JPS5825545A - Electronic device for vehicle - Google Patents

Abstract

PURPOSE:To reduce the capacity of a program memory by incorporating a nonvolatile memory, data in which is not erased even at the time of power failure, in an information supply device for car and by using it together with an electronic control device for engine. CONSTITUTION:A digital control device for vehicle, 1000, performs controls and self-judgement for fuel injection, ignition, EGR, idling, etc. on the bais of signals for revolving speed, 02 and car speed given by a crank angle sensor etc. and also of signals given by switches. These inputs are forwarded through a car information supply device 2500 while operated values and results by the control device 1000 are transferred to the information supply device to be accommodated in its nonvolatile memory 2530. When the judgement results in a command for display, the data is read and given on the display 2520. Accordingly, only one nonvolatile memory is required and the read and display is carried out from the nonvolatile memory every time the command is given, so that the program can be made simple and the time of execution shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle electronic control device that shares a non-volatile memory for a plurality of electronic control devices each using a microcomputer (hereinafter abbreviated as a microcomputer). Regarding equipment.

An example of a conventional vehicle electronic device equipped with a plurality of vehicle digital control devices is shown in FIG. In the figure, reference numeral 1 denotes an engine electronic control unit, which not only controls the engine but also diagnoses whether each input and output is normal or abnormal.

The diagnostic results are stored in the non-volatile memory 2 built into the engine electronic control device 1, so that the diagnostic results will not be erased even if the ignition switch is turned off and the power to the engine electronic control device 1 is turned off. has been done.

Reference numeral 3 denotes a vehicle information providing device, which not only conveys the operating state of the vehicle to the occupants through a display 4, etc., but also transmits data during the calculation of the operating state and the calculation results to a non-volatile memory 5 built in the vehicle information providing device 3. Therefore, for example, the data during the calculation of the distance traveled to the destination and the calculation results are not erased even if the ignition switch is turned off, and the calculation can be restarted.

Further, the engine electronic control device 1 and the vehicle information providing device 3 are connected to the data transfer line 6, and the vehicle information providing device 3 is connected to the data transfer line 6.
When a command to display diagnostic results is input to the vehicle information providing device 3, the vehicle information providing device 3 transmits the diagnostic results stored in the non-volatile memory 2 of the engine electronic control device 1 to the vehicle information providing device 3 via the data transfer line 6. instruct them to send it to. Then, the engine electronic control device 1 transmits the diagnostic results stored in the non-volatile memory 2 to the vehicle information providing device 3 via the data transfer line 6, and the vehicle information providing device 3 transmits the diagnosis results on the display 4, etc. Display the system diagnosis results. In this way, the diagnostic results obtained by the engine electronic control device 1 are retained even after the power is turned off.
The diagnostic results can be displayed at any time.

However, in such a conventional vehicle electronic device, each of the engine electronic control device 1 and the vehicle information providing device 3 has a non-volatile memory 2, 5, and the diagnostic results of the engine electronic control device 1 and the vehicle information are stored. The calculation results of the providing device 3 are stored in the respective non-volatile memories 2 and 5 and retained even after the power is turned off, and when displaying the diagnostic results, they are transferred from the engine electronic control device 1 to the vehicle information providing device 3. Structure to display.

Therefore, non-volatile memory is required for both devices, resulting in high costs.Also, after the diagnostic result display command is input to the vehicle information providing device 3, the diagnostic results are not transmitted from the engine electronic control device to the vehicle information. Since the information is transferred to the providing device, there are problems in that it takes time and the program becomes complicated.

The present invention has been made by focusing on such conventional problems, and is designed to share the nonvolatile memory of the engine electronic control device and other vehicle digital control devices with the nonvolatile memory of the vehicle information providing device. Immediately after the diagnosis, the results diagnosed by the engine electronic control device are transferred to the vehicle information providing device, stored in the non-volatile memory of the vehicle information providing device, and the vehicle information providing device is instructed to display the diagnostic results. It is an object of the present invention to solve the above-mentioned problems by configuring the system to immediately read out and display the diagnostic results from the nonvolatile memory of the vehicle information providing device when the information is input.

Hereinafter, the present invention will be explained based on the drawings.

