 1 when it is ON and 0 when it is OFF. FIKON is ignition key switch 1
2 is a flag that remembers that it has changed from OFF to ON, and is cleared when the ignition key switch 12 is OFF. IKMEM is ignition key switch I
2 is a memory that stores the count number of times the switch turns from OFF to ON.

The other configurations and operations are the same as in the previous embodiment.

Note that the above-described failure diagnosis processing is not limited to one diagnosis system, but is actually executed for a plurality of diagnosis systems. The present invention is not limited to erasing the diagnostic results from the memory 16 only when the number of times the starter switch 13 or the ignition key switch 12 is turned from OFF to ON reaches a predetermined value.
It may also be erased when the h switch is turned on.

(Effects) As explained above, according to the present invention, when a predetermined operating progress is reached after a failure has been determined, the failure diagnosis result is automatically deleted from the memory, so a special deletion operation is required. There is no need to do so, and diagnostic results that have been forgotten to be erased will not continue to be erroneously stored in the memory as is the case in the past. Therefore, there will be no error in diagnosing a failure during the next diagnosis, and any accidental abnormality will be eliminated. In addition, frequently occurring failures that occur until a predetermined operating progress is reached are updated and stored in memory, making it possible to repair only the necessary parts during maintenance inspections, eliminating unnecessary part replacements and failures that do not recur over a long period of time. This saves you the waste of having to spend a lot of time researching.

[Brief explanation of drawings]

Fig. 1 is a basic conceptual diagram of the present invention, Figs. 2 and 3 are diagrams showing an embodiment of the invention, Fig. 2 is an overall configuration diagram thereof, and Fig. 3 is a flowchart showing its control program. , FIG. 4 is a flowchart showing another embodiment of the present invention. l...Engine, 5.7-9.11...Control system, 6...
・Control unit < [judgment means, storage means,
measuring means, erasing means), 17.18... Light emitting diode.

Claims (1)

[Claims] A failure determination means for determining the presence or absence of a failure in the control system based on each signal from the engine control system, a storage means for storing the failure determination result, and a measurement means for measuring the operating progress of the engine after determining the failure. What is claimed is: 1. An engine failure diagnosis device comprising: and an erasing means for erasing the stored failure determination result from the storage means when a predetermined operating progress has been reached.