JPH0141818B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for automatically starting and stopping an automobile engine, and in particular, it automatically starts the engine when the automobile starts, and after the automobile starts, it automatically starts and stops the automobile. The present invention relates to a method for automatically starting and stopping an automobile engine, which maintains the rotation of the engine and stops the engine when the automobile stops.

Conventionally, this type of automatic start/stop device determines whether or not the engine is rotating when the engine speed is above a certain value (approximately 400 rpm).
This is done by detecting the voltage at the regulator L terminal, whose signal level is determined by the alternator generating electricity.

In other words, when the regulator L terminal is at ground potential, it is determined that the engine is stopped, and if other input signals are appropriate (for example, in the case of a manual transmission vehicle, it is determined that the clutch is depressed by the driver). When the starter motor is automatically started by energizing the starter circuit and the regulator L terminal rises to the battery voltage, it is determined that the engine speed has reached a sufficient value. Then, the power to the starter circuit was cut off and the starter motor stopped operating.

However, if the alternator stops generating electricity due to a failure of the regulator L terminal, etc., or a break in the drive belt that guides engine rotation to the alternator, and the regulator L terminal is at ground voltage even though the engine is rotating, the engine When the starter motor was determined to be stopped, the starter motor was automatically energized and the starter motor was driven, which was dangerous and also resulted in the vehicle being unable to operate.

The present invention has been made in response to the above-mentioned problems, and is based on majority logic for detecting signals of at least three parameters: engine rotation speed, generator output state, and engine oil pressure, for detecting operation or non-operation of an automobile engine. Through the judgment, it is possible to accurately determine which parameter is abnormal, and if the abnormality judgment continues for a predetermined period of time, automatic start/stop control is inhibited to prevent malfunctions such as starter energization while the engine is running, thereby increasing safety. It is intended to increase.

An embodiment of the present invention will be described below with reference to the drawings. In FIG.
The starter and ignition circuit are shown, and the starter 11 is connected to the ignition switch 13.
It is connected to the DC power supply 10 via. When the ignition switch 13 is operated to temporarily connect its movable contact 13a to the fixed terminal 13c, the starter 11 is supplied with power from the DC power source 10 and starts, putting the engine in a cranking state. . The ignition circuit 12 includes a control circuit 12a connected to a signal generator provided in a distributor of the engine, and an ignition coil 12c connected to the control circuit 12a via a transistor 12b. . Under the control of control circuit 12a, transistor 12b becomes conductive in response to generation of a signal from the signal generator and becomes non-conductive in response to disappearance of the signal from the signal generator. In other words, transistor 1
2b generates a collector signal (having a high voltage) each time it becomes non-conductive, the period of this collector signal corresponding to the signal period from the signal generator, that is, the engine speed. The ignition coil 12c is in a state where it can receive power from the DC power supply 10, and is energized in response to the conduction of the transistor 12b, and is cut off from the energized state in response to the non-conduction of the transistor 12b, generating a spark and a high voltage. Grant to triviewer.

The alternator 14 is connected between the DC power supply 10 and the regulator relay 15, and when driven by the engine, generates an AC voltage at the neutral point N of the stator coil and converts this into a DC voltage. and supplies it to the DC power supply 10. The regulator relay 15 is connected to an electromagnetic coil 15a connected between the neutral point N of the stator coil of the alternator 14 and a ground terminal 15c, and to a fixed end terminal 15d connected to the ground terminal 15c or the DC power supply 10. A double-headed contact 15b is provided. However,
When the electromagnetic coil 15a is in a demagnetized state, the double-headed contact 15b is connected to the ground terminal 15c and generates a low voltage Lo from the output terminal L. Electromagnetic coil 15a
is excited by the alternating current voltage generated at the neutral point N of the stator coil, the double-headed contact 15b connects to the fixed terminal 1
5d to generate a high voltage i from the output terminal L.

The microcomputer 20 includes a regulator relay 15, a speed sensor 16, and a set switch 1.
7. Collector of transistors of first clutch switch 18a, second clutch switch 18b and door switches 19, 12b, oil pressure switch 3
5. The speed sensor 16 is composed of a disk 16a made of a permanent magnet and a reed switch 16b arranged to form a magnetic relationship with each protrusion of the disk 16a.
6a is attached to a speedometer drive cable 16c connected to the output shaft of the power transmission device of the vehicle. When the disc 16a rotates in conjunction with the drive cable 16c, the reed switch 16b sequentially detects each protrusion on the disc 16a and generates a series of speed pulses corresponding to the actual running speed of the vehicle.