FIG. 2 is a configuration diagram showing an embodiment of the present invention.

In the figure, reference numeral 1000 denotes an engine electronic control device (engine computer, hereinafter abbreviated as "base"), which controls the engine and diagnoses each sensor input and actuator drive output. Reference numeral 2500 denotes a vehicle information providing device (drive computer, hereinafter abbreviated as "base"), which performs predetermined calculations according to each command input by the user.
Connected to 500 (5) The button stores the diagnostic results that have been processed and transferred by the E/C1000, retains this even after the power is turned off, and uses the retained diagnostic results the next time the power is turned on. This allows calculation and display to be restarted.

E/C1000 and D/C2500 are data transfer line 2
The E/C 1000 diagnoses the input of each sensor and the drive output of the actuator, and transfers the diagnosis results to the D/C 2500 at any time.

The D/C 2500 stores the received diagnostic results in a nonvolatile memory 2520 so that they are retained even when the power is turned off. Then, depending on the user, D/C250
When a command to display the diagnosis result is input to 0, the diagnosis result is read from the non-volatile memo 2530 and displayed on the display 252.
Send to 0 and display.

Note that the nonvolatile memory 2530 includes MNOS and EEP.
It is possible to use ROM or bubble memory, etc.
It is also possible to use a backup method in which a memory with low current consumption such as 0MO8 is always supplied with power only to the memory portion.

(6) In the above explanation, an example of the engine electronic control device V1000 and the vehicle information providing device D/C2500 was explained.
Instead of LOOO, the present invention may be applied to other vehicle digital control devices such as a torque converter electronic control device and an anti-skid electronic control device.

Alternatively, as shown in Fig. 3, a plurality of vehicle digital control devices 2700, 2800... and one controller 2500 are connected via data transfer lines 2610, 2620..., L
, non-volatile memory 2530 built into the D/C2500
may be shared.

Next, the configuration of the engine electronic control device E/C 1000, the diagnostic control performed by VclOoo, the configuration of the vehicle information providing device D/C 2500, and the data transfer line 2600 will be described in detail below.

An overview of the system of the first engine electronic control unit E/C1000 will be explained based on FIG. FIG. 4 shows a case where the present invention is applied to a 4-cycle, 6-cylinder engine, and the object of control is the following energization.

(1) Fuel injection (EGI) control performed by controlling the valve opening start timing and valve opening time of the injector 15 provided in each cylinder of the engine.

(2) Ignition (IGN) control that controls energization/cutoff of the primary coil of the ignition coil 20 to control ignition timing and energization time.

(3) Exhaust gas recirculation (EGR) in which the lift amount of the EGR valve 30 is controlled by negative pressure using the 76M valve 40.
)control.

(4) Idle rotation (ISC) control in which the lift amount of the AAC valve 50 is controlled by negative pressure control using the 76M valve 40, and the amount of air bypassing the throttle valve 510 is controlled.

The above are the main objects of control, but there are also the following as incidental control or information output. (5) On/off control of fuel cylinder 7'530 by control of fuel pump relay 60 (F/l'), (6) Output of fuel consumption data to fuel consumption needle 70 (FCM), (7) System self-diagnosis (this will be explained in detail later) and data exchange with the checker 2000 or vehicle information providing device 2500 (CHECK), (8) output of a warning to the alarm lamp 80 based on the self-diagnosis result (ALARM).
), (9) Display of self-diagnosis results, etc. on the display 1900 (MONIT).

In order to perform the above control and output, the following control information is obtained from the engine and each part of the vehicle.

(1) From the crank angle sensor 200 built into the distributor 520, R rises every 1200 degrees with the rotation angle of the crankshaft (twice the rotation angle of the distributor).
By counting the rise and fall of the EF signal 201 and every 1 degree, the rotation angle position (θ) of the crankshaft can be detected, and the frequency or period of the REF signal 201 and the POS signal 202 can be detected. By measuring this, the engine rotational speed (Nrprn) can be measured.

(2) Engine intake air amount Qa is determined by air flow meter 2
10, and the intake air amount Qa is inversely proportional to the air flow meter output voltage signal (AFM) 211.

