JPH05172704A - Trouble diagnosing apparatus for vehicle - Google Patents

Abstract

PURPOSE:To specify the place of a trouble properly in accordance with the result of determination as to whether the trouble of a sensor, an actuator or the like is a continuous trouble or a transient one. CONSTITUTION:A continuous/transient trouble determining means 81 determines whether a trouble of a sensor or the like detected by a self-diagnosing means 52 is a continuous trouble or a transient one. Operation instructions, places of troubles and details thereof are stored beforehand in first and second diagnosis program means 82 and 83 and an operation instruction is outputted to a display means 63 in accordance with the result of the determination as to whether the trouble is the continuous trouble or the transient one. When an operator executes an operation in conformity with the operation instruction and prescribed conditions are met, the place of the trouble and the details thereof are displayed in the display means 63 and thereby the place of the trouble is specified. When the prescribed conditions are not met, a subsequent operation instruction is outputted to the display means 63.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle failure diagnosis device, and more particularly to a failure of a sensor or the like, which is a failure of the sensor itself or a continuous failure caused by a wire harness disconnection or the like. The present invention relates to a vehicle failure diagnosis device capable of performing appropriate failure diagnosis depending on whether the failure is a transient failure caused by poor contact of a connector or the like connecting to an electronic control device.

[0002]

2. Description of the Related Art As is well known, in automobiles, motorcycles, etc. (hereinafter simply referred to as "vehicles"), various sensors are attached to the vehicle and various vehicle controls are performed by using the outputs of the sensors. The drive actuator is controlled. Such control is performed by an electronic control device equipped with a microcomputer.

By the way, the electronic control device as described above has a self-diagnosis function and is constructed so as to be able to detect failures in various sensors and actuators. And
When such a failure is detected, the data to that effect is stored in the storage device (for example, RAM) of the electronic control unit.

This data is read from the storage device by using a vehicle failure diagnosis device, for example, when the vehicle is serviced. If there is data indicating a sensor failure, the sensor is replaced or the like according to the content of the data. .. Such a failure diagnosis device is described in Japanese Patent Laid-Open No. 64-52551.

[0005]

The detection of a failure of a sensor or the like by the electronic control device as described above is, more precisely, a failure detection of a sensor side line including a wire harness or a connector from a microcomputer in the electronic control device. Is. Therefore, even if the electronic control unit detects a sensor failure,
The failure is a continuous failure such as a failure of the sensor itself or disconnection of the wire harness (that is, a failure in which the abnormal state is maintained once the failure or disconnection occurs. Hereinafter, it is referred to as "continuous failure". ), Or a failure such as a contact failure of the sensor or wire harness, or the connector that connects the wire harness and the electronic control device, and the abnormal condition does not continue (that is, contact due to vibration etc. while the vehicle is running). A failure that causes or does not cause a defect, etc. Hereinafter referred to as a "transient failure".)
Cannot be determined.

As described above, in the conventional failure determination by the electronic control device, it is not possible to determine whether the failure is a continuous failure or a transient failure, and it is determined that all the failures are continuous failures. , Even if the electronic control unit detects a sensor failure or wire harness disconnection (continuous failure), it is necessary to further investigate the contact failure of the connector (transient failure) using other suitable means. It was

Then, even after the determination as to whether the failure is a continuous failure or a transient failure, it is determined whether the failure is the failure of the sensor itself or the failure of the connector or the wire harness connecting the sensor. The failure location must be specifically identified, but the specific means for this identification has not been established, making it difficult to diagnose the failure of the vehicle.

The present invention has been made in order to solve the above-mentioned problems, and its purpose is to determine whether a continuous failure or a transient failure has occurred, and then determine the result. Accordingly, it is an object of the present invention to provide a vehicle failure diagnosis device capable of appropriately identifying a failure location.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention detects a failure of a sensor, an actuator or the like by a self-diagnosis function of an electronic control device, and according to the detection result, After the failure is determined by the continuous / transient failure determination means to be a continuous failure or a transient failure, the vehicle concerned is specified in order to identify the failure location according to the mode of each failure. It is characterized in that it has a diagnostic program for giving a predetermined work instruction to the operator of the failure diagnosing device.

