JP2801927B2 - Vehicle failure diagnosis device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION << Industrial application field >> This invention diagnoses a failure of a vehicle-mounted electronic control system by transmitting a test signal to a control unit that controls the vehicle-mounted electronic control system such as an engine control unit. The present invention relates to a vehicle failure diagnosis device provided with a tester that performs the test.

<< Conventional technology >> As for a vehicle failure diagnosis device, for example,
JP-A-63-135250, and a control unit (for example, a control unit that controls a vehicle-mounted electronic control system by controlling various vehicle-mounted electric components such as various actuators and sensors.
There is also known a vehicle failure diagnosis device configured by connecting a tester for failure diagnosis to an engine control unit for electronically controlling an engine). In the failure diagnosis by such a vehicle failure diagnosis device, for example, in the failure diagnosis of an injector, which is one of the actuators controlled by the engine control unit, the tester sends the engine control unit to the engine control unit in the engine operating state. A test signal for individually stopping the operation is sent to the injectors, that is, a forcible stop command is sent to the injectors of the specific cylinders, and changes in engine behavior are monitored visually and by sound, and the injectors are forcibly stopped for one cylinder. However, if there is no change in the engine behavior despite this, it can be diagnosed that there is some abnormality in the injector of the cylinder, and a failure can be diagnosed.

<< Problems to be Solved by the Invention >> By the way, for example, even when the above-described engine control unit is connected to a tester for failure diagnosis, the actuator of the on-vehicle electronic control system controlled by the tester is controlled according to the operating condition of the engine. doing. The engine control unit may forcibly prohibit drive control or stop control of a specific actuator as appropriate in order to protect the engine from an emergency state such as overheating. Therefore, even if the specific actuator does not appropriately respond to the test signal sent from the tester and control for diagnosis is impossible, control of the actuator is already prohibited from the engine control unit as described above. In some cases, it may not be said that the actuator itself has failed, and as a result, erroneous diagnosis may be made.

The present invention has been made in view of the above background, and an object of the present invention is to provide a failure diagnosis device for a vehicle that can prevent erroneous diagnosis of a failure diagnosis when an actuator is in a prohibited state.

<< Means for Solving the Problems >> In order to achieve the above object, the present invention connects a tester for transmitting a test signal for failure diagnosis of the vehicle-mounted electronic control system to a control unit for controlling the vehicle-mounted electronic control system. The vehicle failure diagnosis device comprises: a detection unit for detecting a control prohibition state of the on-vehicle electronic control system by the control unit; and a notification unit for notifying the detection result on the tester side. .

In the control prohibition state, predetermined control in the on-vehicle electronic control system is forcibly prohibited in order to protect various parts of the vehicle such as the engine from an emergency state.

<Operation> With the above configuration, predetermined control in the vehicle-mounted electronic control system is forcibly prohibited in order to protect the vehicle-mounted electronic control system from the control-prohibited state by the detection means, for example, to protect each part of the vehicle such as the engine from an emergency state. Is detected, and the detection result is reported on the tester side by the reporting means. Therefore, during failure diagnosis, whether the in-vehicle electronic control system does not respond to the test signal and becomes uncontrollable is due to a failure in the in-vehicle electronic control system, or the in-vehicle electronic control It is possible to determine whether the system is in the control prohibited state.

<< 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 a control unit.

The tester 1 is connected to the ECU 2 by a serial communication path 4 via a serial interface 3 and is capable of transmitting a test signal and receiving various information such as a response to the test signal. Information is transmitted and received.

The ECU 2 is connected to a large number of sensors 5 and actuators 6 arranged at various parts of the engine (not shown). The sensors 5 and the actuators 6 are integrated by the ECU 2 to constitute an electronic control system, and the engine 2 is controlled according to a predetermined procedure. Are controlled.

At the time of failure diagnosis, a test signal such as a drive or stop command for various actuators 6 is transmitted from the tester 1 to the ECU 2 and detection of various sensors 5 indicating the operation status of the electronic control system in response to these test signals. Responses such as signals are sent back from ECU2 to Tester 1,
As described above, the failure of the electronic control system is diagnosed by transmitting and receiving information to and from each other by bidirectional communication.