(3) The 02 sensor 220 detects the oxygen concentration in the exhaust gas (9
) The output voltage changes according to the signal (02) according to the air-fuel ratio.
221' is obtained.

(4) A voltage signal (Tw) 231 representative of the engine temperature is obtained by the water temperature sensor 230.

(5)°In-vehicle patch! J240 fully supplies electricity to each part of the control system. Mains power supply 241 to control unit 1000 via control unit relay 540
and an auxiliary power source 242 directly input from the cutter 240. The voltage signal (Va) 241 of the main power supply is also used as information for control.

In addition, the ON terminal 26 of the ignition switch 260
Since the battery voltage is applied not only in the ON position but also in the 5TART position, the control function is maintained even during cranking.
A main power source 241 is supplied to the unit 1000.

(6) A signal (VSP) 251 having a pulse density proportional to the vehicle speed is obtained by the vehicle speed sensor 250.

(1) Ignition switch 260 is turned on (En-)
This is the switch that the driver operates to start and operate the engine, and the voltage signal of the 5TART terminal (5TART) 261
(10) It is possible to know whether cranking is in progress.

(8) Throttle Pulp Gui 1. Tsu f2. F0
1r! This is a switch that closes the throttle pulp when the opening is below a predetermined opening degree, and the opening/closing of the throttle pulp is detected by the opening/closing signal (IDLE) 271.

(9) Air conditioner switch 280id A switch that closes when the near conditioner is activated, and detects whether the air conditioner is operating based on its terminal voltage signal (A/C) 281.

The αQ neutral switch 290 is a switch that closes when the gear position of the transmission is in the neutral or parking position, and its open/close signal (NEU
T) 291 detects the gear position of the transmission.

Each signal explained above is transmitted to the control unit 1000.
input and output to. In addition to the input/output to the control unit 1000, a checker 2000 for displaying the results of diagnosis of the control system is connected via the check connector 201o and the connection transfer connector 2510. . The control unit) 100O has a microcomputer, determines the control state of each controlled object based on the above control information (input signals), outputs a control signal (output signal), and optimally controls the engine. Output relevant information.

Next, we will introduce a control system that comprehensively performs the above-mentioned control.
The circuit configuration of Units) 1000 will be explained based on FIG.

1100 is a signal shaping circuit that inputs various input signals from the engine and various parts of the vehicle, removes noise from these various input signals, absorbs surges, and converts the signals to the control unit.
In addition to preventing malfunctions caused by noise and damage caused by surges, various input signals are amplified and converted to create the next input interface circuit! Arrange it so that the 200 can operate properly. 1200 is an input interface circuit that performs analog-to-digital (AD) conversion of various input signals shaped by the signal shaping circuit 11-00, counts the number of pulses during a predetermined time, and converts the input signals into the next center signal. The arithmetic processing unit (CPU) 1300 converts it into a digital code signal so that it can read it as input data, and stores it in an internal register as input data. A central processing unit (CPU) 1300 operates in synchronization with a clock signal based on an oscillation signal 1311 of a crystal oscillator 1310, is connected to each part via a bus 1320, and is connected to a mask ROM 1410 and a PROM 1420 of a memory 1400. Executes the stored program, reads various input data from each register in the input interface circuit 1200, performs arithmetic processing to calculate various output data, and outputs the output interface circuit FI & xso.
Output data is sent to the register in o at a predetermined timing. The memory 1400 is a data storage device, and the mask R
OM1410, PROM 1420, RAM l 43
Q and a storage memory 1440. The mask ROM 1410 stores the program executed by the CPU 1300 and the data used when executing the program.
The PROM 1420 is a mask ROM 1410 that is permanently stored during manufacturing and can be changed depending on the car model and engine type (13).
control unit)
Write and store it permanently before incorporating it into ilooo. In addition, RAM1430 is a readable and writable memory.
Data stored during arithmetic processing and result data that are temporarily stored before being sent to the output interface circuit 1500 are stored, and this stored content is stored when the ignition switch 260 is turned off and the main power supply 241 is turned off. and not retained. More memory retention notes! J144
0 stores the result data and intermediate data of the arithmetic processing even when the ignition switch 260 is turned off, that is, when the car is not being driven. Note that the memory 1400 does not include a nonvolatile memory.