That is, in the vehicle failure diagnosis device according to the first aspect of the present invention, when the sensor, the actuator, etc. are in continuous failure, a work instruction and a work instruction in which the failure diagnosis and the determination standard corresponding to the work instruction are stored. And the like, and a work instruction in the case where the first diagnostic program means and its sensors, actuators, etc. are transient failures,
Also, a second diagnostic program means that describes a work instruction or the like that stores failure diagnosis and determination criteria corresponding to the work instruction, and a test probe that outputs a reference value of the sensor, actuator, or the like when a continuous failure is determined. And a switching means for controlling the output of the reference value to the test probe, and when the reference value is output from the test probe, or when a transient failure is determined by the continuous / transient failure determination means. According to the comparison means for determining whether the output signal of the electronic control unit is within the range of the reference value, the determination result of the continuous / transient failure determination means, and the determination result of the comparison means. , The first and second
It is characterized in that a display means for displaying the stored contents of the diagnostic program means and a judgment standard are provided.

Further, the vehicle failure diagnosis device according to the present invention further comprises a reference value storage means for storing a plurality of types of reference values corresponding to the sensors, actuators, etc. connected to the electronic control unit. The point is characteristic.

[0012]

In the vehicle failure diagnosis apparatus according to the first aspect of the present invention, first, when there is a continuous failure, a work instruction (a connector name and an instruction to remove the connector, and a plurality of connectors are provided from the first diagnosis program means). When the wire harnesses are connected, the color of the wire harnesses), the failure location and the failure content corresponding to the work instruction are read out, and the work instruction is displayed on the display device. With this display,
When the operator of the vehicle failure diagnosis device removes the displayed connector and contacts the predetermined wire harness with the test probe, the test probe outputs a reference value. Then, it is determined whether the reference value output from the test probe is output from the electronic control device, and if detected, the failure location and failure content corresponding to the displayed work instruction are displayed, and the failure is not detected. In this case, the next work instruction is displayed on the display device.

Further, in the case of a transient failure, a work instruction (a connector name and an instruction to shake the connector) and a failure location and a failure content corresponding to the work instruction are read from the second diagnostic program means. Of these, the work instruction is displayed on the display device. With this display, when the operator of the vehicle failure diagnosis device shakes the displayed connector, it is determined whether or not the output signals of the sensor, actuator, etc. are within the range of the reference value. If the output signal is within the range of the reference value, the failure location and the failure content corresponding to the displayed work instruction are displayed, and if not detected, the next work instruction is displayed on the display device.

According to another aspect of the vehicle failure diagnosis device of the present invention,
At the time of the determination by the continuous / transient failure determination means, the reference value corresponding to the sensor, actuator, etc. is read from the reference value storage means.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings. FIG. 2 is a block diagram showing a hardware configuration of an electronic control unit (hereinafter referred to as “ECU”) of a vehicle to be diagnosed according to an embodiment of the present invention. In FIG. 1, the ECU 1 includes a CPU 10 and a ROM 11 which constitute a microcomputer.
And RAM 12, driver 13, A / D converter 1
4 and a communication interface 15 are provided. The ECU 1 is connected to peripheral devices by connectors 16 and 17. Further, the failure diagnosis device 2 described later can be connected to the connector 18.

The connector 16 has various actuators 3
, And various sensors 4 are connected to the connector 17. The ECU 1 performs ignition timing control, electronic fuel injection device (EFI) control, and the like. For example, when performing EFI control, a solenoid is connected to the connector 16 as an actuator 3 and a sensor 4 is connected to the connector 17. As a TDC sensor, a water temperature sensor, an intake air temperature sensor, a throttle valve opening sensor, etc. are connected. In addition, this E
The CU 1 may be any control as long as it controls the vehicle.

A signal input from each sensor 4 to the ECU 1 is converted into a digital signal by the A / D converter 14 and then converted into a CP signal.
Captured by U10. The signal captured by the CPU 10 is
Based on the control data stored in the ROM 11 and the RAM 12, it is processed according to the program written in the ROM 11. An instruction signal is input to the driver 13 according to the processing result of the CPU 10, and the driver 13 supplies power to the actuator 3 in response to the instruction signal.

In addition to the program, the ROM 11 also stores the identification code of the ECU 1, that is, the ECU-ID. Further, the RAM 12 stores the processing result of the CPU 10 as learning data or freeze data. This freeze data is data representing the engine operating state when a malfunction occurs.

The failure diagnosing device 2 connected to the ECU 1 for diagnosing the failure of the ECU 1 includes a CPU 20, a ROM 21 and a RAM 2 which constitute a microcomputer.
2, a driver 23, an A / D converter 24, and a communication interface 25 are provided. In addition, the failure diagnosis device 2 is provided with a keyboard 26 for inputting an instruction by an operator and a display device 27 for displaying a processing result by the CPU 20. The keyboard 26 is provided with general numeric keys, cursor movement keys, function keys and the like. A liquid crystal display panel (LCD) can be used as the display device 27.

