JP3031050B2 - Fault diagnosis device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a failure diagnosis device which is installed in a service station or the like and diagnoses a failure of an electronic control unit mounted on an automobile or the like.

[0002]

2. Description of the Related Art In recent years, for various control devices for automobiles, for example, electronic control devices using microcomputers have been used in order to improve control accuracy and responsiveness.
In order to diagnose whether or not the electronic control device is functioning normally, a service station such as a dealer is connected to the electronic control device on the vehicle and transmits and receives diagnostic data by two-way communication. Failure diagnosis device is installed. In response to this, the electronic control unit of the vehicle monitors input signals from various sensors and output signals to the actuators, and outputs input signals and output signals necessary for diagnosis in response to a request from the failure diagnosis device. The data is sent to the failure diagnosis device.

[0003] Taking an automobile as an example, a failure diagnosis device can be diagnosed regardless of the type of the vehicle, regardless of whether the device has been developed specifically for a specific vehicle or a specific item required by law. Various types, such as stuff, are already offered. Each of these vehicle failure diagnosis devices employs a unique diagnosis function and protocol. In response to this, the vehicle electronic control unit is adapted to be able to handle a plurality of failure diagnosis devices. One interface can handle multiple protocols. In other words, the electronic control unit automatically switches the protocol when a failure diagnosis device with a different protocol is connected, and aims at saving labor for switching the protocol.

[0004]

However, when a failure diagnosis device is connected to the above-described electronic control device and data of a different protocol is erroneously transmitted from the electronic control device side of the vehicle during the failure diagnosis work. , A communication error occurs, and communication must be restarted from the initial state.
It was difficult to ensure continuity of the diagnostic function. In particular, when used as a failure diagnosis device for an electronic control unit for a vehicle, in the case of a difficult failure that often occurs and is difficult to reproduce, there is a possibility that the failure phenomenon may be lost while communication is restarted.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a failure diagnosing device which ensures continuity of a diagnostic function even when a protocol error occurs, in view of the above-mentioned conventional problems.

[0006]

SUMMARY OF THE INVENTION For this reason, the present invention has been described with reference to FIG.
Is connected to the electronic control unit 2 to be diagnosed having a protocol switching function, and a plurality of diagnostic functions are provided.
From the program A fault diagnosis device having a diagnosis means 10 for executing the configured diagnostics, and the electronic control unit determines the protocol determining means 12 the protocol of diagnostic data received from said protocol determining
If it is determined that the protocol of the diagnostic data received by the means is different from the protocol of the failure diagnostic device ,
Diagnostic function suspending means 14 for temporarily suspending the execution of the diagnostic program; protocol change request signal transmitting means 16 for requesting the electronic control device to change the protocol; and when the protocol of the diagnostic data matches the protocol of the failure diagnostic device. The diagnostic function at the time of the pause
The diagnostic function resuming means 18 for resuming the execution of the diagnostic program from the program is provided.

[0007]

When the diagnostic data having different protocols is received, the diagnostic function suspending means suspends the execution of the diagnostic program in the diagnostic means at that time.
Transmission of a protocol change request signal to the electronic control device 2 instructs the electronic control device to switch the protocol. When the protocol returns to normal, diagnostic function restart means 1
8 that the diagnostic means 10 has temporarily stopped first.
Running the diagnostic program from the program according to the Kino diagnosis function is resumed.

[0008]

FIG. 2 shows an embodiment of the present invention. A failure diagnostic device 5 is connected via a diagnostic cable 4 to a diagnostic connector 3 of an electronic control unit 2 mounted on an automobile 1. The failure diagnosis device 5 includes an I / O interface 52 for performing bidirectional communication, an internal memory 56, and a CPU 54, and operates under the control of the CPU 54. Further, the failure diagnosis device 5 is provided with a touch screen 7 for inputting a failure diagnosis part, a failure item, and the like. The touch screen 7 also serves as a display for displaying a diagnosis result. Further, the failure diagnosis device 5 also includes a printer 8, and can print out a diagnosis result.

Further, a ROM card 6 as an external memory
The ROM card 6 stores programs and data necessary for failure diagnosis.
The failure diagnosis device 5 reads a diagnosis program and data required for failure diagnosis from the ROM card 6 into the internal memory 56 of the failure diagnosis device, and then removes the ROM card 6 to perform failure diagnosis. The ROM card 6 is updated and the contents are read into the internal memory 56 of the failure diagnosis device when the vehicle-side electronic control device to be diagnosed changes or when a new electronic control device is added to the vehicle. Perform the corresponding diagnosis with.

Further, as shown in FIG. 3, the vehicle-side electronic control device 2 includes an interface 22 for performing bidirectional communication with the failure diagnosis device 5 through the diagnosis connector 3 for processing received data and transmitting data. And a memory 25 storing programs such as system control and diagnostic functions are connected to the interface 22. The interface 22 further includes
The protocol determining means 23 for determining the protocol of the consulted data and the protocol switching means 24 for switching the protocol of the transmission data based on the determination result of the protocol determining means 23 are connected. Thus, a function is provided in which one interface supports each protocol of a plurality of failure diagnosis apparatuses and automatically switches the protocol when data of a different protocol is received. Specifically, the protocol determining unit 23 and the protocol switching unit 24 are also configured by the CPU together with the arithmetic unit 21.