The set switch 17 is a normally open switch with a self-resetting function, and is provided at a suitable location in the vehicle interior of the vehicle. Thus, this set switch 17 generates a set signal by its temporary closure. First and second clutch switch 18a
and 18b are both provided on the clutch pedal of the vehicle, and the first clutch switch 18a
is of the normally open type and generates the first clutch signal when the clutch pedal is fully depressed. The second clutch switch 18b is of a normally closed type, and
When the clutch pedal is depressed, a second clutch signal is generated, and when the clutch pedal is released, the second clutch signal is extinguished. The door switch 19 is a normally closed switch, which is installed on the door of the vehicle, generates a door signal when the door is opened, and extinguishes this door signal when the door is closed.

The oil pressure switch 35 turns OFF and outputs a Hi signal when the engine oil pressure is above a certain value, and turns ON and outputs a Lo signal when the oil pressure is below a certain value. In other words, when the engine oil is in the required amount for the engine,
When the engine is rotating (normally about 500 rpm or more), the oil pressure switch 35 outputs a Hi signal, and when the engine is stopped (about 100 rpm or less), the oil pressure switch 35 outputs a Lo signal.

The microcomputer 20 is formed by an LSI, and is activated in response to the constant voltage (5V) generated from the constant voltage circuit 21 by power supply from the DC power supply 10 when the ignition switch 13 is closed. Become. The microcomputer 20 includes a central processing unit (hereinafter referred to as CPU), an input/output device (hereinafter referred to as I/O), a read-only memory (hereinafter referred to as ROM), and a random access memory (hereinafter referred to as RAM). ) and a clock circuit are provided, and these CPU, I/O, ROM,
The RAM and clock circuits are connected to each other via bus lines. I/O is transistor 12
Collector signal from b, oil pressure switch 35
Ground signal (low voltage Lo) or open signal (considered high voltage Hi) from 7 Self-diagnosis wiring 3 described later
8 ground signal or open signal regulator relay 1
5, each speed pulse from the speed sensor 16, the set signal from the set switch 17, and the first and second clutch signals from the first and second clutch switches 18a, 18b. and upon receiving the door signal from the door switch 19.
Grant to RAM. The clock circuit is connected to a crystal oscillator 22 and cooperates with the crystal oscillator 22 to generate a series of clock signals.
The ROM stores in advance a main control program and an interrupt control program necessary for the CPU to execute the flowcharts shown in FIGS. 2 and 3, respectively.

The CPU has an interrupt timer, and this interrupt timer starts measuring time at the same time as the microcomputer starts, and when the measured value reaches 1 msec,
The clock will be reset and start counting again. However,
The CPU executes the main control program in response to a series of clock signals from the clock circuit.
Every time the measured value of the interrupt timer reaches 1 msec, execution of the main control program is stopped and the interrupt control program is executed, and by alternately executing both control programs, various calculation processes are performed as described below. At the same time, generation of a drive signal (or drive stop signal) necessary to drive (or stop) the starter 11 and an energization signal (or energization stop signal) necessary to energize (or stop energizing) the ignition coil 12c. bring. in this case,
The execution of the main control program by the CPU is repeatedly completed within 10 msec after its start.

A starter relay 32 and an ignition relay 34 are connected to the microcomputer 20 via transistors 31 and 33, respectively. The light bulb 36 is also connected to the I/O of the microcomputer 20. The transistor 31 is
At that base, the microcomputer 20's I/
It is connected to the fixed terminal 13b of the ignition switch 13 at its emitter, and conducts when it receives a drive signal from the CPU when the ignition switch 13 is closed.
It becomes non-conductive upon receiving a drive stop signal from. The transistor 33 has its emitter grounded and its base connected to the I/O, becomes non-conductive upon receiving a energization signal from the CPU, and becomes conductive upon receiving a energization stop signal from the CPU.