A test probe 6 is connected to the failure diagnosis device 2 in order to add a voltage / resistance measuring function as a tester function and a test signal (reference value described later) output function.
That is, by supplying the voltage output from the driver 23 to the test probe 6, the test probe 6 can output the test signal of the sensor 4. On the other hand, the signal detected by the test probe 6 is the A / D converter 24.
Can be converted into a digital signal and taken into the CPU 20.

The communication interface 15 of the ECU 1 and the communication interface 25 of the failure diagnosing device 2 are connected via a cable 5 so that two-way digital communication can be performed between the CPUs 10 and 20.

The signal fetched from the ECU 1 and the signal obtained by the test probe 6 are stored in the ROM 21 and the RAM 22.
Processing is performed based on the control data stored in, and the processing result, that is, the failure diagnosis result is output to the display device 27. The failure diagnosis program is registered in the ROM 21. A plurality of failure diagnosis programs are prepared to enable failure diagnosis suitable for many vehicles.

The ROM 21 stores VIN and a selection program for selecting the optimum one from the plurality of failure diagnosis programs based on the VIN and the ECU-ID. For this selection program,
Since it is not directly related to the present invention, its explanation is omitted.

It should be noted that the VIN may be added or changed with the production of the new model. For such a case, the VIN and the selection program may be stored in the ROM card 7 so that the data of the ROM card 7 can be taken into the CPU 20 from the ROM card interface 28. It should be noted that a ROM card can be used to add a fault diagnosis program.

It is also possible to connect the failure diagnosis device 2 to a personal computer (not shown), store the failure diagnosis result in this personal computer, and print it out if necessary. Further, the personal computer can be connected to a host computer via a public line, and the failure diagnosis result can be supplied to the host computer. On the contrary, the host computer may provide the personal computer and the failure diagnosis device 2 with necessary information, for example, the updated failure diagnosis program or the selected program (version upgrade). it can.

The failure diagnosis device 2 preferably has a built-in battery as a power source so that it can be carried away from the repair shop, and this battery can also be supplied with power from the vehicle battery via the socket of the writer. , Ni—Cd batteries and the like are more preferable as long as they are rechargeable.

Next, when a failure of the sensor is detected by the self-diagnosis function of the ECU 1 mounted on the vehicle, the failure data is used to determine whether the failure is a continuous failure or a transient failure. A configuration for making a determination (hereinafter referred to as "continuous / transient failure determination") will be described.

FIG. 3 is a flow chart showing an example of the continuous / transient failure determination operation. The operation of FIG. 3 is executed in a state where the failure diagnosis device 2 is connected to the ECU 1 of the vehicle. In FIG. 3, first in step S1, the ECU 1
Data indicating the name of the faulty sensor and the details of the fault (hereinafter referred to as “fault code”) is read from the RAM 12 and stored in the RAM 22 in the fault diagnosis device 2. The data indicating the details of the failure can be, for example, an output signal (voltage value) of the sensor. When the system voltage input to the sensor is, for example, DC 5 [V], when the sensor is normal, the output voltage is, for example, 0.05 to
It is 4.95 [V], and 0.0 when the sensor is short-circuited to the ground side and when there is a wire breakage fault.
It becomes 5 [V] or less and 4.95 [V] or more. In addition,
At the time of this reading, the name of the faulty sensor or the like may be displayed on the display device 27.

In step S3, the ECU 1 is reset, the fault code in the RAM 12 is erased, and then the self-diagnosis program of the ECU 1 is started. Then, in step S4, it is determined whether or not the same failure code as the failure code detected in step S1 is detected. If the same fault code is detected, it is determined to be a continuous fault in step S8, and if a different fault code is detected (for example, it was determined that the wire was disconnected earlier, but later it was determined that the ground side was short-circuited). When the failure mode is different, or when the failure code is not output (that is, when the failure code is output in step S1 but the failure code is not detected during the self-diagnosis in step S3, or (In the opposite case), it is determined to be a transient failure in step S9. In each failure determination, the name of the failed sensor, the failure status, etc. are displayed on the display device 27 of the failure diagnosis device 2 as necessary.

Then, in step S10, it is determined whether or not there is another faulty part. If the determination is affirmative, the process returns to step S4, and if the determination is negative, the process ends.

FIG. 4 is an ECU for executing the operation of FIG.
1 is a functional block diagram of a failure diagnosis device 2 and FIG. In the figure, the same reference numerals as those in FIG. 2 represent the same or equivalent parts. In FIG. 4, the vehicle control device 51 in the ECU 1 uses the output signal of the sensor 4 to control the actuator 3 in a predetermined procedure. The self-diagnosis means 52 detects an abnormality of the sensor 4 at the start of control by the vehicle control device 51 and during control as needed. When an abnormality is detected, the failure code is stored in the failure code storage means 53.

