JP2000018082A - Vehicular trouble diagnostic system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a data erasing terminal or the like in the case where an EEPROM is used. SOLUTION: This vehicular trouble diagnostic system 10 is equipped with a diag-connector 12, an EEPROM 14 and a CPU 16 or the like. A function of the CPU 16 is to erase trouble data (b) stored in the EEPROM 14 whenever a data erasing signal (c) is inputted from the diag-connector 12. In the case where the trouble data (b) of the EEPROM 14 are erased, the existing diag- connector 12 for outputting the trouble data (b) is used whereby any data erasing terminals and the like can be made into disuse.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic control system for a vehicle, in which when a failure occurs in a sensor, an actuator, a wire harness or the like, a CPU diagnoses the failure location and stores and displays the failure. The present invention relates to a failure diagnosis device.

[0002]

2. Description of the Related Art In an ECU (Electronic Control Unit), an input signal to a CPU may be abnormal, or a combination of these input signals may be abnormal. in this case,
The CPU diagnoses a failure in the sensor, the actuator, the wire harness, or the like, and turns on a warning lamp to notify the driver. The contents of the failure diagnosis are stored in a memory backed up by a battery so that the contents of the failure diagnosis are not erased even after the ignition key is turned off.

[0003]

In recent years, an EEPROM (Electrically Erasable) has been used as a memory capable of retaining the contents of failure diagnosis even when power supply from a battery is lost.
Programmable ROM) has come to be used. However, when an EEPROM is used, an input terminal for receiving a signal for erasing data, a connector for externally inputting the signal, and the like are required. Therefore, an increase in the number of parts has led to an increase in size, an increase in cost, and a complicated assembly process.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an EEPROM.
An object of the present invention is to provide a vehicle failure diagnosis device which does not cause an increase in the number of parts even when using the device.

[0005]

According to the present invention, there is provided a failure diagnosis apparatus for a vehicle, comprising: a diagnostic connector; an EEPROM;
U. This CPU has the following functions: . Failure data is input from a sensor or the like, and the failure data is stored in an EEPROM. . When a data output signal is input from the diagnostic connector, EEPRO
The failure data stored in M is output. . When a data erase signal is input from the diagnostic connector, the EEPR
Erase the fault data stored in the OM. This function is a feature of the present invention. The data erase signal is
It can be constituted by a predetermined number of repetitions of short-circuiting and opening of the diagnostic connector, and a short-circuiting time of the diagnostic connector for a certain time or more.

[0006] The failure data from the sensors and the like is stored in the EEPROM by the CPU. Also, EEPRO
When the operator wants to know the failure data stored in the M, the operator outputs a data output signal using the diagnostic connector to the CPU.
Output to Up to this point, it is the same as the conventional technology. In the present invention, when it is desired to erase the failure data stored in the EEPROM, the operator outputs a data erase signal to the CPU using the diagnostic connector. Thus, EE
When erasing the failure data stored in the PROM, the existing diagnostic connector is used, so that the number of parts does not increase.

[0007]

FIG. 1 is a block diagram showing a first embodiment of a vehicle failure diagnosis apparatus according to the present invention. Hereinafter, description will be made based on this drawing.

[0008] The vehicle failure diagnosis apparatus 10 of the present embodiment comprises:
Diag connector 12, EEPROM 14, CPU 16
Etc. are provided. The CPU 16 is provided in the ECU 18 and also functions as a control CPU. CPU1
The functions of the vehicle failure diagnosis device 10 described in 6 below are realized by a computer program, and are particularly characterized. . Failure data b is input from a sensor (not shown) or the like, and the failure data b is stored in an EEPROM.
14 is stored. . When the data output signal a is input from the diagnostic connector 12, the failure data b stored in the EEPROM 14 is output. . When the data erase signal c is input from the diagnostic connector 12, the EEPRO
The failure data b stored in M14 is deleted.

An input diagnostic connector 12 is connected to an input port Pi of the CPU 16 via an input interface 20i and an input terminal 18i. CPU1
6 is connected to an output diagnostic connector 22 via an output interface 20o and an output terminal 18o. A short wire 24 can be connected to the diagnostic connector 12, and a warning lamp 26 can be connected to the diagnostic connector 22.