The starter relay 32 has an electromagnetic coil 32a and a normally open contact 32b, and the electromagnetic coil 32a is grounded at one end and the transistor 3 at the other end.
When the transistor 31 is conductive, it is excited by receiving power from the DC power source 10, and is demagnetized in response to the transistor 31 being non-conductive. The normally open contact 32b of the starter relay 32 is connected between the DC power supply 10 and the starter 11, and closes in response to the excitation of the electromagnetic coil 32a, allowing power to be supplied from the DC power supply 10 to the starter 11. Start. In addition, the normally open contact 32b opens in response to demagnetization of the electromagnetic coil 32a to cut off the power supply to the starter 11 and stop it. The ignition relay 34 consists of an electromagnetic coil 34a and a normally closed contact 34b.The electromagnetic coil 34a is connected between the fixed terminal 13b of the ignition switch 13 and the collector of the transistor 33, and is in a demagnetized state when the transistor 33 is non-conducting. Also, in response to conduction of the transistor 33, it receives power from the DC power supply 10 and is excited. The normally closed contact 34b closes when the electromagnetic coil 34a is in a demagnetized state to allow the DC power supply 10 to supply power to the ignition coil 12c, and opens in response to excitation of the electromagnetic coil 34a to supply power to the ignition coil 12c. cut off.

Further, the light bulb 36 is connected so as to be turned on or off according to an output signal from the microcomputer 20. Further, the signal of the transistor 12b for calculating the engine rotation speed by the microcomputer is input as 37 to the microcomputer 20, and the microcomputer 20 counts the period of the output signal generated when the transistor 12b is non-conductive. It has a configuration that allows calculation of engine rotation speed.

In addition, by connecting the wiring 38 to the body of the vehicle for diagnosing the failure of this device (for example, faulty wiring with the vehicle), the device operates in a failure diagnosis mode as described later. This wiring 38 is provided at a location where it is easy for a service person or the like to ground the body.

In this embodiment configured as described above, when the ignition switch 13 is operated to connect the movable contact 13a to the fixed terminal 13b while the vehicle is stopped, the constant voltage circuit 21 Power is supplied from the power supply 10 to generate a constant voltage, and in response to this, the microcomputer 20 becomes operational. At the same time, the CPU's interrupt timer starts counting, and the CPU starts executing the main control program in step 40 according to the flowcharts of FIGS. 2A, 2B, and 2C. Then, the ignition switch 13 connects the movable contact 13a to the fixed terminal 1.
3c, the starter 11 receives power from the DC power supply 10 and starts the engine in cooperation with the ignition circuit 12. At this time, regulator relay 15 generates high voltage HU under the control of alternator 14. It is assumed that the reed switch 16b is closed due to the magnetic relationship with the disc 16a when the vehicle is stopped.

In this state, when the main control program proceeds to step 41, the CPU initializes the contents of the microcomputer 20, resets the flag F _S , resets the flag F _N , resets the flag F _OIL , and resets the flag F _REG . , reset the flag F _IG , then clear G _OIL , G _REG , C _IG , and C for time counting, advance the main control program to step 42, and check whether the self-diagnosis wiring 38 is grounded to the body. Discern. If the body is in contact with the ground at this time, the process advances to step 43 where flag _FN is set.
If the wiring 38 is open, the process proceeds to step 44 with the flag _FN remaining reset.

In the flowcharts shown in FIGS. 2A, 2B, and 2C, after executing step 41, steps 44 and 1
00 etc. and returns to step 41 again, the microcomputer 20 temporarily suspends the processing every time an interrupt occurs every 1 msec, performs the interrupt processing, and counts the interrupt processing 10 times. Inside
Obtain 10msec by counting in RAM,
After executing step 41, the process is controlled so that the time for returning to step 41 and re-executing it is set every 10 msec. The interrupt processing performs input processing that should be performed quickly in terms of time (for example, processing for calculating vehicle speed or engine rotation speed, such as speed signal 16b and ignition coil ignition signal 12b).

When the process proceeds to step 44, since the flag _FN has not been set, the determination is NO and the process proceeds to step 45. The flag F _OIL is an abnormality determination flag that will be described later.
It is reset when no abnormality is detected.
Now, step 45 determines NO, and step 4
Proceeding to step 6, the flag F _REG is determined to be an abnormality determination flag similar to the flag F _OIL , and it is determined NO, and the process advances to step 47, where the flag F _IG is also determined to be an abnormality determination flag similar to the flag F _OIL.
This is an abnormality determination flag similar to that shown in _FIG .

The flag F _S indicates that the conditions for setting the engine under automatic start/stop control are satisfied, and the setting conditions are set by the regulator relay 15.
The above three requirements are met: the door is generating a high voltage Hi, the door signal from the door switch 19 has disappeared (the door is closed), and the set switch is generating a set signal. It is established by simultaneous establishment.