The switching means 61 of the failure diagnostic device 2 always selects the first failure code storage means 62. Then, at the time of failure diagnosis, the failure code stored in the failure code storage means 53 is transferred and stored in the first failure code storage means 62 via the communication control means 54 and 74.

When the failure code is stored in the first failure code storage means 62, the fact and the sensor name of the failure are displayed on the display means 63, if necessary. Then, the switching means 61 is switched to the second failure code storage means 65 side, the failure code storage means 53 is reset, and the self-diagnosis means 52 is activated again. As a result, the sensor failure detection is performed again, and the failure code is stored in the failure code storage means 53.

The failure code stored in the failure code storage means 53 is transferred to and stored in the second failure code storage means 65 this time. The code selection means 66 stores the failure code of the failed sensor in the first failure code storage means 62 and 6.
5 are sequentially extracted, and each is transferred to the failure state determination means 69.

The failure state judging means 69 executes the judgment of step S4 of FIG. 3 and detects a positive judgment of the step, that is, when the failure codes stored in the respective storage means 62 and 65 are equal. Is a "continuous failure", and when a negative determination in the above step is detected, it is determined to be a "transient failure", and the respective determination results are transferred to the display means 63.

FIG. 5 is a flowchart showing another example of the continuous / transient failure determination operation. In the figure, the same reference numerals as those in FIG. 3 represent the same or equivalent portions. The operation of FIG. 5 is also executed with the failure diagnosis device 2 connected to the ECU 1.

In FIG. 5, first in step S1, EC
When the failure code stored in the RAM 12 of U1 is accumulated in the RAM 22 in the failure diagnosis device 2, the output signal of the sensor corresponding to the accumulated failure code is detected from the ECU 1 in step S5, and in step S6. The voltage value detected as described above is compared with a reference value for failure determination stored in advance in the failure diagnosis device 2. This reference value is, for example, a voltage value output when the sensor 4 is normal, and is provided and stored for each sensor 4 when the output voltages of the plurality of sensors 4 are different from each other.

In step S7, the detected voltage value and the reference value are compared with each other, and if they are the same failure mode, step S8 is carried out. If they are not the same failure mode, step S9 is carried out. , Respectively. Then, if it is determined in step S10 that there is another faulty part, the process returns to step S5, and if it is determined that there is no other failure part, the process ends.

When the output voltage value of the sensor in the normal state has a width, the intermediate value of this width is used as a reference value, and the output voltage value of the sensor is less than or equal to a predetermined voltage value or a predetermined voltage value from the reference value. When the value is equal to or more than the value, it may be determined that the ground side is short-circuited or disconnected, and when the lower limit value and the upper limit value of the width are used as reference values and the lower limit value is exceeded or the upper limit value is exceeded. Alternatively, it may be determined as a short circuit or a disconnection.

FIG. 6 is an ECU for executing the operation of FIG.
1 is a functional block diagram of a failure diagnosis device 2 and FIG. In the figure, the same reference numerals as those in FIGS. 2 and 4 denote the same or equivalent portions. In FIG. 6, the failure code stored in the failure code storage means 53 is the communication control means 54.
When it is transferred to and stored in the first failure code storage means 62 via Nos. 74 and 74, that effect and the name of the failed sensor are displayed on the display means 63, and the sensor selection means 70 is activated. It

The reference value storage means 71 stores the reference values of the respective sensors 4 as described above. Further, the sensor selection means 70 includes a first failure code storage means 62.
Based on the failure code stored in, the output signal of the failed sensor 4 is fetched through the communication control means 54 and 74 and output to the failure state determination means 69. Further, the reference value storage means 71 outputs to the determination means 69 the reference value of the sensor 4 corresponding to the output signal output to the failure state determination means 69. The failure state determination means 69 executes the processes of steps S6 and S7 using the output signal and the reference value.

After the failure code stored in the failure code storage means 53 is transferred to the first failure code storage means 62, the failure code storage means 53 is reset if necessary.

FIG. 7 is a flow chart showing still another example of the continuous / transient failure determination operation. In the figure, the same reference numerals as those in FIGS. 3 and 5 represent the same or equivalent portions. In addition, the operation of FIG.
It is executed while connected to CU1.