The diagnostic connector 12 has a ground terminal GND.
And an input terminal DNS. The ground terminal GND is grounded, and the input terminal DNS is connected to the input terminal 18i. The short wire 24 is just a conductor. Therefore, the short wire 24 is connected to the diagnostic connector 12.
Is connected, that is, when the diagnostic connector 12 is in a short-circuit state, an L (low) level signal is input to the input terminal 18i. On the other hand, when the short wire 24 is not connected to the diagnostic connector 12, that is, when the diagnostic connector 12 is open, an H (high) level signal is input to the input terminal 18i. The data output signal a and the data erasure signal c can be configured so as not to be confused by the CPU 16 by using the L level signal and the H level signal.

The diagnostic connector 22 has a ground terminal GND.
And an output terminal DNL. The ground terminal GND is grounded, and the output terminal DNL is connected to the output terminal 18o. An H-level signal and an L-level signal are output from the output terminal 18o. The failure data b output to the diagnostic connector 22 corresponds to, for example, 2 composed of an H level signal and an L level signal corresponding to the content of the failure.
Is the decimal code of the digit. Therefore, the warning lamp 26 connected to the diagnostic connector 22 blinks according to the failure data b.

FIG. 2 is a time chart showing an example of the operation of the vehicle failure diagnosis device 10. Hereinafter, FIGS. 1 and 2
The operation of the vehicle failure diagnosis device 10 will be described based on the following.

FIGS. 2A and 2B show the EEPROM 1
The operator uses the diagnostic connector 12 to output the data output signal a to C
This is the case of outputting to PU16. The data output signal a is
It consists of a fixed short circuit time Tx of the diagnostic connector 12.

First, when the worker connects the short wire 24 to the diagnostic connector 12, the input terminal DNS has L
A level signal is input (time t ₀ ). When the fixed short-circuit time Tx has elapsed, the CPU 16 determines that the data output signal a has been input (time t ₁ ). And CP
U16 outputs the failure data b stored in the EEPROM 14. Then, the warning lamp 26 connected to the output terminal DNL blinks according to the coded failure data b. Thereby, the operator can know the details of the failure. Subsequently, when the worker detaches the short wire 24 from the diagnostic connector 12, an H level signal is input to the input terminal DNS. At this time, the CPU 16
Determines that the data output signal a is no longer input, and stops outputting the failure data b (time t ₂ ).

FIG. 2C shows a case where an operator outputs a data erasure signal c to the CPU 16 using the diagnostic connector 12 in order to erase the failure data b stored in the EEPROM 14. The data erasing signal c is composed of five consecutive short circuits # 1 to # 5 of the diagnostic connector 12.
H level signal time and L which constitute short circuit number # 1 to # 5
Level signal period Ty ₁ ~Ty ₉ are each shorter than a predetermined short time Tx, and the total time Tm is required to be shorter than the maximum total time (not shown). These conditions are set in order to avoid confusion between the data erasing signal c and the data output signal a and to prevent malfunction due to chattering or erroneous operation.

First, when the worker connects the short wire 24 to the diagnostic connector 12, the input terminal DNS has L
A level signal is input (time t ₀ ). Subsequently, the operator detaches the short wire 24 from the diagnostic connector 12 within a certain short-circuit time Tx, and likewise
The connection and disconnection of 4 are repeated five times within the maximum total time.
As a result, the CPU 16 determines that the data erasure signal c has been input, and erases the failure data b stored in the EEPROM 14 (time t ₃ ).

FIG. 3 is a configuration diagram showing a second embodiment of the vehicle failure diagnosis apparatus according to the present invention. Hereinafter, description will be made based on this drawing. However, the same parts as those in FIG.

In the vehicle failure diagnosis apparatus 30 of the present embodiment, the input / output terminal 18io, the diagnostic connector 12, and the CPU 32 are different from those of the first embodiment in order to further reduce the number of parts. The input / output terminal 18io is an input terminal 18i (FIG. 1) and an output terminal 18o (FIG. 1) in the first embodiment.
And are shared. The diagnostic connector 12
Input Diag Connector 12 in First Embodiment
(FIG. 1) and an output diagnostic connector 22 (FIG. 1). The CPU 32 changes the computer program of the CPU 16 (FIG. 1) in the first embodiment in accordance with the sharing.

FIG. 4 is a time chart showing an example of the operation of the vehicle failure diagnosis device 30. Hereinafter, FIGS. 3 and 4
The operation of the vehicle failure diagnosis device 30 will be described based on FIG.

FIG. 4A shows a case where an operator uses the diagnostic connector 12 to output a data output signal a to the CPU 32 in order to know the failure data b stored in the EEPROM 14. The data output signal a has an open state longer than the erase operation waiting time (not shown) of the diagnostic connector 12. This open state means that the diagnostic connector 1
In addition to the state in which nothing is connected to 2, the state includes the state in which the warning lamp 26 is connected to the diagnostic connector 12, in other words, the state in which the output side has a high resistance value.

