JPH01155231A - Vehicle diagnostic apparatus - Google Patents

Abstract

PURPOSE:To simply and acturately allow the communication apparatus of a diagnostic apparatus main apparatus to synchronize to the control apparatus of a vehicle, in the vehicle diagnostic apparatus connected to a vehicle control apparatus, by selecting the communication system corresponding to the machine kind signal outputted by a decoder to fix the same. CONSTITUTION:When a vehicle diagnostic apparatus main body 25 is connected to a vehicle control apparatus 2 to turn a switch 43 ON to perform initialization, the decoder of the I/O 39 of the control part 28 of the apparatus 25 decodes an inputted signal to output the corresponding machinery kind discrimination signal. The communication system selection means of the I/O 39 judges whether the communication system selected through a CPU 36 and an ROM 41 is synchronous to the apparatus 2 and, in a synchronous case, said communication system is fixed and, by the communication between the apparatus 2 and the main body 25 based on this system, the diagnosis corresponding to the indicated mode is performed. By this method, the communication apparatus of the diagnostic apparatus main body can be made automatically and accurately synchronous to the control apparatus of a vehicle.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a vehicle diagnostic system that automatically selects a communication system of a diagnostic device body that is synchronized with a communication system of a control device mounted on a vehicle. Regarding equipment.

[Problems to be solved by conventional techniques and inventions] In recent years,
The air-fuel ratio of the engine installed in a vehicle is electronically controlled to provide comfortable drivability, purify exhaust gas, save fuel, and improve engine output.

Output signals from various sensors that detect engine conditions,
Alternatively, if output signals to various actuators such as injectors are not accurate, it becomes difficult to accurately control the engine, leading to decreased drivability, worsened exhaust emissions or fuel efficiency, and decreased engine output.

With today's increasingly complex electronic control systems, even if a failure occurs in a control device, sensor, or actuator, it is difficult to immediately determine the cause of the failure. It is essential to be equipped with a vehicle diagnostic device, a so-called hand computer, which can easily check output signals from various sensors for the vehicle or signals output from the electronic control device to various actuators.

For example, in the vehicle diagnostic device disclosed in Japanese Patent Application Laid-Open No. 58-12848, a dedicated checker measures the fuel injection pulse time and
A technology has been disclosed that can automatically diagnose whether the idle speed is normal or not by measuring the number of engine rotations.

By the way, the communication system of the control device mounted on the vehicle has different communication methods (start-stop synchronization, clock synchronization, etc.), communication speed (baud rate), etc. depending on the model and model year. As with the prior art described above, where the vehicle is diagnosed using a dedicated checker, the target models are limited, and it is necessary to prepare a number of vehicle diagnostic devices corresponding to each model, which is not only inconvenient to use but also inefficient. It is.

In addition, in order to be compatible with a wide variety of control devices,
In vehicle diagnostic equipment that has multiple communication systems built into its parts,
First, it is necessary to input the model code manually to select and fix the communication system.

However, as the number of compatible models increases, the number of digits in this model code increases, making it easy to operate incorrectly and causing problems in operability. Furthermore, if an incorrect model code is input, a communication system corresponding to the communication system of the control device mounted on the vehicle will not be selected, which will hinder diagnostic work.

[Object of the Invention] The present invention has been made in view of the above circumstances, and eliminates human error in the model code and allows easy operation to set the 1I1111 of the vehicle.
It is an object of the present invention to provide a vehicle diagnostic device that can easily synchronize the communication systems of the main body of the diagnostic device into one device, has good operability, and is economical.

[Means and effects for solving the problems] The present invention provides a vehicle diagnostic device that is connected to a control device mounted on a vehicle and diagnoses input/output signals of the control device. The control unit has a plurality of communication systems corresponding to the communication systems of the control device that differ depending on the model, and selectively conducts when one of the plurality of input terminals is connected between the control device and the main body of the diagnostic device. a decoder that decodes a signal obtained by decoding and outputs a model identification signal, and a communication system selection means that selects and fixes a communication system corresponding to the model identification signal of the decoder from among the plurality of communication systems. It is something.

That is, when the control section of the diagnostic device main body is connected to a control device mounted on a vehicle, any one of the plurality of input terminals connected to the decoder is selectively turned on. The decoder decodes the signal obtained from the electrically connected input terminal and outputs a model identification signal to the communication system selection means. Then, the communication system selection means selects and fixes the communication system corresponding to this model identification signal from among the plurality of communication systems.