That is, since the flag F _S is reset in step 48, the process proceeds to step 49, and when the above three requirements are met, the process proceeds to step 50, where the flag F _S is set and the engine is set under automatic start/stop control. become. On the other hand, if the flag F _S is set in step 48, the process proceeds to step 60, where it is determined whether the cancel condition, that is, the condition for resetting the flag F _S for setting the engine under automatic start/stop control, is satisfied. This is a determination, and when this step 60 is satisfied, the cancellation condition is satisfied when either the door signal from the door switch 19 is generated (the door is opened) or the set switch 17 is pressed. Then select Yes and proceed to step 70.
The flag F _S is reset, and in the next step 71, an output signal is output to the transistor 31 so as to cut off the power supply to the starter 11. Next, step 72
Then, the signal is outputted to the transistor 33 to supply power to the ignition coil 12c.

On the other hand, to explain the operation when the engine is under automatic start/stop control when the flag F _S is set, the main control program that has proceeded to step 51 detects that there is no signal from the speed sensor 16 for more than 2 seconds ( A software counter inside the microcomputer 20 recognizes that the vehicle is stopped, and when the clutch is not depressed based on the state of the second clutch switch 18b, an engine stop condition is established, and the process proceeds to step 52. An output is sent to the transistor 33 to stop the power supply to the ignition coil 12c. However, step 5
If it is not satisfied that there is no signal from the speed sensor 16 for more than 2 seconds in step 1, or if the signal from the second clutch switch 18b is detected, or if the clutch is being depressed, the determination is NO and the step continues. 6
1, and outputs to the transistor 33 to energize the ignition coil 12c.

Thus, the process proceeds to step 53, where it is determined whether or not the starter drive condition is satisfied.
When the result is Yes, the signal from the first clutch switch 18a is depressed by the clutch, and the L terminal of the regulator relay 15 is at Lo potential (ground potential).
If this condition is satisfied at the time , the process proceeds to step 54 , and the starter motor 11 is energized by outputting the current to the transistor 31 .

On the other hand, when the result in step 53 is NO, the signal from the first clutch switch 18a is either when the clutch is not depressed or when the L terminal of the regulator relay 15 is at Hi potential (high potential). If this condition is satisfied, in step 55, the transistor 31 stops the power supply to the starter motor 11.
This is done by outputting to .

As explained above, in the automatic engine start/stop control, a determination as to whether or not to place the engine under automatic start/stop control and automatic start/stop output control are executed. However, in such a device, when the engine is under automatic start/stop control, when the regulator relay 15 fails, etc., for example, the L terminal potential is
When only the Lo potential is output, the determination in step 53 is Yes if the output of the first clutch switch establishes a signal indicating that the clutch is depressed, and in step 54, the starter motor 11 is driven. The following is a control program that prevents damage to the gear (not shown) between the starter motor 11 and the engine, which would hinder the operation of the vehicle. . Step 1 after execution of steps 54 or 55 or 72 described above
At step 00, the ignition coil 12c is not de-energized; at step 101, two seconds or more have elapsed since it was switched from de-energized to energized; and at step 102, a drive signal to the starter motor 11 is being generated. When the following conditions are met in step 103: the drive stop signal to the starter motor 11 continues for 2 seconds or more, the process proceeds to step 104.

If the conditions determined from step 100 to step 103 are reversed, the process proceeds to step 105. In this case, the signal from the L terminal of the regulator relay 15, the oil pressure switch 35, and the ignition coil ignition signal 37, which are the signals to be compared with the L terminal of the regulator relay 15, are used for the engine. This is to stop abnormality determination when the motor is stopped or rotating.

Further, in the determination at step 104, if the engine speed obtained from the ignition coil ignition signal is 50 rpm or more and less than 650 rpm, the process proceeds to step 105 to prohibit abnormality determination,
The process is executed up to step 107. This is to reset the time integration counter at the time of abnormality detection using the RAM in the microcomputer 20 that performs abnormality determination.

The necessity of prohibiting these abnormality determinations is such that the ignition coil ignition signal 37 for obtaining the engine speed can be stably obtained, and the unstable state of the engine in which the starter motor 11 is being driven is eliminated. This is because an erroneous determination will be made if the abnormality determination is not made only for the state in which the output state of the L terminal of the regulator relay 15 and the state of the oil pressure switch 35 can be reliably defined depending on the engine speed.