1350 is an arithmetic timer circuit that enhances the functions of the CPU 1300, including a multiplication circuit for speeding up arithmetic processing, an interval timer that sends an interrupt signal to the CPU 1300 at every predetermined time period, and a timer circuit that the CPU 1300 uses to detect predetermined events. It has a free-run calendar (14) that allows you to know the elapsed time from one event to the next event and the time of event occurrence. An output interface circuit 1500 receives output data from the CPU 1300 into an internal register and converts it into a signal having a predetermined timing and time width or a predetermined period and data ratio. 9, convert it into a switching signal of '1.0 and send it to the drive circuit 1600. The drive circuit 1600 is a power amplification circuit that receives a signal from the output interface circuit 1500 and amplifies voltage and current using a transistor or the like to drive various actuators or perform display.
Or control unit) 100OK connector 2
A system connected via 010 to diagnose the control system,
An output signal is sent to checker 2000 for displaying the result.

Reference numeral 1700 is a backup circuit that monitors the signal of the drive circuit 1600 and uses the signal shaping circuit 1 when the CPU 1300, memory 1400, etc. fails and does not operate normally.
In response to part of the signal from 100, the engine rotates and generates the minimum necessary control output to drive the vehicle, and also generates a switching signal 1701 to notify of the occurrence of a failure. 1750 is a switching circuit which cuts off the signal from the output interface circuit 1500 in response to the switching signal 1701 from the backup circuit 1700;
Passes the signal from 00.

1800 is a power supply circuit, which connects the line of the main power supply 241 to an input interface circuit 1200, a CPU, 1300,
Memory 1400 and output interface circuit 15
5V constant voltage (Vcc) 18 for microcontrollers such as 00
10. 5y constant voltage (V
Bu ) 1820, ignition. switch 26
Signal indicating on/off of 0 (IGN SW) 183
0, Reset signal (RESET) 1840, CPU
Signal to stop the operation of 1300 (HALT) 1850
, a constant voltage of 8V (AVcc) 1860 for the AD conversion circuit in the input interface circuit 1200, a constant voltage (VAD) to each of the common input/output signal processing circuits of the signal shaping circuit 1100, drive circuit 1600, and switching circuit
D) Output 1870 and supply each circuit. Further, from the auxiliary power supply 242, 5
A constant voltage (VDM) 1880 of v is generated and output to the storage memory 1440.

Next, the diagnostic control performed in the E/C 100O will be explained.

Among the various controls performed by E/C100O, rC
There is a self-diagnosis program called HECK J. This program is one of the pack ground programs among the E/C100O's various program groups, and is always running (CPU, 130
0) is executed whenever there is free time, and checks the validity of various input signals and drive outputs of various actuators.

The data of this diagnosis result is E/C1 as shown in Figure 2.
D/C2 from 00O via data transfer line 2600
500, a non-volatile memo in the formant shown in Figure 6! The specified location of J 2530 (Hexadecimal display $
802$ is a symbol indicating that it is expressed in hexadecimal, the same applies hereinafter. ) is saved in the area starting from . As is clear from Figure 6, the diagnostic result data consists of 8 pins for each input/output area)
(17) of (1”) information is aggregated and saved, and is stored on the D/C2500 (or
When there is a request from the checker 2000) or when a warning is required, the display 2 of the D/C 2500
Convey information to 520 etc.

In order to check the validity of various input/output signals for engine control, it is necessary to use a checking method that corresponds to the unique characteristics of the signals. The checking method must have some degree of redundancy. In order to satisfy these conditions, the following checking method is used.

As mentioned above, the input signals for engine control include the crank angle top dead center (REF) signal 201 and the crank angle (p
os) signal 202, engine coolant temperature ('rw) signal 231, and various other output signals for driving the actuator. As an example, the engine coolant temperature ('rw
) A method for checking the validity of the signal 231 will be explained.

The water temperature sensor 230 is composed of a thermistor, and has a characteristic that its resistance value changes according to a change in temperature (18 degrees). Utilizing this characteristic, a voltage v8 is supplied to the control circuit shown in FIG.
Read as the change in voltage.