[Embodiment 1 of the invention Hereinafter, the present invention will be described in detail with reference to the drawings.

1 to 4 show a first embodiment of the present invention, and FIG.
a) is an external view of the vehicle, Fig. 1 (1)) is an external view of the vehicle diagnostic device, Fig. 2 is a block diagram of the vehicle control device and the vehicle diagnostic device, and Fig. 3 is the control unit of the diagnostic device main body. FIG. 4(a) is a flowchart showing the communication system selection procedure, and FIG. 4(b) is a flowchart showing the vehicle diagnosis procedure.

In the figure, numeral 1 is a vehicle such as the own vehicle A, and 2 is a control unit (ECU) installed in this vehicle 1 that performs air-fuel ratio control, etc., and is read as the central processing unit (CPU) 3 of this ECU 2. dual-purpose memory (RAM) 4 and read-only memory (
ROM) 5, an input interface 6, and an output interface 7 are connected via a path line 8.

In addition, a cold section water temperature sensor 9 is connected to the input interface 6.
water temperature signal TV, air-fuel ratio feedback signal λ of 02 sensor 10, intake air amount signal Q of intake pipe negative pressure sensor 11
1 Air conditioner operation signal SWa of air conditioner switch 12 1
Vehicle speed signal S1 from vehicle speed sensor 13 Idle operation signal 5Wi1 from idle switch 14 Throttle opening signal Trθ from throttle opening sensor 15, neutral switch 16
The neutral operation signal S-〇, the rotation speed signal N of the engine rotation speed sensor 17, etc. are input.

The ECU 2 processes the various signals described above according to the program stored in the ROM 5 and stores them in the RAM 4.
Once stored, the CPU 3 performs various arithmetic processing based on the stored data, and a control signal based on the processed data is sent to the output interface 7 and the drive circuit 18 to control the canister. It outputs to the device 19, EGR actuator 20, idle control actuator 21, ignition coil 22, and injector 23 to control the operation of these actuators.

Further, the ECLJ 2 is provided with an external connection connector 24, and a connector 26 provided on a diagnostic device main body (so-called hand computer) 25 is connected to this external connection connector 24 via an adapter harness 27. Ru.

This adapter harness 27 is prepared in correspondence with the communication system of the ECU 2, which differs depending on the model.

This diagnostic device main body 25 is provided for a dealer's service station, etc., and is provided with a control section 28, a power supply circuit 29, etc. inside, and an indicator section 30. A display 31, a keyboard 32, a power switch 43, and the like are provided. Furthermore, the control section 2
A removable memory cartridge 34 is connected to the memory cartridge 8 via a connector 33.

Further, the control section 28 is provided with a CPU 36, a RAM 37, and an I10 interface 39, which are connected to each other via a pass line 35.

Note that the CPLJ 36 is provided with a clock pulse oscillation element 42 that outputs a synchronization signal.

Further, the memory cartridge 34 is designed so that the diagnostic device main body 25 itself is compatible with the program of the ECU 2 that differs depending on the car model, and therein is a ROM 4 containing a diagnostic program corresponding to the program of the car model.
1 is provided, and when the memory cartridge 34 is connected to the diagnostic apparatus main body 25, the ROM 41 is connected to the pass line 35 of the control section 28.

Further, the input terminal of the I10 interface 39 receives a diagnosis mode signal from the keyboard 32 and the ECL.
Various control signals output to the drive circuit 18 are inputted from the output interface 7 of I2. Furthermore, this I1
The output side of the 0 interface 39 is connected to the input interface 6 of the ECU 2, the display 31, and the indicator section 30.

Further, the power supply circuit 29 connected to the control section 28 is connected to the power supply Vcc of the vehicle 1 via the power switch 43 and the adapter harness 27.

On the other hand, the I10 interface 39 of the diagnostic device main body 25 includes a communication system selection means 39a, first, second, and third communication systems 39b to 39d, and a decoder 39e, which are connected to each other via the path line 35. It is provided.

When the ECU 2 is synchronized with an external clock, the first communication system 39b outputs a synchronization signal from the internal clock pulse oscillation element 42 of the control section 28 to the ECU 2, and uses this synchronization signal to transmit information signals from the ECU 2. It is synchronized and taken into the control unit 28 of the diagnostic device water 25.

