JP2002002419A - Electronic control unit for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic control unit(ECU) allowing specifying of contents (cause) of a failure (abnormality) of the ECU, as for the ECU judged as the failure by a dealer and sent to a vehicle maker or an ECU maker. SOLUTION: A first failure code (a main failure code) for specifying a failure portion is prepared when the failure occurs in any one of the ECU 10 and external equipments (a sensor 16 and an actuator 18). A second failure code (sub-failure code) for specifying the failure content is prepared when the failure occurs in the ECU 10. The failure codes are stored in storage means (a memory 22, a main memory 12a and a sub-memory 20a) and can be read.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle electronic control unit, and more particularly, to a vehicle electronic control unit which is mounted on a vehicle and, when a failure occurs in the vehicle electronic control unit and an external device connected thereto, the failure occurs. The present invention relates to a vehicle electronic control unit capable of storing and outputting a location and a failure content.

[0002]

2. Description of the Related Art A conventional vehicle electronic control unit will be described with reference to FIG.

FIG. 6 is an explanatory block diagram for explaining a configuration of a vehicle electronic control unit (hereinafter referred to as “ECU”) 10 according to the prior art. The ECU 10 is mounted on a vehicle (not shown).

[0004] The ECU 10 according to the prior art includes a main CP.
The main CPU 12 is connected to external devices such as a sensor (for example, a speed sensor) 16 and an actuator (for example, a 4WD actuator) 18 via an input / output circuit 14, and outputs an output signal of the sensor 16 and drives the actuator 18. Transmission and reception of signals and the like are performed.

The main CPU 12 includes a main CPU 12
And a sub CPU 20 for monitoring the operation thereof. Each CPU is supplied with an operating voltage (for example, about 5 [V]) from a power supply (not shown vehicle-mounted battery). Also, the main CPU 1
2 is a memory 2 that can communicate with the main CPU 12.
2 are connected to perform data writing / reading.

When a failure occurs in the ECU 10 constructed as described above or in a connected external device,
The main CPU 12 stores a code (fault code) for specifying a fault location in a built-in memory (not shown) of the main or sub CPU or the memory 22, and a warning lamp connected via the input / output circuit 14. 24 (shown as "W / L" in the figure) is turned on to warn the driver (user).

When the driver receiving the warning from the warning lamp 24 brings the vehicle to a dealer, a diagnostic device (external diagnostic device) 26 such as a digital circuit tester is connected to the dealer via a harness 28. ECU1
Connected to 0. The fault code stored in the memory inside and outside the CPU is read out by the diagnostic device 26, and the fault location (whether a fault has occurred in the ECU 10 or a mechanical fault) is specified.

[0008] As a result of this specific result, the dealer has the "EC
If it is determined that the "U failure", the ECU 10 is sent to a vehicle maker or an ECU maker, and in the case of a vehicle maker or an ECU maker, the cause of the ECU failure (abnormality) is analyzed.

[0009]

As described above, the ECU sent to the manufacturer has only "ECU failure" as information (failure code) relating to the failure.
There is a possibility that a long time and a large number of man-hours are required to identify which part of the inside is the cause of the failure (abnormality), that is, to identify the content of the failure.

In order to eliminate such inconvenience, as described in Japanese Patent Application Laid-Open No. 7-218391, when erasing a failure code of an ECU at a dealer, the failure code is copied to a backup memory. Thus, a technique has been proposed in which a vehicle manufacturer or an ECU manufacturer facilitates identification of a failure location.

However, in the technique described in Japanese Patent Application Laid-Open No. Hei 7-218391, only the location of the failure is still specified, so that the manufacturer of the vehicle or ECU specifies the content of the failure. Therefore, there is a possibility that a long time and a large number of man-hours are required.

[0012] Accordingly, the present invention relates to a "ECU"
It is an object of the present invention to provide an ECU (vehicle electronic control unit) that can determine the cause of a failure (abnormality) of an ECU sent to a vehicle maker or an ECU maker after being judged as "abnormal". .

[0013]

According to an aspect of the present invention, there is provided a vehicle having at least one CPU, a memory, and an input / output circuit. A vehicle electronic control unit (ECU) connected to an external device via the input / output circuit,
When a failure occurs in any of the vehicle electronic control unit and the external device, a first failure code creating unit that creates a first failure code specifying the location of the failure and stores the first failure code in the memory. A second fault code generating means for generating a second fault code specifying the content of the fault when the error occurs in the vehicle electronic control unit and storing the second fault code in the memory; It is configured to include a failure code output unit that outputs the first failure code and the second failure code.

