JPH0726682Y2 - Failure diagnosis device for automobile electronic system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a failure diagnostic device for an automobile electronic system.

(Prior Art) In an electronic system for automobiles, a diagnostic function is provided for a failure (circuit disconnection or short circuit of the circuit or a sensor failure occupies most) that occurs in the signal system to the control unit. Since only the presence or absence of a fault is determined from the signal level at the input part of the unit or the calculation result of the CPU, it is possible to diagnose only where the fault system is.

Therefore, when such a failure occurs, it is necessary to identify the failure portion in more detail and perform repair, and therefore a tester is used (Japanese Patent Laid-Open No. 64-83434 and 64-8).
(See Japanese Patent No. 3435).

(Problems to be solved by the invention) By the way, in the conventional case, the output of the tester has to be adjusted (setting of the signal waveform) every time the signal system to be diagnosed changes, and the work of searching for the faulty part must be performed. Be extremely complicated,
There is also a problem that specialized knowledge is required.

An object of the present invention is to provide a diagnostic device capable of facilitating such complicated fault search.

(Means for Solving the Problems) Therefore, the present invention has a pseudo signal output terminal and a voltage / pulse input terminal as shown in FIG. 1, and selects a pseudo signal at the same level as various input signals to the control unit. Generated pseudo signal generation means, an input operation means for instructing the pseudo signal generation means to generate a pseudo signal of a signal system to be diagnosed, and a failure search procedure on the screen based on the signal from the input operation means. Search procedure display means for displaying, failure determination means for comparing the measured value of the voltage / pulse input terminal with the output level of the pseudo signal to determine the presence / absence of a failure, and replacement of a failed component based on the signal from the failure determination means. A repair procedure display means for displaying the procedure on the screen is provided.

(Operation) With this configuration, as long as the signal system to be diagnosed is designated by the input operation means, all that is required is to proceed with the work according to the search procedure and repair procedure displayed on the screen. Even if it is changed, it is not necessary to set the signal waveform as in the conventional tester, and therefore even a person without so much specialized knowledge can easily identify and repair the failure part.

(Embodiment) In FIG. 2, reference numeral 1 is an input operation section having a screen 2, and 3 is a pseudo signal generator for generating a pseudo signal of the same level as a sensor signal of a designated signal system by touch button operation of the input operation section 1. , The input operation unit 1 has a voltage / pulse input terminal 4
However, the pseudo signal generator 3 is provided with an output terminal 5.

Although not shown in the input operation section 1, a search procedure display circuit for displaying a failure search procedure for a designated signal system by touch button operation on the screen 2 and a voltage / pulse input terminal 4
A failure judgment circuit for judging the presence or absence of a failure by comparing the measured value of 1 with the output level of the pseudo signal, and a repair procedure display circuit for displaying on the screen 2 the replacement procedure of the failed component based on the judgment result are stored.

FIG. 3 is a flowchart explaining an example of the diagnostic operation.
When the fault system to be diagnosed is designated by the touch button operation of the input operation unit 1, the fault search procedure for the designated signal system is first displayed on the screen 2.

As a result, as shown in FIG. 4, when the pseudo signal output terminal 5 is connected to the connector 7 which is removed from the sensor 6 and the voltage / pulse terminal 4 is connected to the connector 10 on the input side of the control unit 9 of the harness 8, the diagnosis is OK. Is determined, a pseudo signal of the same level as the designated signal system is output, and at the same time, measurement at the voltage / pulse input terminal 4 is started.

If the measured value at the voltage / pulse input terminal 4 is abnormal, the harness is determined to be defective, and the procedure for repairing the harness is determined. If the measured value is normal, the sensor is determined to be defective and the sensor is replaced. Each procedure is displayed on screen 2.

With such a configuration, at the time of starting the diagnosis of the fault system, the operator only needs to specify the signal system to be diagnosed by the touch button operation of the input operation unit 1, and thereafter the work is performed according to the procedure displayed on the screen 2. All you have to do is proceed. In this case, since the pseudo signal generator 3 selectively generates a pseudo signal having the same level as the sensor signals of various systems, various testers are prepared as in the conventional case even if the diagnosis target is changed, or each signal system is different. It is not necessary to set the signal waveform, and therefore, even a person who does not have so much specialized knowledge can easily identify and repair the failure part.

(Effects of the Invention) In short, according to the present invention, the pseudo signal generating means, which has the pseudo signal output terminal and the voltage / pulse input terminal, selectively generates the pseudo signal of the same level as various input signals to the control unit. An input operation means for instructing the pseudo signal generation means to generate a pseudo signal of a signal system to be diagnosed, and a search procedure display means for displaying a failure search procedure on the screen based on a signal from the input operation means, Repair by comparing the measured value of the voltage / pulse input terminal with the output level of the pseudo signal to determine the presence / absence of a failure, and displaying the replacement part replacement procedure on the screen based on the signal from the failure determination means. Since the procedure display means is provided, it is possible to easily identify and repair the faulty part without making a mistake in the procedure even if the person does not have specialized knowledge. Is obtained.

[Brief description of drawings]

FIG. 1 is a diagram corresponding to the claims of the present invention, FIG. 2 is a configuration diagram showing the same embodiment, FIG. 3 is a flow chart explaining an example of a diagnostic operation, and FIG. 4 is an example of a usage state of the device. FIG. 1 ... Input operation part, 2 ... Screen, 3 ... Pseudo signal generator, 4 ...
Voltage / pulse input terminal, 5 ... Pseudo signal output terminal.

Claims (1)

[Scope of utility model registration request] 1. A pseudo signal generating means for selectively generating a pseudo signal having the same level as various input signals to a control unit, comprising a pseudo signal output terminal and a voltage / pulse input terminal, and a diagnosis for the pseudo signal generating means. Input operation means for instructing the generation of a pseudo signal of the target signal system, search procedure display means for displaying a failure search procedure on the screen based on the signal from the input operation means, and voltage / pulse input terminal measurement values Is provided with a failure determination means for comparing the output level of the pseudo signal to determine the presence or absence of a failure, and a repair procedure display means for displaying the replacement procedure of the failed component on the screen based on the signal from the failure determination means. A failure diagnosis device for electronic vehicle systems.