In FIG. 7, first, in step S1, the ECU
When the failure code stored in the RAM 12 of No. 1 is accumulated in the RAM 22 of the failure diagnosis device 2, the procedure for failure determination is selected in step S2. That is,
In the above-described first and second embodiments, different procedures (each of which is referred to as "first procedure" and "second procedure") are used to determine whether the failure is a continuous failure or a transient failure. Although the determination is made, which of the first and second procedures is used to perform the failure determination is selected in this step S2.

The selection in step S2 may be made by the operator of the failure diagnosis apparatus 2,
For example, if the content of the failure code read in step S1 is determined and all the failed sensors can be determined by the second procedure, the second procedure is selected and even one of the failed sensors is selected. The first procedure may be selected when the failure determination by the second procedure is impossible. That is, the failure determination is faster when the output signal of the sensor 4 is read as in the second procedure than when the self-diagnosis program of the ECU 1 is started as in the first procedure, so the second procedure is given priority. It is good to choose.

After selecting the procedure, steps S3 and S4,
Alternatively, in steps S5 to S7 and steps S8 and S9, it is determined whether the failure is a continuous failure or a transient failure.

If it is not determined in step S10 that there is another faulty part, the process ends. If it is determined that there is another faulty part, it is determined in step S11 whether the procedure selected in step S2 is the first procedure. If the first procedure is selected, the process returns to step S4, and if the second procedure is selected, the process returns to step S5.

FIG. 8 is an ECU for executing the operation of FIG.
1 is a functional block diagram of a failure diagnosis device 2 and FIG. In the figure, the same reference numerals as those in FIG. 2, FIG. 4 and FIG. 6 represent the same or equivalent portions, and therefore the description thereof will be omitted.
In FIG. 8, when the failure code stored in the failure code storage means 53 is transferred to and stored in the first failure code storage means 62, that effect and the name of the failed sensor are displayed on the display means 6.
3, and the procedure selection means 64 is activated.

The procedure selecting means 64 selects one of the first and second procedures by the method described above with reference to step S2 in FIG. If the first procedure is selected,
The failure determination is performed by the procedure as described with reference to FIG. Further, when the second procedure is selected, the failure determination is performed by the procedure described above with reference to FIG.

In the continuation / transient failure determination, it has been explained that it is determined whether the failure of the sensor 4 is a continuous failure or a transient failure. However, the failure of the actuator 3 is a continuous failure. It is also possible to detect if there is or a transient failure. That is, the self-diagnosis unit 52 shown in FIGS. 4, 6 and 8 includes a detection unit for detecting the resistance value of the actuator and a determination unit for judging whether the resistance value is a normal value or not. If the resistance value or the like is abnormal, a means for creating a failure code using the resistance value or the like may be provided.

Further, in FIGS. 6 and 8, each sensor 4
Although the reference value storage means 71 storing the reference value of 1 is provided, the storage means 71 is not necessary when the reference value of each sensor 4 is the same.

Next, an embodiment of the present invention will be described. The sensor 4 shown in FIG. 2 is connected to the ECU 1 via one connector 17 for simplification of the drawing, but in reality, it may be connected using two or more connectors. Many. An example of this is shown in FIG. In the figure, E
The CU 1 and the fault diagnostic device 2 are shown diagrammatically, and only one sensor is shown at 4A.

FIG. 10 is a flow chart showing the operation of one embodiment of the present invention. In the figure, first, step S2
In No. 1, when the ECU 1 detects a failure of the sensor 4 or the like, the failure code output from the ECU 1 is used,
It is determined whether the sensor failure is a continuous failure or a transient failure. When it is determined that there is a continuous failure, the continuous failure diagnostic program is executed in step S22. When it is determined that the failure is a transient failure, the transient failure diagnostic program is executed in step S23.

After the execution of step S22 or S23, it is determined in step S24 whether or not there is another faulty part. If yes, the process returns to step S21. If no, the process ends. ..

FIG. 11 is a flow chart showing details of the continuous failure diagnosis program shown in the step S22. In the figure, the processing enclosed by the broken line shows the processing by the operator of the failure diagnosis apparatus 2. In the figure, first, in step S31, a work instruction (in this case, a connector name and an instruction to remove the connector, and When the connector connects a plurality of wire harnesses, the color of the wire harness), the failure location and the failure content corresponding to the work instruction, and the reference value of the sensor connected to the connector are read. In the storage device, a work instruction, a failure location and a failure content corresponding to the work instruction, and a reference value are stored in advance for each sensor.

In the example of FIG. 9, the sensor 4A is connected to the ECU 1 from the ECU 1 side through the three connectors 17A to 17C, but in such a case, the work instructions are respectively given to the connector 17A. 17C and the instruction to remove the connector, and the failure location and failure content corresponding to them are as shown in FIG. 12, for example. Then, in the first step S31, for example, the connector closest to the sensor 4A (connector 17C in this case) is selected as the work instruction data, and the failure location and the content corresponding to the data are read.