When a failure occurs in one of the ECU and the external device, in addition to creating a first failure code (main failure code) for specifying the location of the failure, when a failure occurs in the ECU, the failure occurs. A second failure code that specifies the content of the ECU, that is, a sub-failure code corresponding to the detailed location of the ECU failure is created and configured to be readable. It is easy to identify the cause of the failure (abnormality).

Further, in the present invention, the failure code output means outputs at least the stored second failure code as a pulse train.

Since the second fault code is configured to be output as a pulse train, it is not necessary to add a special circuit for reading the fault code. ) Can be identified.

According to a third aspect of the present invention, the memory includes a RAM having a backup power supply and an E ² PRO.
M.

The failure code, in particular, the second failure code may be a RAM or an E ² PR with a backup power supply.
Since it is configured to be stored in a memory such as the OM, the vehicle manufacturer or the ECU manufacturer can more reliably read the second failure code.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an ECU (vehicle electronic control unit) according to one embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is an explanatory block diagram for explaining a configuration of an ECU according to one embodiment of the present invention. Since the configuration of the ECU according to the present embodiment is substantially the same as the configuration of the ECU according to the related art, the same components are denoted by the same reference numerals, and detailed description thereof will be omitted.

The following is a description focusing on the differences.
First, a main memory 12 including a RAM having a backup power supply (not shown) is provided inside the main CPU 12.
a is provided. When a failure occurs in the internal device of the ECU 10 or in a connected external device, the main CPU 12 stores a main failure code (first failure code) for specifying a failure location in the memory 22, and the input / output circuit 1.
4 connected to the warning lamp ("W /
L) is turned on, and a warning is issued to the driver.

In this embodiment, the failure is detected by the ECU 1
If the failure has occurred at 0, a sub-failure code (second failure code) in which the failure location or failure content (failure operation) of the ECU 10 is stored in the main memory 12a. Note that the stored sub failure code is output as a pulse train from an output port A provided in the main CPU 12.

Next, with reference to FIG. 2 and FIG. 3, a process of specifying a failure and specifying a cause of the failure (when the ECU fails) according to this embodiment will be described.

FIG. 2 is a flowchart showing a process of creating and storing a fault code according to the fault (location and content) started by the ECU 10 when a fault occurs in the internal device of the ECU 10 or a connected external device. is there. Main CP
When U12 detects the above-described failure, first, at S10, a warning lamp is turned on to warn the driver.

Next, the program proceeds to S12, in which a fault location (a fault occurring in the ECU 10, or a sensor 16,
A main failure code corresponding to a mechanical failure occurring in the actuator 18 or the like) is created and stored in the memory 22.

Next, the program proceeds to S14, in which it is determined whether the created main failure code is a failure in the ECU 10. If affirmative in S14, the program proceeds to S
In step 16, what kind of fault has occurred in which part of the ECU 10, that is, the content of the fault is specified, and a sub fault code corresponding to the fault content is created.
2a and the program ends. When the result in S14 is NO, the program skips S16 and ends the processing.

When the vehicle that has undergone the above-described processing is brought into a dealer, a mechanic or the like at the dealer installs a diagnostic device (external diagnostic device) 26 such as a digital circuit tester.
Connected to the ECU 10 via the harness 28. Diagnostic machine 2
In step 6, the main failure code stored in the memory 22 is read, and the failure location (whether the failure has occurred in the ECU 10 or the mechanical failure) is specified.

More specifically, the monitor of the diagnostic device 26
For example, it is configured to display a two-digit numerical value, and the maintenance staff at the dealer determines from the displayed numerical value that the failure that has occurred this time is a failure that has occurred in the ECU 10 or a mechanical failure (an abnormal operation of the actuator 18). , The output signal of the sensor 16 is abnormal, etc.).

If the failure has occurred in the ECU 10, the ECU 10 is removed from the vehicle and sent to a vehicle manufacturer or an ECU manufacturer.
If the failure has occurred in a location other than the above, a measure corresponding to the failure location is taken.

The main failure code stored in the memory 22 is deleted when the ECU 10 is removed from the vehicle. However, since the main memory 12a is a RAM having a backup power supply as described above, Can be read out by the vehicle manufacturer or the ECU manufacturer without being erased.

FIG. 3 is a flow chart showing an output process when the sub failure code is read from the main memory 12a. When reading the sub failure code, the EC
A predetermined power supply (not shown) is connected to U10 to supply an operating voltage, and an oscilloscope (external diagnostic device) and a monitor (both not shown) are connected to the output port A.