For example, if the water temperature sensor 230 or its wiring is short-circuited, Ov is input to the 'rw input terminal of the control circuit, and if the water temperature sensor 230 or its wiring is broken, the supply voltage vs is input to the resistor R2 and R
The voltage vmax divided by 3 is input. These temperatures are either unavoidable under normal conditions, or correspond to extremely high or low temperatures, so for a specified period of time after engine startup (
Several minutes = 1. ) Even if the above value is 0・V or vnlax(v)
is input to the TV terminal 232, it can be determined that there is a failure in the water temperature sensor system (sensor 230 itself, signal line to input terminal 232, converter, etc.). Furthermore, due to the nature of the engine cooling water, it is highly unlikely that the temperature will rise from +80°C to ~30°C or +180°C within a few seconds. Therefore, even if the signal value of the cooling water temperature suddenly changes within a few seconds, it can be determined that there is some kind of failure in the water temperature sensor system. Also, after a sufficient period of time (about 15 minutes or more) has passed after the engine has started, the cooling water temperature is generally considered to be around 80°C ± 20°C, so even if the temperature is outside of this range, , there is some kind of abnormality (however, it is not necessarily the sensor system).
It is necessary to judge.

When the CHECK 7' program detects such an abnormality, it stores data in the non-volatile memory 253 as shown in FIG.
For each 0 signal, the number of times corresponding to the mode of a predetermined location (address $80 in the case of cooling water temperature) is incremented. The mode referred to here means, for example, the water temperature sensor 230
If °, MODE-15 disconnection, MODE-2
=Shiyoto.

Here, MODE -1 and MODE -2 each have 3
bits), so 0 to 7 (000 to 111)
) can hold up to 8 levels of information.

The CHECK program increments a predetermined number of MODEs and then compares whether or not this number exceeds a predetermined reference value according to the characteristics of the input signal of each sensor.

The reference value generally needs to be determined according to the characteristics of the various sensor signals and their importance in engine control, but in the case of the water temperature sensor 230, as mentioned above, the signal line is configured to always have a current flowing through it, and other Since there are no active elements, there is no possibility of electrical noise being mixed in, or sudden temperature changes in the cooling water itself. Therefore, the water temperature ('
rw) If a sudden change occurs in the signal value fc, it is considered that there is a very high possibility that some kind of failure has occurred, and in the case of the water temperature ('rw) signal, the reference value to be compared is "2".
and set.

If either MODE-1 or MODE-2 exceeds this reference value, the failure degree count (2 bits are allocated) is incremented as shown in the timing chart of Figure 7. , applicable MODE
Clear the count of times.

In this way, each input/output signal (21 ), it is possible to obtain the degree of failure of each part normalized to a certain level.

Note that FIG. 9 shows a schematic flowchart when the above processing is performed regarding the cooling water temperature (TW).

Next, the water temperature sensor check program will be explained with reference to FIG.

First, it is determined whether the engine has started (1).

If the engine is started here, ts after starting in (2)
Determine whether time has elapsed. If the water temperature is below -30°C even though t3 hours have passed, it is determined that the water temperature sensor is malfunctioning (3). If it is determined that there is a failure, MODE2 is incremented (4). Here, in MODE 2, failure degree SUB is compared with a reference value, and if it is smaller than the reference value, the failure degree is not incremented.

This acts as a filter so that even if the signal of the water temperature sensor is temporarily disturbed due to noise etc., it will not be judged as a malfunction (2), a*, if MODE 2 exceeds the reference value. , Increment the failure degree α → , 0 groan. Next, in (6), calculate the value of 'rw (previous) -Tw, (current), (22) In other words, the difference between the water temperature measured last time and the water temperature measured this time. , if the value of w is greater than the standard value, that is, if the current water temperature value has increased by more than + from the previous water temperature value, MODE
Increment 1 and jump to failure mode SUB (7
) , (8) , (Wow.Next, if the 11 lotus value is much smaller than the standard t value, that is, if the water temperature value decreases by more than one point from the previous water temperature value to the current water temperature value, then , M.O.
Increment DE 2 and jump to failure mode SUB (9), (10, (5).

As described above, cases are detected in which the water temperature does not rise above -30° C. even after tB time has elapsed since the engine was started, and cases in which the water temperature value changes rapidly.