The data shown in FIG. 12 corresponds to the sensor 4 shown in FIG.
When the vehicle equipped with the ECU 1 further includes another sensor, the failure diagnosis device 2 stores data as shown in FIG. 12 for each sensor.
Although only the connector name is shown in FIG. 12 as the work instruction, when the connector connects a plurality of wire harnesses (that is, a plurality of sensors) as described above, the sensor corresponding to the failure code is used. The color of the wire harness connected to is also stored as work instruction data.
Further, the data shown in FIG. 12 is merely an example, and the work instruction and the data such as the failure location and the content are
Alternatively, it is appropriately determined according to the ECU 1, the sensor, the actuator, and the like. Furthermore, “Applied voltage detection status” in FIG.
Indicates the determination result of step S35 described later,
“Detected” indicates a positive determination in the same step, and “not detected” indicates a negative determination in the same step.

In step S32, the read work instruction is displayed on the display device 27. In step S33, the operator of the failure diagnosis device 2 removes the displayed connector and connects the wire harness (if the connector is connected to a plurality of wire harnesses, a work instruction is issued). The test probe 6 is brought into contact with the specified color wire harness).

In step S34, it is determined whether or not the power application switch arranged on the keyboard 26 of the failure diagnosis device 2 has been pressed. When the switch is pressed, the test probe 6 outputs the reference value read in step S31.

In step S35, it is determined whether the ECU 1 has output a voltage signal substantially equal to the reference value. If it is output, the failure location and the failure content read out in step S31 are displayed in step S36, and then the process ends. That is, when the connector 17C is selected as a work instruction and an affirmative determination is made in step S35 immediately after that, as is apparent from FIG. 12, an internal disconnection of the sensor 4A is displayed.

If a voltage signal that is substantially equal to the reference value is not detected in step S35, the next work instruction is issued in step S37 (for example, an instruction to remove one connector on the ECU1 side from the already instructed connector). That is, in this case, an instruction to remove the connector 17B), and a failure location and content corresponding to the work instruction are read. The reference value is read in step S3.
Since it is executed in step 1, it is not executed in step S37.

In step S38, it is determined whether or not the data has been read in step S37. If the data has been read (that is, there is a connector to be removed), step S32.
If not performed (that is, the connector closest to the ECU 1 or the connector provided in the ECU 1 has already been removed), the process returns to step S3.
In 9, it is determined that, for example, the internal circuit of the ECU 1 has a failure, and that effect is displayed.

FIG. 13 is a flow chart showing details of the transient failure diagnosis program shown in step S23 of FIG. In the figure, the same reference numerals as those in FIG. 11 represent the same or equivalent portions, and the processing surrounded by the broken line shows the processing by the operator of the failure diagnosis device 2. In FIG. 13, first, in step S41, as in step S31 of FIG. 11, a work instruction (in this case, a connector name and an instruction to rock the connector) and the work instruction are issued from the storage device of the failure diagnosis device 2. The failure location and failure content corresponding to the above, and the reference value of the sensor connected to the connector are read. In the storage device, a work instruction, a failure location and a failure content corresponding to the work instruction, and a reference value are stored in advance for each sensor. FIG. 14 shows an example of the work instruction in this case, and the failure location and failure content corresponding to the work instruction.

In the example of FIG. 14, the work instruction read first is the connector 17C. Further, similar to FIG. 12, the data shown in FIG. 14 is also merely an example, and the work instruction and the data such as the failure location and the content are
It is appropriately determined according to the vehicle, the ECU 1, the sensor, the actuator, or the like. Further, "sensor output voltage" in FIG. 14 shows the determination result of step S45 described later, "abnormal" indicates an affirmative determination of the same step, and "no abnormality" indicates a negative determination of the same step.

In step S42, the read work instruction is displayed on the display device 27. And step S
In 43, the operator of the failure diagnosis device 2 is
The displayed connector shakes. In step S44, the output signal of the sensor detected via the ECU 1 (the output signal of the sensor connected to the shaken connector) is
It is compared with the reference value read in step S41.

In step S45, it is determined whether or not the output signal of the sensor is abnormal, that is, step S44.
As a result of the comparison, it is determined whether the output signal of the sensor has deviated from the reference value. If an abnormality (short circuit or disconnection) is detected even at the moment, the process goes to step S36. If no abnormality in the output signal is detected in step S45, step S3
Move to 7.