At this time, predetermined terminals are short-circuited (connected) at the vehicle manufacturer or the ECU manufacturer. This short circuit (connection) serves as a switch for outputting a pulse train from the main memory 12a, that is, for reading out the contents of the failure. This program is connected for 20 msec when the operating voltage is supplied as described above.
It is executed every time.

When the description of the flow chart is started, it is first determined in S100 whether or not the ECU 10 has failed. This is performed by confirming whether or not a sub failure code is stored in the main memory 12a. S1
When denied at 00, the program ends and
When the result is affirmative, the process proceeds to S102, and it is determined whether or not the specific terminal is connected.

If the result in S102 is negative, the output of the sub-failure code is not requested, so that the subsequent program is skipped and the program is terminated.
When the result in S2 is affirmative, the program proceeds to S104, in which the sub failure code created and stored in S16 of the flow chart of FIG.
It is determined whether or not the output mode A pulse is included.

Hereinafter, the sub failure code and the output mode A will be described.
Will be described with reference to FIG.

In this embodiment, the output sub-failure codes are set from # 1 to # 99, and
The pulse train corresponding to the sub failure code is output. The pulse train to be output includes an A pattern (: a pulse having a period α), a B pattern (: a pulse having a period β), and a C pattern (: a length γ) schematically shown in FIG.
Low-level signals).

In this embodiment, the combination of the A to C patterns is such that the tens place is the A pattern, the one place is the B pattern, and then the C pattern is added. For example, the output pattern (and output order) when the sub failure code is # 12 is a pulse train of A pattern × 1 time + B pattern × 2 times + C pattern as shown in FIG. As described above, the processing in the flowchart of FIG.
This pulse train is repeatedly output because it is executed every time.

Returning to the description of the flowchart of FIG. 3 based on the above, if the result in S104 is affirmative, the program proceeds to S
Proceeding to 106, the output of the A pattern is performed. Next, the program proceeds to S108, where S in the flowchart of FIG.
It is determined whether or not the sub-failure code created and stored in step 16 includes an output mode B pulse.

The flow of S108 and S110 is as follows.
Since the processing is similar to the flow of S104 and S106, the description is omitted. After the output of the B pattern is completed in S110, the process proceeds to S112, and the output of the C pattern (low level signal) is performed.

By executing the processing shown in the flow chart of FIG. 3, a pulse train corresponding to the sub failure code is displayed on the monitor connected to the oscilloscope.
For vehicle manufacturers or ECU manufacturers, E
The cause of the failure (abnormality) of the CU can be specified.

Further, since the output sub-failure code is composed of a pulse train, it is not necessary to add a special circuit for reading the failure code, and a simple configuration using an oscilloscope or the like allows the ECU failure (abnormality) to be detected. The cause can be identified.

Further, since the second failure code is configured to be stored in the main memory 12a composed of a RAM provided with a backup power supply, the vehicle manufacturer or the ECU may provide the second failure code.
The manufacturer can more reliably read the second failure code.

Next, an electronic control unit for a vehicle according to a second embodiment of the present invention will be described. Before starting the description of the second embodiment, the main CPU of FIG.
The operation of the sub CPU 20 and the sub CPU 20 will be described briefly.

As mentioned above, the sub CPU 20
It is communicably connected to the PU 12 and monitors its operation. When the operation of the main CPU 12 is abnormal, that is, when the main CPU 12 malfunctions, the operation of the main CPU 12 is stopped while the sub CPU 20 Is preferably reset.

However, when the main CPU 12 is reset, the main memory 1 in the first embodiment is reset.
2a is also reset, and the main CPU
When an abnormality occurs in the ECU 12, it is complicated to specify the failure content of the ECU 10. In view of this, in the second embodiment, an R CPU having a backup power supply in the sub CPU 20 is provided.
A sub memory 20a made of AM is provided, and a sub failure code is stored in the sub memory 20a. The sub CPU 20 is configured to include an output port B for reading a sub failure code.

The operation of the sub memory 20a is not different from that of the main memory 12a, except that the sub memory 20a is provided at a different location. Since the sub CPU 20 is not reset even if the main CPU 12 malfunctions, the contents of the sub memory 20a are not erased.

Therefore, in addition to the effects of the first embodiment,
Even if the main CPU 12 malfunctions, the sub failure code can be stored. That is, the safety of control by the ECU 10 can be increased.

