JP2849402B2 - Vehicle failure diagnosis device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION << Industrial application field >> The present invention transmits / receives information by communication with an on-vehicle electrical component control unit such as an engine control unit to diagnose a failure of the on-vehicle electrical component. The present invention relates to a vehicle failure diagnosis device including a tester.

<< Conventional technology >> As for a vehicle failure diagnosis device, for example,
There are known ones such as those disclosed in JP-A-63-135250. In such a failure diagnosis apparatus for a vehicle, a unit for controlling an on-vehicle electrical component that controls an on-vehicle electrical component such as various actuators and sensors to constitute an electronic control system (for example, an engine control unit for electronically controlling an engine). A tester for failure diagnosis, sends test signals such as drive or stop commands for various actuators from the tester side to the control unit side, and displays various operating statuses of the electronic control system for these test signals. A response such as a detection signal of a sensor is returned from the control unit side to the tester side, and the failure of the electronic control system is diagnosed by transmitting and receiving information to and from each other by the two-way communication.

《Problems to be solved by the invention》 However, there are various control units mounted on a vehicle such as an engine control unit and an electronically controlled automatic transmission.
Depending on the type of vehicle, they are standard equipment or optional equipment, so at the time of vehicle maintenance such as periodic inspections, what kind of control unit is currently installed on the vehicle prior to various failure diagnosis by the tester. First of all, it is necessary to list all of them. However, in the related art, there is a problem that each control unit arranged in each part of the vehicle is visually checked and listed, which is troublesome and troublesome, and therefore, maintenance is not good.

In addition, there is a possibility that the electronic control system related to the overlooked control unit will not be diagnosed because it is a list that is visually checked. It is desired to eliminate mistakes.

The present invention has been made in view of the above-described background, and it is possible to reliably and easily perform a list of control units mounted on a vehicle and a confirmation of a current mounting state thereof without oversight. It is an object of the present invention to provide a fault diagnosis device for a vehicle that can be used.

<< Means for Solving the Problems >> The present invention connects a tester that communicates with each of the in-vehicle electrical component control units, and individually performs a failure diagnosis between the tester and each of the control units. In the vehicle failure diagnosis device configured to transmit and receive the information, the tester is provided in the tester, and detects whether or not the tester and each of the control units can communicate with each other at the time of failure diagnosis, and stores the detection result in the tester. A detection unit to be created; and a storage unit provided in any of the control units and storing the detection result detected by the detection unit at the time of previous failure diagnosis as an old detection result so as to be readable by the tester. It is characterized by having.

Further, the storage means is provided in a control unit which is likely to be provided as a standard among the control units.

Further, the tester includes a comparing unit that compares the detection result created in the tester with the old detection result read from the storage unit.

Further, the comparison means generates a warning when the detection result created in the tester is less than the old detection result read from the storage means.

Further, the comparing means, when the detection result created in the tester exceeds the old detection result read from the storage means, converts the old detection result of the storage means to the detection result. It is characterized by updating.

<Operation> With the configuration described above, among the control units, those that can communicate with the tester are detected by the detection unit, and the detection result is stored in the storage unit as the old detection result. When the maintenance unit is completed, the control unit connected thereto is detected by the detection unit using the tester and stored in the storage unit. At the next maintenance, the old detection result is read out from the storage unit at the next maintenance. The control unit mounted and stored before the failure diagnosis can be reliably listed without overlooking. This can improve maintainability and eliminate service errors.

Also, by comparing the old detection result at the time of the previous failure diagnosis with the detection result at the time of the current failure diagnosis by the comparing means, it is possible to easily and reliably grasp the current mounting state of the control unit and the increase / decrease thereof. From this aspect, it is possible to improve the maintainability and eliminate service errors.

Further, by generating a working when the current detection result is less than the old detection result, a control unit that cannot communicate can be easily found.

Also, by updating the storage unit when the current detection result exceeds the old detection result, the latest detection result can be always stored in the storage unit, and this is effective at the next failure diagnosis. Can be used for

<< Embodiment >> An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a perspective view showing a preferred embodiment of a vehicle failure diagnosis device according to the present invention.

In the figure, 1 is a tester for failure diagnosis, and 2 is an engine control unit (hereinafter abbreviated as ECU) exemplified as one control unit.