Step 105 from steps 100 to 104
No judgment is made to proceed to step 10, and the judgment at step 104 is that the engine rotation speed is less than 50 rpm, and step 10 is executed.
8, the engine is stopped, so the L terminal of the regulator relay 15 is determined to be Lo, and the process proceeds to step 19, where the oil pressure switch 35 is set to Lo.
When it is determined that the L terminal signal of the regulator relay 15 and the signal of the oil pressure switch 35 should be present when the engine is stopped, each signal logic is determined to be normal.

Similarly, in step 104, the engine speed is
If the speed is 650rpm or more, the judgment in step 111 is Hi.
Then, the process proceeds to step 112, where it is determined that the engine should be rotating even when the signal is determined to be Hi, and that each signal logic is normal, and the process proceeds to step 105.

Based on the determination results in step 108 and step 111, steps 109, 110, 112,
If step 105 is not reached through step 113, the route is based on the engine speed and regulator relay 15.
This is when the three signal logics of the L terminal and the oil pressure switch 35 become abnormal.

In other words, step 1 when the engine is stopped
If the determination in step 08 is Lo and the determination in step 109 is Hi, only the oil pressure switch 35 is outputting an output signal that should be present during engine rotation, so the process proceeds to step 114, and the internal nRAM of the microcomputer 20 records the output signal in the time counter. , passes through the path to be counted, and the time CNT based on the number of times this path is passed every 10 ms, that is, steps 114, 1
When the number of times through 15 becomes 2 seconds or more, the answer is Yes in step 114, the flag F _OIL is set in step 116, and it is recognized that an abnormality is certain. (The need for this 2 second counter is due to the fact that each of the three signals mentioned above can be caused by a momentary (several milliseconds) contact failure of the connector, a response delay of the L terminal of the regulator relay 15 and the oil pressure switch 35, and (This is to take into account chattering of the contacts, response delay due to oil pressure and engine speed, etc.) After step 112, the process advances to step 114.
When an abnormality in the oil pressure switch 35 is detected, the signal logic of the other two of the three signals, that is, the L terminal signal of the regulator relay 15 and the ignition coil ignition signal 37, indicates that the engine is stopped. Since the signals match, the time counters for determining the abnormality of the two are reset in steps 117 and 118.

Similar determinations are made in the following control programs, that is, in the determination of step 108, determination of step 110, determination of step 111, and determination of step 112, which of the three signals is detected when the engine is rotating or stopped. When a discrepancy occurs between one party and the desired signal, the other party detects an abnormality and
By counting the 2 second counters, when each counter reaches 2 seconds, the flag F _OIL ,
Steps 114 to 128 are controls in which F _REG and _FIG are set and abnormalities are recognized.

The control program that has passed through any of steps 117, 118, 123, and 128 is
Go to 0. The determination at step 130 is based on the flag F _N
This is a determination as to whether or not it is a reset. If the flag F _N is set, the judgment at the first step 42 of the flowchart is Yes, and step 43 is executed. This means that the self-diagnosis wiring 38 is grounded, and the process proceeds to step 131. The self-diagnosis result will then be displayed using the light bulb 36.

On the other hand, when the determination at step 130 is NO, that is, when the self-diagnosis mode is not in effect, it is determined at step 135 whether or not the flag F _S is set.
The light bulb 36 is turned on to clearly indicate to the driver that the engine is under automatic start/stop control, and if the flag F _S has been reset, the light bulb 36 is turned off in step 137.

Reset the explanation and select Yes in step 130.
If it is determined that
If the flag _FOIL has been set, the result is YES and the process proceeds to step 138; if the flag _FOIL has been reset, the result is NO and the process proceeds to step 132. In step 132, if the flag F _REG is set, the result is YES, and the process proceeds to step 139; if the flag F _REG has been reset, the result is NO, and the process proceeds to step 133. In step 133, the flag
If the flag F _IG is set, the result is Yes, and the process proceeds to step 140. If the flag F _IG is reset, the process proceeds to step 134. Step 131
This logical judgment is a logical output that outputs the content of the self-diagnosis to the light bulb 36, and in step 134, the internal RAM of the microcomputer 20 is used as a time counter to control the blinking operation of the light bulb 36 as shown in FIG. is used and output.