[0048] In the first and second embodiments described above, the main memory 12a and the sub memory 20a is has been configured such that a RAM with a backup power source is not limited thereto, from the memory such as E ² PROM You may make it.

As described above, according to the embodiment of the present invention, at least one CPU (main CPU 12, sub CPU 20) and a memory (memory 22, main memory 12a, sub memory 20a) are mounted on the vehicle. And an input / output circuit (output ports A and B), and a vehicle electronic control unit (ECU) connected to external devices (sensors 16 and actuators 18) via the input / output circuit.
In 10), when a failure occurs in any of the vehicle electronic control unit and the external device, a first failure code (main failure code) for specifying the failure location is created and stored in the memory. Failure code creating means (S12 in the flow chart of FIG. 2), when the failure occurs in the vehicle electronic control unit, creates a second failure code (sub-failure code) for specifying the content of the failure, and When connected to the second failure code creating means (S14, S16 in the flow chart of FIG. 2) to be stored in the memory and an external diagnostic device (diagnostic device 26, oscilloscope), the stored first failure code and the second failure code are connected. Fault code output means (harness 28,
Output ports A, B).

The fault code output means outputs at least the stored second fault code as a pulse train (FIG. 4).
(Combination of patterns A to C) (S106, S110, S112 in the flowchart of FIG. 3).
It was configured as follows.

The memory (main memory 12a,
The sub-memory 20a) stores the RA with the backup power supply.
It was configured to be either M or E ² PROM.

In the above-described embodiment, the sub failure codes are # 1 to # 99, but are not limited to this number, and may be a more detailed division or a larger division.

[0053]

According to the first aspect of the present invention, E
When a failure occurs in any of the CU and the external device, in addition to creating a first failure code (main failure code) for specifying the failure location, when a failure occurs in the ECU, the content of the failure is described. A second failure code to be specified, that is, a sub-failure code corresponding to the detailed location of the ECU failure is created and configured to be readable, so that the vehicle manufacturer or the ECU manufacturer sends the E transmitted from the dealer.
It is easy to specify the cause of the CU failure (abnormality).

According to the second aspect of the present invention, since the second fault code is output as a pulse train, it is not necessary to add a special circuit for reading the fault code. With a simple configuration using an oscilloscope or the like, the cause of a failure (abnormality) of the ECU can be specified.

According to the third aspect of the present invention, the fault code, particularly the second fault code, is stored in a memory such as a RAM having a backup power supply or an E ² PROM. Therefore, the vehicle manufacturer or the ECU manufacturer can more reliably read the second failure code.

[Brief description of the drawings]

FIG. 1 is an explanatory block diagram for describing a configuration of a vehicle electronic control unit according to one embodiment of the present invention.

FIG. 2 is a flow chart showing a process for creating and storing a fault code according to the fault (location and content) when a fault occurs in an internal device or a connected external device of the vehicle electronic control unit shown in FIG. 1; is there

FIG. 3 is a flowchart showing an output process when reading a sub failure code from a main memory or a sub memory in the electronic control unit for a vehicle shown in FIG. 1;

FIG. 4 is an explanatory diagram schematically showing output modes A to C constituting a pulse train for outputting a sub failure code.

FIG. 5 is an explanatory diagram schematically illustrating a pulse train when a sub failure code is # 12.

FIG. 6 is an explanatory block diagram for explaining a configuration of a vehicle electronic control unit according to the related art.

[Explanation of symbols]

 Reference Signs List 10 vehicle electronic control unit (ECU) 12 main CPU 12a main memory 14 input / output circuit 16 sensor 18 actuator 20 sub CPU 20a sub memory 22 memory 24 warning lamp 26 diagnostic device 28 harness

Claims (3)

[Claims] At least one CP mounted on a vehicle is provided.
U, a memory, and an input / output circuit, wherein the electronic control unit for a vehicle is connected to an external device via the input / output circuit. When a failure occurs in any of the vehicle electronic control unit and the external device, a first part for specifying the failure location
First failure code creation means for creating the failure code and storing it in the memory; b. Means for generating a second fault code specifying the content of the fault when the fault occurs in the vehicle electronic control unit, and storing the second fault code in the memory; c. When connected to an external diagnostic device, the stored first
Electronic control unit for a vehicle, comprising: a failure code output unit that outputs a failure code and a second failure code. 2. The electronic control unit for a vehicle according to claim 1, wherein the failure code output means outputs at least the stored second failure code as a pulse train. 3. The electronic control unit for a vehicle according to claim 1, wherein the memory is one of a RAM provided with a backup power supply and an E ² PROM.