Next, an overview of the vehicle information providing device D/C 2500 will be explained with reference to FIG. 10.

The D/C 2500 inputs a plurality of vehicle information from various sensors attached to various parts of the vehicle, measures and arithmetic processes the information using the drive computer 2500, and displays the display 2520 such as a switching display and a dedicated display. In addition to independently displaying and switchingly displaying the measurement and calculation results, it also controls the radio using a program reservation function, and controls the buzzer using an alarm function. And D/C25
00 has a built-in non-volatile memory 2530, which is processed by the data transfer line 2530 as described above.
E/C10 transferred to D/C2500 via 600
Stores the diagnostic results of various input/output signals of 00 and turns off the power.
−Keep it afterward.

In addition, in the figure, 2540 is the key date, and also the D/C
2500 can also be organically connected to other systems 2550 such as v.

The functional items of the D/C2500 are listed below.

(1) U-Gio program reservation...Key dart (SW,
) 2540, if you memorize the desired time and desired broadcasting station, the current time (input from the clock) will be compared with the stored time, and when they match, the memorized broadcasting station will be selected. A control signal (including turning on the radio) is output to the radio so that the radio is turned on. The display switches between the memorized time and station.

(2) Alarm: If the desired time is stored in the same way as in (1), a buzzer will sound if the time matches as a result of time comparison. The display changes to display the stored time.

(3) Trip meter...When the trip meter is displayed,
Display measurement. The display will be switched.

(4) Navigation meter... Planned average vehicle speed V when the key is in - mode
When s is set, the traveling distance and traveling time T from that point are measured, and the actual average vehicle speed (D/'r), the time difference from the scheduled time (D/vs T), and the distance difference from the scheduled time (D- V
s/T).

(5) Fuel consumption... When displaying the consumption amount, the key is in - mode 2.
The fuel consumption amount from the time when the clear SW on 540 was operated is counted and displayed (switchable display).

(6) Fuel consumption meter: Measures the mileage and fuel consumption at regular intervals, and calculates and displays the division results (switchable display).

(25) (7) Speedometer: Measures the distance traveled at regular intervals and displays the droplets (independent display).

(8) Odometer: Measures and displays the cumulative mileage since the vehicle was completed (independent display). It differs from a trip meter in that it cannot be reset.

(9) Remaining drivable distance: Measures the remaining amount in the fuel tank, multiplies it by the calculation result of (6) (fuel consumption), and displays the calculation result (switch display).

α1 tachometer: Counts and displays (switchable display) the number of engine revolutions at regular intervals.

It also has a memo function that stores and displays arbitrary numbers, and a calculator function that allows you to perform four arithmetic operations.

Alpha Diagnosis...When a command to display diagnostic results is input from the keyboard 2540, a non-volatile memo! The diagnostic results are read from the J2530 and sent to the display 2520 for display.

Various sensors and actuators for obtaining input information to perform the above-mentioned functions include the following.

(1) Clock: The time signal source outputs the clock's display time (26) - evening as a serial signal.

(2) Distance sensor: 1 every time the vehicle travels a certain distance
A sensor that outputs pulses, usually by rotating a magnet at an angle proportional to the rotation of the shaft it covers.

(3) Fuel consumption sensor: Outputs one pulse every certain amount of fuel consumption. This integrates the fuel injection time in the fuel injection (EGI) control by the E/C 100O mentioned above, and outputs a pulse every time the fuel injection amount reaches a constant value.

(4) Electronic radio (electronic team): A radio that can be controlled with a 0N10FF power supply, AM/FM switching, and channel selection using external electrical signals.

(5) Alarm budday...This is a normal buddy.

(6) Remaining fuel level sensor: This is a general fuel gauge.

(7) x 7) Rotation sensor: Detected by the ignition knob or the crank angle sensor in the E/C100O mentioned above.

(8) Display...The speedometer display is a dedicated display that independently displays the speedometer, and is a dynamic drive type using a 3-digit 7-segment display.The odometer display is a dedicated display that independently displays the odometer. So, 6 digits 7
It is a dynamic drive type using a segment display, and the switching display is the above-mentioned (1) to (6), (9), α.
It has a 6-digit dynamic drive 7-segment display and an independently controlled unit display.