FIG. 2 is a block diagram showing a part according to the present invention of the vehicle failure diagnostic device according to the present invention shown in FIG.

The present invention is basically based on a control unit (in this embodiment, a control unit for controlling an on-vehicle electronic control system (actuators 61 to 6X)).
In a vehicle failure diagnosis device configured by connecting a tester 1 for transmitting a test signal for failure diagnosis of the vehicle-mounted electronic control systems 61 to 6X to the ECU 2), a vehicle-mounted electronic control system 61 to 6X by the control unit 2 is provided. And a notifying means for notifying the detection result on the tester 1 side. The detecting means and the notifying means are provided by software programs of a computer constituting the tester 1 and the ECU 2 respectively. It is realized by.

Control prohibition status of various actuators 61 to 6X
When an operation or stop control command is issued to the actuators 61 to 6X, the actuators 61 to 6X are first in the memory 20 in a control-prohibited state (ON ) Or not (OFF).
It is confirmed.

The prohibition of control of the actuators 61 to 6X is a function for protecting various parts of the vehicle from an emergency state such as engine protection as described above, and the control prohibition state is performed based on various information on the operating state of the engine obtained from the sensor 5. Is determined, and the determination is made on the ECU 2 side (determination means 2).
1) or the tester 1 side (judgment means 10), or both, by monitoring the detection result from the sensor 5 or the like.

When the test signal 11 for the actuators 61 to 6X is sent from the tester 1 to the ECU 2, the ECU 20 searches the memory 20. If the actuators 61 to 6X are in the control prohibited state, the prohibition state signal is output to the tester. It is returned to 1 side. Then, on the tester 1 side, the display unit 12 displays that the actuators 61 to 6X are in the control prohibition state by the prohibition state signal. On the other hand, when the actuators 61 to 6X involved in the search are not in the control prohibited state, the operation of the actuators 61 to 6X is controlled based on the test signal 11, and a control start signal is returned to the tester 1 side.

That is, according to such a configuration, the control means detects the control inhibition state of the various actuators 61 to 6X,
The detection result is notified on the tester 1 side. Therefore, at the time of failure diagnosis, whether the uncontrollable state in which the actuators 61 to 6X do not respond to the test signal 11 is due to a failure in the actuators 61 to 6X and the control system side,
It is possible to determine whether the actuators 61 to 6X are in the control prohibited state. Thereby, erroneous recognition can be prevented. In addition, the burden on service personnel operating the tester 1 can be reduced, and operability can be improved.

<< 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 detection means controls the on-vehicle electronic control system from the control-prohibited state, for example, the engine and other parts of the vehicle from the emergency state. For protection, a state in which predetermined control in the on-vehicle electronic control system is forcibly prohibited is detected, and the detection result is reported on the tester side by the reporting means. Therefore, during failure diagnosis, whether the in-vehicle electronic control system does not respond to the test signal and becomes uncontrollable is due to a failure in the in-vehicle electronic control system, or the in-vehicle electronic control It is possible to determine whether the system is in the control-prohibited state, thereby preventing erroneous recognition.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a vehicle failure diagnostic device according to the present invention, and FIG. 2 is a configuration diagram showing a part of the vehicle failure diagnostic device according to the present invention shown in FIG. 1 according to the present invention. 1. Tester 2. Control unit (ECU) 61-6X ... On-board electronic control system (actuator)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) G01M 17/00-17/10 G01M 15/00

Claims (2)

(57) [Claims] An in-vehicle failure diagnosis apparatus comprising a control unit for controlling an on-vehicle electronic control system and a tester for transmitting a test signal for failure diagnosis of the on-vehicle electronic control system. A failure diagnosis device for a vehicle, comprising: detection means for detecting a control prohibition state of the on-vehicle electronic control system by the application unit; and notification means for notifying the detection result on the tester side. 2. A predetermined control in the on-vehicle electronic control system is forcibly prohibited in the control prohibition state in order to protect various parts of the vehicle such as an engine from an emergency state. Vehicle failure diagnosis device.