Further, in the second communication system 39c, the ECU 2 takes in information signals to the control unit 28 in a start-stop manner without using synchronization using a clock.

Further, the third communication system 39d includes the ECU 2
If a clock pulse oscillation element is installed inside the internal clock, the information signal is synchronized with the synchronization signal from this internal clock and is input to the control section 28.

Further, the decoder 39e includes a plurality of (three in the figure)
input terminals (1), (2), and (3) are provided, each of which is connected in parallel to the input/output connector 26. Furthermore, this input/output connector 26 is provided with a ground terminal GRD.

On the other hand, the decoder 39 is connected to the connector 27a of the adapter harness 27 connected to the input/output connector 26.
A harness 27b is provided for selectively connecting any one of the input terminals I, I[, and ■ of the input terminal e to the ground terminal GRD.

The adapter harness 27 is prepared in correspondence with the communication system of the ECU 2, which differs depending on the model, and when the ECU 2 is synchronized with the first communication system 39b of the I10 interface 39, as shown in FIG. The harness 27b is set to conduct the input terminal I of the decoder 39e and the ground terminal GRD, and to open the other input terminals (2) and (2).

Further, when the ECLJ 2 is synchronized with the second communication system 39C, the input terminal (2) of the decoder 39e is grounded, and the other input terminal (2) is set to be open.

Further, when the ECU 2 is synchronized with the third communication system 39d, the input terminal (2) of the decoder 39e is grounded, and the other input terminal (2) is set to be open.

This decoder 39e decodes the signals inputted to the input terminals (1) to (4) and outputs a model identification signal to the communication system selection means 39a. When the communication system selection means 39a receives an identification signal from the decoder 39e indicating that the input terminal (2) is grounded, it selects the first communication system 39b and selects the first communication system 39b to indicate that the input terminal (2) is grounded. If the identification signal shown is input, the second communication system 39c is selected, and if the separate signal ti is input indicating that the input terminal 2 is grounded, the third communication system 39d is selected.

On the other hand, the CPU 36 is connected to the communication system selection means 39a via the pass line 35, and the E
An arithmetic unit 36a is provided that performs PfIJ calculation processing on the output signal from Cu2 and outputs a signal for displaying the data value on the display unit 31 or the like.

Next, the diagnostic procedure of the vehicle diagnostic device having the above configuration will be explained according to the flowchart of FIG. 4. Note that this vehicle diagnosis is performed in an actual vehicle condition.

First, select the adapter harness 27 that corresponds to the external connection connector 24 provided on the ECL 12 of the vehicle 1, and connect the external connection connector 24 and the input/output connector 26 of the diagnostic device main body 25 via this adapter harness 27. Connecting.

Then, the harness 27b provided to the connector 27a of the adapter harness 27 connects one of the input terminals 1 to 2 of the decoder 39e of the I10 interface 39 provided to the control unit 28 of the diagnostic device main body 25 to the ground terminal GRD. Make it conductive.

Note that in FIG. 2, the input terminal I is grounded.

Then, the power switch 43 provided on the diagnostic device main body 25 is turned on and initialized (steps 101 and 102).

The decoder 39e decodes the signals input to the input terminals 1 to 2, and outputs a corresponding model identification signal to the communication system selection means 39a.

The communication system selection means 39a first determines whether the ECLJ2 is synchronized with the first communication system 39b from the model identification signal of the decoder 39e (
Step 103). In the case of synchronization, the first communication system 39b is selected and fixed (step 105), and
If not, it is determined in step 104 whether or not to synchronize with the second communication system 39G.

When synchronizing with this second communication system 39c, the second communication system 390 is selected and fixed (step ioe).
, and if not synchronized, the third communication system 39d
is selected and fixed (step 107).

In the illustrated embodiment, since the input terminal (2) of the decoder 39e is grounded, the first communication system 39b is selected and fixed.

Then, the main program in step 108 is executed using the selected communication system capable of bidirectional communication.

Next, the execution procedure of the main program in step 108 will be explained according to the flowchart of FIG. 4(b).

First, the operator first presses the keyboard section 3 of the diagnostic device main body 25.
2 to specify the diagnostic mode you want to monitor (for example, if you want to check the fuel injection pulse time, select F → 1 → 2
→Enter ENT). Then, this diagnostic device main body 25
The diagnostic mode is stored at a predetermined address in the RAM 37 of the control unit 28 (step 110).