(9) Input device (keyboard) 2540...Instructs to switch display items, or sets average vehicle speed of navigation meter,
Input data such as desired time and station settings for radio program reservations,
This is used to issue commands to display diagnostic results for various inputs and outputs in the E/C100OK.

The engine electronic control device (E/C) 1000 and the vehicle information providing device (D/C) 2500 described above are connected via a data transfer connector 2510, as shown in FIGS. 2 and 4. They are connected via a transfer line 2600. The signal transfer system between both devices is HD6
8 (Uses 11SO's Full Dusolex asynchronous serial communications interface.

Then, when the ignition switch 260 is turned on, both devices are initialized, necessary data is stored, and a transmission/reception program is executed as necessary to transfer information.

As explained above, according to the present invention, the results diagnosed by the engine electronic control device or other vehicle digital control device are transferred to the vehicle or the image information providing device and stored in the nonvolatile memory of the vehicle information providing device. When a command to display the diagnostic results is input to the vehicle information providing device, the diagnostic results are read from the nonvolatile memory and displayed on the display, so the nonvolatile memory is stored in the vehicle information providing device. One medium-sized nonvolatile memory is sufficient, and the cost is lower by using one medium-sized nonvolatile memory than two small-sized nonvolatile memories. In addition, only one sequence circuit is required for writing, which also reduces costs.

Furthermore, regarding the display of diagnostic results, when a diagnostic result display command is input to the vehicle information providing device, the program reads out the stored diagnostic results from the non-volatile (29) memory of the vehicle information providing device and displays them. This has the effect of greatly simplifying the process, significantly shortening the execution time, reducing the capacity of program memory, and lowering costs.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a conventional vehicle electronic device, FIG. 2 is a configuration diagram of a first embodiment of the vehicle electronic device of the present invention, FIG. 3 is a configuration diagram of a second embodiment, and FIG. Figure 2 is a system configuration diagram of the engine electronic control device, Figure 5 is a circuit diagram of the control unit used in the system in Figure 4, and Figure 6 is a system configuration diagram of the control unit used in the system shown in Figure 4.
The figure shows the format of the diagnostic results stored in nonvolatile memory, Figure 7 is the timing chart for calculating the diagnostic results in Figure 6, Figure 8 is the control circuit diagram for engine water temperature signal detection, and Figure 9 is the engine water temperature signal detection diagram. The flowchart of the diagnostic program, FIG. 10, is a system configuration diagram of the vehicle information providing apparatus shown in FIGS. 2 and 3. 230... Water temperature sensor, 231... Engine cooling water temperature (Tw) signal, 1000... Engine electronic control unit,
(30) 2500...Vehicle information providing device, 2520...Display device, 2530...Nonvolatile memory, 2540...Keyboard, 2600.2610.2620...Data transfer line, 2700.2800...・Digital control device for vehicles. Patent Applicant Nissan Motor Co., Ltd. Patent Application Agent Megumi Yamamoto - #qConcave#aFigure 30

Claims (3)

[Claims] (1) In a vehicle electronic device that connects a vehicle information providing device that conveys the operating status of the vehicle to the occupants and an engine electronic control device that controls the engine and diagnoses various input/output signals via a data transfer line, A vehicle characterized in that the vehicle information providing device has a built-in nonvolatile memory whose stored information does not disappear even when the power is turned off, and the nonvolatile memory is shared by both the engine electronic control device and the vehicle information providing device. electronic equipment. (2) The diagnostic results of various input/output signals of the engine electronic control device, which have been processed by the engine electronic control device, are stored and saved in the nonvolatile memory built into the vehicle information providing device, and the vehicle information 2. The device according to claim 1, wherein the device reads and displays the diagnostic results from the nonvolatile memory in response to a diagnostic result display command input to the providing device. (3) A plurality of vehicle digital control devices including an engine electronic control device are connected to the vehicle information providing device through data transfer lines, and the nonvolatile memory built in the vehicle information providing device is used to provide the vehicle information. 2. The device according to claim 1, wherein the device is shared by all of the plurality of vehicle dinotal control devices.