Next, the flow of the operation during the execution of the failure diagnosis is shown in FIG.
And shown in FIG. In the failure diagnosis device 5, in step 110, a diagnosis program stored in the internal memory storage unit 56 is executed in units of a diagnosis function according to a signal input from the touch screen 7. Here, first, a diagnosis request signal is sent to the electronic control unit 2, and a diagnosis is performed based on the diagnosis data sent from the electronic control unit 2 in response thereto.

Each diagnostic function is used as a diagnostic program
In the course of the program are sequentially executed, or one of the diagnostics
After Cal program execution, it is checked whether it meets the termination condition of the diagnosis at step 120, the diagnosis end become if they meet. If the diagnosis has not been completed, the routine proceeds to step 130, where it is determined whether the protocol of the diagnostic data transmitted from the electronic control unit 2 is the same as the protocol of the failure diagnostic device 5. If it is determined in step 130 that the data according to the same correct protocol as that of the failure diagnosis device 5 has been received, the diagnosis is directly performed.
The process proceeds to the execution of the program for the next diagnostic function in the disconnection program . If it is determined that data having a different protocol has been received, the process proceeds to step 140, and the execution of the diagnostic program is temporarily stopped. At this time, which diagnostic function
Remembers whether you were trying to execute a program
It is.

In step 150, a protocol change request signal is transmitted to the electronic control unit 2 according to the protocol of the failure diagnosis device 5. When new data is sent from the electronic control unit 2 by the operation described below,
In step 160, it is determined whether or not the protocol of the data is the same correct protocol as the protocol of the failure diagnosis device 5. Steps 150 to 160
Is repeated until diagnostic data according to the correct protocol is received. Then, when the diagnostic data of the correct protocol is received, in step 170, the execution of the diagnostic program is restarted from the program related to the diagnostic function suspended in the previous step 140.

Of the above steps, step 110 constitutes the diagnostic means of the invention, steps 130 and 160 constitute a protocol determining means, step 140 constitutes a diagnostic function suspending means, step 150 constitutes a protocol change request signal transmitting means, Step 170 constitutes the diagnostic function resuming means.

In the vehicle-side electronic control unit 2, step 2
In 10, based on a diagnosis request signal from the failure diagnosis device 5 input from the interface 22, the memory 25
And transmits the diagnostic data to the failure diagnostic device 5 via the interface 22. After the execution of the diagnostic program, it is checked in step 220 whether or not the condition for terminating the diagnosis is satisfied, and if so, the diagnosis is terminated. If the diagnosis is not completed, the process proceeds to step 230, where the protocol of the data transmitted from the failure diagnosis device 5 is determined by the protocol determination unit 23.

In step 230, the electronic control unit 2
If the protocol of the diagnostic data transmitted from the device and the protocol of the data received from the failure diagnostic device 5 are the same,
The process directly proceeds to the execution of the diagnostic program for the next item. If the protocols do not match, such as when a protocol change request signal issued from the failure diagnosis device 5 is received in step 150, the process proceeds to step 240,
The protocol of the currently transmitted diagnostic data is switched. Steps 230 to 240 are repeated each time data is received from the failure diagnosis device 5.

In the above-described embodiment, the description has been given of the case where the diagnosis target is connected to an electronic control unit for a vehicle. However, the present invention is not limited to this, and the present invention can be applied to a case where there are a plurality of electronic control units.

[0018]

As described above, according to the present invention, the protocol of the data received from the vehicle-side electronic control unit is determined, and when data having a different protocol is received, the diagnostic program is executed.
Sending a protocol change request signal as well as pause program, stop one o'clock when receiving the data of the correct protocol from the electronic control unit having a protocol switching function
Since the program related to the stopped diagnostic function is restarted, even if data with a different protocol is received from the electronic control unit during diagnosis, there is no need to restart communication from the initial state, and continuity of the diagnostic function is ensured. You.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of the present invention.

FIG. 2 is a diagram illustrating an overall configuration of an embodiment.

FIG. 3 is a block diagram illustrating a configuration of an electronic control unit.

FIG. 4 is a flowchart showing the operation of the embodiment apparatus.

FIG. 5 is a flowchart showing the operation of the electronic control unit.

[Explanation of symbols]

 Reference Signs List 1 automobile 2 electronic control unit 3 diagnostic connector 4 diagnostic cable 5 failure diagnostic device 6 ROM card 7 touch screen 8 printer 10 diagnostic means 12 protocol determination means 14 diagnostic function suspending means 16 protocol change request signal transmitting means 18 diagnostic function resuming means 21 arithmetic Unit 22 I / O interface 23 protocol determination means 24 protocol switching means 25 memory 52 I / O interface 54 CPU 56 internal memory

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kazuyoshi Nukawa 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd. (56) References JP-A-3-269632 (JP, A) (58) Survey Fields (Int.Cl. ⁷ , DB name) G01M 17/00-17/007 G08C 25/00 H04L 29/06 G06F 13/00 351

Claims (1)

(57) [Claims] An electronic control unit to be diagnosed having a protocol switching function is connected to a plurality of diagnostic functions.
A failure diagnosis device having a diagnosis means for executing a diagnosis program comprising a diagnosis program, the protocol determination means for determining a protocol of diagnosis data received from the electronic control device, and the diagnosis data received by the protocol determination means. Is determined to be different from the protocol of the failure diagnosis device.
Diagnostic function suspending means for temporarily suspending the execution of the diagnostic program at that time; protocol change request signal transmitting means for requesting the electronic control device to change the protocol; and When they match, the diagnostic function when the
A failure diagnostic device comprising diagnostic function restart means for restarting execution of a diagnostic program from such a program .