The tester 1 is connected to the ECU 2 by a communication path 5 via a serial interface 3 and a centralized connector 4, and is capable of transmitting a diagnostic command and receiving various information from the ECU 2, which is a control unit, such as a response thereto. Information is mutually transmitted and received by bidirectional serial communication with the ECU 2.

The ECU 2 is connected to a large number of sensors 6 and actuators 7 arranged at various parts of the engine (not shown). The ECU 6 controls the sensors 6 and the actuators 7 to form an electronic control system. Are controlled.

In addition to the ECU 2, the centralized connector 4 includes control units 20 to 23 for electronic control systems mounted on the vehicle such as an electronic control automatic transmission, an anti-lock brake, an electronic control power steering, and an air conditioner. They are centrally connected via the communication path 5 and are collectively collected. The serial interface 3 connected to the tester 1 is detachably connected to the centralized connector 4.

Basically, the present invention relates to a unit for controlling on-vehicle electrical components.
A vehicle in which a tester 1 for communicating with these devices is connected to 2, 20 to 23, and information for failure diagnosis is individually transmitted and received between the tester 1 and each of the control units 2, 20 to 23. Detecting means provided in the tester 1 for detecting whether or not these control units 2, 20 to 30 can communicate with the tester 1 at the time of fault diagnosis and creating a detection result in the tester 1; The storage unit 8 is provided in any of the control units 2 and 20 to 23 and stores the detection result detected by the detection unit at the time of the previous failure diagnosis as the old detection result in a readable manner by the tester 1.

The tester 1 includes a comparison unit that compares a detection result created therein with an old detection result read from the storage unit 8.

The comparing means, when the detection result created in the tester 1 is less than the old detection result read from the storage means 8,
Generates a warning.

The comparing means updates the old detection result of the storage means 8 to a new detection result when the detection result created in the tester 1 exceeds the old detection result read from the storage means 8. Has become.

The detection result and the comparing means are realized on a software program of a computer constituting the tester 1, and the storage means 8 is constituted by a nonvolatile memory provided in the ECU 2 in the present embodiment.

The reason why the nonvolatile memory 8 is provided in the ECU 2 in the illustrated example is that the mounting rate of the ECU 2, that is, the possibility that the ECU 2 is mounted on the vehicle is extremely higher than other control units. Any control unit that is likely to be installed as standard on the ECU is sufficient, and is not limited to ECU2.

FIG. 2 is a flow chart for explaining a portion of the vehicle failure diagnosis device shown in FIG. 1 according to the present invention.

First, a low pulse is transmitted from the tester 1 to the control unit (S1). If there is a reply to the low pulse (YES), the bit 1 is set to the corresponding part of the inspection table (shown in FIG. 3) in the tester 1. Write (S2, S3), if there is no reply (NO), the bit of the corresponding part is set to 0 in the initial state. Next, a clock signal is transmitted from the tester 1 to the control unit (S4), and if there is a reply to the clock signal (YES), the bit 1 is written in the corresponding part of the inspection table (S5, S6), If there is no reply (NO), the bit of the corresponding part is set to 0 in the initial state.

That is, the control unit (control unit) mounted on the vehicle is capable of performing one-way low-speed communication in which a failure code is returned in response to a low pulse sent from the tester 1. Tester 1
Some of them can also perform bidirectional high-speed communication in which various failure diagnoses are made in response to a clock signal sent from the controller, and S1 to S6 detect which of them is required. Then, S1 to S6 are repeated for all control units connected to the centralized connector 4 (S7), and the results are tabulated in the tester 1.

The table of the detection results in S1 to S7 described above at the time of completion of the manufacture or maintenance of the vehicle is stored in the above-described nonvolatile memory 8, and is backed up as an old detection result in preparation for the next maintenance.

When performing maintenance for a vehicle for which the detection result is stored for a considerable period of time after service, the detection is performed in the following procedure.

First, prior to various failure diagnoses by the tester 1, a check table for the current mounting status of the control unit is created in the tester 1 in S1 to S7. At this time, since there is no communication between the tester 1 and each control unit if there is any abnormality such as disconnection of the communication path 5 or failure of the control unit itself, the inspection table created here includes: Only control units that can currently communicate with the tester 1 are listed.