FIG. 1 is a functional block diagram of an embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 4, FIG. 6, FIG. 8 and FIG. 9 represent the same or equivalent portions. Figure 1
16A to 16D, actuators and EC
Connector for connecting to U1, reference numerals 17A to 17I
Is a connector for connecting the sensor and the ECU 1. Each connector may connect a plurality of sensors and actuators.

The continuous / transient failure determining means 81 of the failure diagnosing device 2 is used by the self-diagnosing means 52 to determine the failure on the sensor side by the method shown in FIG. 4, FIG. 6 or FIG. Of the line is a continuous failure or a transient failure.

The first diagnostic program means 82 is shown in FIG.
The data of the work instruction and the failure location and the failure content corresponding to the work instruction (hereinafter, referred to as “work instruction data”) related to step S31 of step S31 of each of the sensors 4A to 4A.
It is stored in correspondence with C. Similarly, the second diagnosis program means 83 stores the work instruction data described above with reference to step S41 of FIG. 13 in association with each of the sensors 4A to 4C.

When the continuous / transient failure determination means 81 determines a continuous failure, the sensor selection means 70 is energized to select the output signal line of the failed sensor and the reference value storage means 71. The reference value of the sensor is output to the comparing means 87, and the voltage corresponding to the reference value is output to the test probe 6 via the switching means 84 (normally open). In addition, the work instruction in the work instruction data corresponding to the sensor that has failed is read from the first diagnostic program means 82, output to the display means 63, and the ON detection means 86 is activated.

When the ON detection means 86 detects the ON state of the switching means 84 (that is, the display means 63).
According to the work instruction shown in, the failure diagnosis device 2
When the operator removes a predetermined connector, contacts the corresponding wire harness of the connector with the electrode of the test probe 6 and closes the switching means 84), the comparing means 87 is activated.

The comparing means 87 is a reference value storing means 71.
When the reference value output from the test probe 6 and the output signal of the ECU 1 input to the comparison means 87 via the communication control means 74 and the sensor selection means 70 are substantially equal (that is, substantially equal to the reference value output from the test probe 6). If an equal voltage signal is input to the comparing means 87 via the detached connector and the ECU 1), the display means 63 has already been output.
The failure location and the content corresponding to the work instruction displayed in are displayed on the display means 63. As a result, the failure position of one sensor can be specified.

When the comparing means 87 determines that the reference value and the output signal are not equal, the first diagnostic program means 82 is energized to display the next work instruction.
3, and the ON detection means 86 is activated again. Then, the processing as described above is executed again.

When the continuation / transient failure determination means 81 determines a transient failure, the sensor selection means 70 is energized to select the output signal line of the failed sensor and store the reference value. The reference value of the sensor is output from the means 71 to the comparison means 87. Further, the work instruction out of the work instruction data corresponding to the failed sensor is read from the second diagnostic program means 83 and output to the display means 63, and the comparison means 87 is energized.

When the operator shakes the predetermined connector displayed on the display means 63, and as a result, the output signal of the connector becomes a value (abnormal value) that deviates from the reference value even momentarily, the comparing means 87 has already detected The failure location and the content corresponding to the work instruction displayed on the display unit 63 are output to the display unit 63. As a result, the failure position of one sensor can be specified.

When the output signal does not deviate from the reference value, the comparing means 87 activates the second diagnostic program means 83 to display the next work instruction.
3 to output. Then, the processing as described above is executed again.

In this way, if the failure position of the sensor can be specified according to the continuous failure or the transient failure, the failure position of the next sensor is specified.

The continuous / transient failure determination is performed by the method shown in FIG. 3, FIG. 5 or FIG. 7, but these determination procedures are examples and are performed by any method. May be.

Further, in each of the above-described embodiments, it has been explained that it is determined whether the sensor failure is a continuous failure or a transient failure. However, the actuator failure is a continuous failure or a transient failure. It is also possible to detect whether there is a failure. When the actuator does not output a signal, the self-diagnosis means 52 shown in FIGS. 1, 5 and 7 is provided with a means for detecting the resistance value of the actuator and the resistance value etc. It is sufficient to provide a determination unit that determines whether or not the value is normal, and a unit that creates a failure code using the resistance value or the like when the resistance value or the like is abnormal. After the failure of the actuator is determined as described above, a specific failure position can be specified according to whether the failure is a continuous failure or a transient failure.
Since such a structure can be created more easily than the above description, the description thereof will be omitted.

[0080]

As is clear from the above description, according to the present invention, the following effects can be achieved.