First, when the worker has nothing connected to the diagnostic connector 12, an H level signal is input to the input / output terminal DN. When the maximum erasing operation waiting time (not shown) elapses, the CPU 16 outputs the data output signal a.
Is determined to have been entered. Then, the CPU 16
The failure data b stored in the OM 14 is output. At this time, when the operator connects the warning lamp 26 to the input / output terminal DN, the warning lamp 26 blinks according to the coded failure data b. Thereby, the operator can know the details of the failure.

FIG. 4B shows a case where an operator outputs a data erasure signal c to the CPU 32 using the diagnostic connector 12 in order to erase the failure data b stored in the EEPROM 14. The data erasure signal c includes a short-circuit time T ₄ longer than the input confirmation time (not shown) of the diagnostic connector 12, an open time T ₅ within the maximum erasure operation waiting time, and the number of consecutive short-circuits # 1 to five of the diagnostic connector 12 # 5. H-level signal time and the L-level signal time Ty ₁ ~Ty ₉ constituting the number of short circuits # 1 to # 5, respectively predetermined time range (e.g. 0.5S～2.0S) within and total time Tm
Must be less than the maximum total time (not shown). Further, the code cycle T ₁ and the digit interval T shown in FIG.
₂ , the code interval T ₃ and the short circuit time T ₄ shown in FIG.
Is such that T ₄ > T ₃ > T ₂ > T ₁ . These conditions are set in order to avoid confusion between the data erasing signal c and the data output signal a and to prevent malfunction due to chattering or erroneous operation.

First, when the operator connects the short wire 24 to the diagnostic connector 12 while the failure data b is being output, the input / output terminal DN goes to the L level regardless of the output state (time t ₀ ). . When the L-level state continues for the input determination time or more, the CPU 32 stops outputting the failure data b. Subsequently, the operator disconnects the short wire 24 from the diagnostic connector 12 within the maximum erasing operation waiting time (time t ₀ ), and similarly repeats connection and disconnection of the short wire 24 five times within the maximum total time. As a result, the CPU 16 outputs the data erase signal c.
Is input, and the failure data b stored in the EEPROM 14 is erased (time t ₂ ). T ₆ is erased execution time.

[0024]

According to the vehicle failure diagnosis apparatus of the present invention, when erasing the failure data stored in the EEPROM, the existing diagnostic connector for outputting the failure data is used, and the data erasure is performed. This can eliminate the need for the terminals and the like, thereby suppressing an increase in the number of components. Therefore, downsizing, cost reduction, simplification of an assembling process, and the like can be achieved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a vehicle failure diagnosis device according to the present invention.

2 is a time chart showing an example of the operation of the vehicle failure diagnosis apparatus of FIG. 1; FIGS. 2 [1] and [2] show a case where an operator outputs a data output signal to a CPU using a diagnostic connector; FIG. 2 [3] shows a case where the operator outputs a data erase signal to the CPU using the diagnostic connector.

FIG. 3 is a configuration diagram showing a second embodiment of the vehicle failure diagnosis device according to the present invention.

4 is a time chart showing an example of the operation of the vehicle failure diagnosis apparatus of FIG. 3; FIG. 4 [1] shows a case where an operator outputs a data output signal to a CPU using a diagnostic connector; 4 [2] is a case where the operator outputs a data erase signal to the CPU using the diagnostic connector.

[Explanation of symbols]

 10, 30 Vehicle failure diagnostic device 12 Diag connector 14 EEPROM 16, 32 CPU a Data output signal b Failure data c Data erasure signal

Claims (3)

[Claims] 1. A diagnostic connector, an EEPROM,
When failure data is input from a sensor or the like and the failure data is stored in the EEPROM, and when a data output signal is input from the diagnostic connector, the EEPROM
And a CPU that outputs the failure data stored in the EEPROM. When the CPU inputs a data erasure signal from the diagnostic connector, the CPU erases the failure data stored in the EEPROM. A failure diagnosis device for a vehicle, characterized in that: 2. The method according to claim 1, wherein the data erasing signal comprises a predetermined number of repetitions of short-circuiting and opening of the diagnostic connector.
The vehicle fault diagnosis device according to claim 1. 3. The fault diagnosis device for a vehicle according to claim 1, wherein the data erasure signal is a short-circuit time of the diagnostic connector that is equal to or longer than a predetermined value.