Next, the current detection table is compared with the previous old detection result table stored in the nonvolatile memory 8 (S8). If there is no change (NO), there is no additional control unit option. In addition, since it can be determined that communication is possible with all the control units connected to the centralized connector 4, the inspection is completed (S9). on the other hand,
If there is any difference (YES), it is determined whether or not the number of bits has increased (S10).

Here, if the number of bits in the inspection table at the present time is increased compared to the table of the previous old detection result (YES), it is possible to add a new option of the control unit. (S11), and after confirmation by the serviceman, updates the contents of the nonvolatile memory 8 (S12). Conversely, if the number of bits is reduced (NO), it is considered that some sort of situation has occurred that may have prevented communication with the control unit whose number of bits has been reduced. The control unit is determined based on the comparison with the table (S13), and a warning to notify them is issued (S14).

That is, according to such a configuration, the nonvolatile memory 8
Since the previous detection result table is stored and backed up, the stored control unit can be reliably listed up by reading out the stored contents from the nonvolatile memory 8 at the time of failure diagnosis. In addition, maintenance can be performed more easily and without oversight as compared with a conventional method in which each control unit is visually checked and listed.

Also, since the control units listed in the inspection table in the tester 1 in S1 to S7 described above are only those that can be communicated at present, comparison with the previous old detection result table backed up in the nonvolatile memory 8 is made. By checking the current status of the control units and the electronic control system installed in the vehicle, such as indexing control units that are unable to communicate, that is, control units that may have a failure, and adding options, And appropriate failure diagnosis can be performed.

<< Effects of the Invention >> As described in detail in the above embodiments, according to the vehicle failure diagnosis apparatus according to the present invention, the control unit communicable with the tester is detected by the detection unit, and the detection result is stored in the storage unit. Since it is stored as the old detection result, when the manufacture or maintenance of the vehicle is completed, if the control unit connected to this is detected by the detection means using the tester and stored in the storage means, the next time a failure diagnosis is made ,
By reading the old detection result from the storage means, the control unit mounted and stored before the current failure diagnosis can be reliably listed without overlooking it. This can improve maintainability and eliminate service errors.

Also, by comparing the old detection result at the time of the previous failure diagnosis with the detection result at the time of the current failure diagnosis by the comparing means, it is possible to easily and reliably grasp the current mounting state of the control unit and the increase / decrease thereof. From this aspect, it is possible to improve the maintainability and eliminate service errors.

Furthermore, by generating a warning when the current detection result is less than the old detection result, it is possible to easily find a control unit that is unable to communicate.

In addition, by updating the storage unit when the current detection result exceeds the old detection result, the latest detection result can be always stored in the storage unit, and this can be effectively used at the next failure diagnosis. Can be used.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a preferred embodiment of a vehicle failure diagnosis apparatus according to the present invention, FIG. 2 is a flowchart for explaining its operation, and FIG. 3 is a view showing the contents of a table. 1… Tester 2,20 ～ 23 …… In-vehicle electrical component control unit (ECU, electronically controlled automatic transmission, antilock brake, electronically controlled power steering, air conditioner) 3 …… Storage means (non-volatile memory)

Claims (5)

(57) [Claims] 1. A tester for communicating with the on-vehicle electrical component control unit is connected to each of the on-vehicle electrical component control units, and information for failure diagnosis is individually transmitted and received between the tester and each of the control units. In the vehicle failure diagnosis device, a detection unit provided in the tester, for detecting whether the tester and each of the control units can communicate with each other at the time of failure diagnosis, and generating a detection result in the tester; Storage means provided in any one of the units for use in the vehicle, and storing the detection result detected by the detection means at the time of the previous failure diagnosis as an old detection result so as to be readable by the tester. Failure diagnosis device. 2. The fault diagnosis device for a vehicle according to claim 1, wherein the storage means is provided in a control unit which is likely to be provided as a standard among the control units. 3. The apparatus according to claim 1, wherein said tester further comprises a comparing means for comparing said detection result created in said tester with said old detection result read from said storage means. The fault diagnosis device for a vehicle according to the above. 4. The apparatus according to claim 1, wherein the comparing unit generates a warning when the detection result created in the tester is less than the old detection result read from the storage unit. 4. The failure diagnosis device for a vehicle according to 3. 5. The comparison means according to claim 1, wherein said comparison result is obtained when said detection result created in said tester exceeds said old detection result read from said storage means. The vehicle failure diagnosis device according to claim 3, wherein the detection result is updated to a detection result.