(1) According to the vehicle failure diagnosis device of the first aspect, for identifying the failure location after it is determined that the failure of the sensor, actuator, etc. is a continuous failure or a transient failure. The work procedure can be sequentially instructed to the operator of the vehicle failure diagnosis device, so that the location of the failure can be easily identified.

(2) According to the vehicle failure diagnosis device of the second aspect, since the reference value is set according to the sensor, the actuator, etc., there is a difference in the output signals of the sensor, the actuator, etc. at the normal time. However, the location of the failure can be accurately identified.

[Brief description of drawings]

FIG. 1 is a functional block diagram of an embodiment of the present invention.

FIG. 2 is an embodiment of the present invention and an ECU of a vehicle to be diagnosed.
FIG. 3 is a block diagram showing the hardware configuration of the above.

FIG. 3 is a flowchart showing an example of a continuous / transient failure determination operation.

FIG. 4 is a functional block diagram of an ECU and a failure diagnosis device for executing the operation of FIG.

FIG. 5 is a flowchart showing another example of the continuous / transient failure determination operation.

FIG. 6 is a functional block diagram of an ECU and a failure diagnosis device for executing the operation of FIG.

FIG. 7 is a flowchart showing still another example of the continuous / transient failure determination operation.

FIG. 8 is a functional block diagram of an ECU and a failure diagnosis device for executing the operation of FIG.

FIG. 9 is a schematic diagram showing how the sensor is connected to the ECU via a plurality of connectors.

FIG. 10 is a flowchart showing the operation of the embodiment of the present invention.

11 is a flowchart showing details of a diagnostic program for continuous failure shown in step S22 of FIG.

FIG. 12 is an example of a work instruction corresponding to the sensor 4A for identifying a failure position during a continuous failure, an applied voltage detection status corresponding to the work instruction, and a relationship between a failure location and a failure content in the detection status. It is a chart showing.

FIG. 13 is a flowchart showing details of the transient failure diagnostic program shown in step S23 of FIG.

FIG. 14 is a relationship between a work instruction corresponding to the sensor 4A, an applied voltage detection status corresponding to the work instruction, and a failure location and a failure content at the detection status for identifying a failure position in the case of a transient failure. It is a chart showing an example.

[Explanation of symbols]

1 ... ECU, 2 ... Failure diagnosis device, 3 ... Actuator,
4A to 4C ... Sensor, 6 ... Test probe, 10, 20
... CPU, 11, 21 ... ROM, 12, 22 ... RAM,
15, 25 ... Communication interface, 16, 16A to 16
D, 17, 17A to 17I ... Connector, 26 ... Keyboard, 27 ... Display device, 52 ... Self-diagnosis means, 63 ... Display means, 70 ... Sensor selection means, 71 ... Reference value storage means,
81 ... Continuation / transient failure determination means, 82 ... First diagnostic program means, 83 ... Second diagnostic program means, 84 ... Switching means, 85 ... Voltage application means, 86 ... ON detection means, 87 ... Comparison means

Claims (2)

[Claims] 1. An electronic control unit for a vehicle, comprising a self-diagnosis means for diagnosing a failure of a connected sensor, actuator, etc., and creating failure information according to the result, and outputting the output of the self-diagnosis means. Based on the above, in a vehicle failure diagnosis device including a continuous / transient failure determination means for determining whether a failure of the sensor, the actuator, or the like is a continuous failure or a transient failure, the electronic control device Communication control means for performing data communication with, and a first diagnosis in which a work instruction and a work instruction in which a failure diagnosis corresponding to the work instruction and a determination criterion are stored when the sensor, the actuator, and the like are continuously failed are described. When the program means and its sensors, actuators, etc. are transient failures, work instructions and failure diagnosis and judgment criteria corresponding to the work instructions are stored. The second description of work instructions
Diagnostic program means, a test probe that outputs a reference value of the sensor, actuator, etc. when a continuous failure is determined by the continuous / transient failure determination means, and output of the reference value to the test probe When a reference value is output from the switching means and the test probe, or when a transient failure is determined by the continuous / transient failure determination means, the output signal of the electronic control unit is the reference value. Comparing means for determining whether or not it is within a range, the first / second diagnostic program for each failure event according to the determination result of the continuous / transient failure determination means, and the determination result of the comparison means. A failure diagnosis device for a vehicle, comprising: a display means for displaying the stored contents of the means and a criterion. 2. A plurality of kinds of reference values corresponding to the sensors, actuators, etc. are stored for each of them, and the sensors judged at the time of judgment by the continuous / transient failure judging means,
2. The vehicle failure diagnosis device according to claim 1, further comprising a reference value storage unit that reads out a reference value of an actuator or the like and outputs the reference value to the comparison unit.