The output of step 134 indicates that F _OIL , F _REG , and F _IG are all in the reset state, that is, no abnormality has been recognized, so the light bulb 36 is turned on every 2 seconds as shown in Figure 3a.
Lights up for 0.5 seconds to let you know that it is in normal condition.

On the other hand, in an abnormal state where either F _OIL , F _REG , or _FIG is set, steps 45, 46, and 4 are performed.
7, why is it impossible for the driver to put the engine into a state where automatic start/stop is performed because the flag F _S is reset and automatic engine start/stop control is prohibited (i.e., when the light bulb 36 is reset)? In response to this question, an automobile serviceman or the like uses the self-diagnosis wiring 38 to output signals as shown in FIG. The reason for the abnormality can be known, making it easier to discover failures.

As mentioned above, in the automatic engine start/stop device, when the L terminal output cannot operate normally due to a failure of the regulator relay 12 used to automatically start the engine, etc. , In order to prevent the risk of the automatic engine start erroneously operating, the relationship between the three signals of the L terminal of the regulator relay 12, the ignition coil ignition signal 37, and the oil switch 35 is determined to be abnormal. When the automatic start/stop device of the engine is set under the control of the automatic start/stop device, this is canceled and the automatic start/stop device of the engine is prohibited from being set. This can be prevented in advance, and by grounding the self-diagnosis wiring of the light bulb 36, which normally indicates whether or not it is set under automatic start/stop control, it is not possible to set the engine under automatic start/stop control. It is possible to provide a safe and convenient device that can also be used to display the cause.

In addition, in the above embodiment, in step 104, the engine rotation speed is defined as 50 rpm and 650 rpm, but the engine speed is not limited to this and may be changed as appropriate. Also, although steps 114, 119, and 124 were set to 2 seconds, due to the characteristics of the engine,
It may be longer than 1 second to 2 seconds.

In the above embodiment, the ignition coil ignition signal 37 and the regulator relay 15 are input signals that can determine whether the engine is stopped or running.
Although the L terminal and the oil pressure switch 35 are used, the present invention is not limited to this. For example, a sensor for detecting the engine rotation may be provided separately to replace the signals from the three above, or an implementation method may be implemented in which the sensor is added. .

Further, in the above embodiment, steps 138, 1
39,140 output method flags are F _OIL , F _REG ,
If two or more F _IGs are set, the display may display the type corresponding to the abnormal output shown in FIG.

Further, in the above embodiment, an example in which the present invention is applied to an automobile gasoline engine has been described, but the present invention is not limited to this, and the present invention can also be applied to an automobile diesel engine. Therefore, in this case, instead of the ignition circuit 12, a fuel injection control circuit for controlling the amount of fuel injected into the diesel engine is adopted, and this fuel injection control circuit is connected to the normally closed contact 34b of the ignition relay 34.
Fuel injection may be stopped when the valve opens.

At that time, the ignition coil ignition signal 37
Instead, a pick-up coil sensor or the like may be used to detect the engine speed.

As described above, in the present invention, at least three parameters, engine speed, generator output state, and engine oil pressure, are used to detect engine operation or non-operation for controlling the stop and automatic start of an automobile engine. Not only is it possible to accurately determine which parameter is abnormal by detecting the operating status of the detection signal and determining which parameter is abnormal by majority logic judgment of the detection signal, but also prevents automatic control from then on in the event of an abnormality to ensure safety such as starter protection. It has the excellent effect of improving

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention;
2A, 2B, and 2C are flowcharts showing the arithmetic processing of the microcomputer, and FIGS. 3a, b, c, and d are waveform diagrams for explaining the operation. 11...Starter, 12...Ignition circuit,
17...Set switch, 20...Microcomputer, 35...Oil pressure switch, 36...Light bulb,
38...Wiring for self-diagnosis.

Claims (1)

[Scope of Claims] 1. An automatic starting/stopping method for an automobile engine that stops the operation of the engine when the automobile stops, and detects the starting operation when the automobile starts and energizes the starter to automatically start the engine. , which detects engine operation or non-operation, detects the operation status of at least three parameters: engine speed, generator output status, and engine oil pressure, and determines which parameter is abnormal by majority logic judgment of the detection signal. A method for automatically starting and stopping an automobile engine, characterized in that the automatic starting and stopping control for an automobile engine is prohibited when an abnormality determination continues for a predetermined period of time or more.