Next, the diagnostic mode stored in this RAM 37 is set to CP.
It is called by LJ36 and the contents are interpreted (step 11
1).

Then, a transmission request signal TX of information corresponding to this diagnostic mode is output to the ECU 2 (step 112).

Next, an information signal (for example, fuel injection pulse time) corresponding to the transmission request is transmitted from the ECU 2 to the control unit 28 RX.
is received via the specified communication system (first communication system 39b in the figure) (step 113).
.

This control unit 28 calculates the received information, and
A physical quantity is converted from a base number to a decimal number (step 114).

Then, this physical quantity converted information is displayed numerically on the display section 31 of the diagnostic device main body 25 (for example, 1.3 m
5ec) L/, inform the operator of the fuel injection pulse time (step 115).

Further, FIG. 5 is a block diagram of a vehicle control device and a vehicle diagnostic device according to a second embodiment of the present invention.

As shown in the figure, the input/output connector 2 of the diagnostic device main body 25
The I10 interface 3 is connected to the external connection connector 24 side of the ECU 2, which is connected to the ECU 6 via the adapter harness 27.
A ground terminal GnD may be provided to selectively conduct the input terminals 1 to 2 of the decoder 39e of 9.

Note that the present invention is not limited to the above-mentioned embodiments; for example, it is sufficient to have as many communication systems as are compatible with the model, and two, three or more types of communication systems may be built-in. To identify four or less types of communication systems, the decoder 39e may require two input terminals, and to identify two types of communication systems, it may require - input terminals.

[Effects of the Invention] As explained above, according to the present invention, the control section of the diagnostic device main body, which is connected to a control device mounted on a vehicle and diagnoses the input/output signals of this control device, is responsible for each model. a plurality of communication systems corresponding to the communication system of the control device, and a signal obtained by selectively conducting one of the plurality of input terminals when the control device and the diagnostic device main body are connected; Since the decoder is provided with a decoder that outputs a model identification signal from the decoder, and a communication system selection means that selects and fixes a communication system corresponding to the model identification signal of the decoder from among the plurality of communication systems, bidirectional communication is possible. The communication system is automatically selected.

Therefore, there is no error in inputting the model code, and the communication system of the diagnostic device itself can be easily synchronized with the vehicle control device without the need for inputting the model code, thereby greatly improving operability.

Furthermore, it is economical because one diagnostic device can support multiple communication systems.

[Brief explanation of the drawing]

1 to 4 show a first embodiment of the present invention, and FIG.
a) is an external view of the vehicle, Fig. 1(b) is an external view of the vehicle diagnostic device, Fig. 2 is a block diagram of the vehicle control device and the vehicle diagnostic device, and Fig. 3 is the t11 control section of the diagnostic device main body. 4(a) is a flowchart showing a communication system selection procedure, FIG. 4(b) is a flowchart showing a vehicle diagnosis procedure, and FIG. 5 is a vehicle control device according to a second embodiment of the present invention. FIG. 2 is a block diagram of a vehicle diagnostic device. DESCRIPTION OF SYMBOLS 1... Vehicle, 2... Control device 125... Diagnosis device main body, 28... Control unit, 39a... Communication system selection means, 39b, 39c, 39d... Communication system,
39e...decoder, 1. II, III...Input terminals. Procedural document (method) March 22, 1988 1, Indication of case Patent application No. 31343 of 1988
No. 5 No. 2, Title of the invention: Vehicle diagnostic device 3, Relationship with the case of the person making the amendment Representative of the patent applicant: 1) Toshihiro Shima 5, Date of amendment order: February 23, 1988 (dispatch mortar) 6, Amendment Target [Drawing]

Claims (1)

[Claims] In a vehicle diagnostic device that is connected to a control device mounted on a vehicle and diagnoses the input/output signals of the control device, a control section disposed in the main body of the diagnostic device has the above-mentioned information that differs depending on the model. A plurality of communication systems corresponding to the communication system of the control device and one of the plurality of input terminals are selectively made conductive when the control device and the diagnostic device main body are connected, and a signal obtained is deciphered to determine the model. A vehicle diagnostic device comprising: a decoder that outputs an identification signal; and communication system selection means that selects and fixes a communication system corresponding to the model identification signal of the decoder from among the plurality of communication systems.