JP5874445B2 - Abnormality diagnosis device - Google Patents

Description

  The present invention relates to an abnormality diagnosis apparatus for an ECU (electronic control unit) that controls to supply power to a starter motor based on a start request signal for automatically starting an engine.

  A general engine is configured such that when a drive signal is input to a starter relay, the starter relay is turned on to supply power to the starter motor, and cranking is started by driving the starter motor.

  In the case of the idle stop system, the microcomputer determines the automatic start conditions such as the vehicle speed, the accelerator, the brake, and the like, and if it determines that the automatic start conditions are satisfied, it requests that the engine be automatically started. A start request signal is output. When the start request signal is input to the drive circuit, the drive circuit outputs the drive signal described above to the starter relay (see Patent Documents 1 and 2).

JP 2011-179398 A JP 2010-90874 A

  However, when a start request signal is transmitted from the microcomputer to the drive circuit, an error such as a sign error occurs in the start request signal on the communication line, the drive circuit is broken, or there are disconnections or short circuits in various lines. There are various factors that make it impossible to output the drive signal normally, such as the occurrence of the drive signal. Thus, since the drive signal output to the starter motor may have a different content from the start request signal, means for enabling on-board diagnosis whether or not the drive signal can be output normally is provided. This is necessary for a vehicle having a function of automatically starting the engine.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an on-board abnormality diagnosis device that can diagnose whether or not a drive signal to a starter motor can be normally output. There is.

Inventions that to achieve the above object is characterized by the following points. That is, when the engine is automatically started, a start request signal including a plus side start request signal and a minus side start request signal is output . When the engine is not automatically started, a plus side start request signal is included and a minus side start request signal is output. Request signal output means for sequentially switching and outputting a first pseudo request signal not including a positive start request signal and a second pseudo request signal including a negative start request signal ;
An electromagnetic relay that contacts the movable contact with the fixed contact by the magnetic force of the electromagnetic coil, and when the positive drive signal is given to the plus side of the electromagnetic coil and the minus drive signal is given to the minus side, the movable contact Switch means (20) for contacting the fixed contact to enable power supply to the starter motor (12);
When a positive start request signal is given by any one of the start request signal from the request signal output means, the first pseudo request signal, and the second pseudo request signal, the positive side of the electromagnetic coil of the switch means is positive. A drive signal output means (70, 70A, 71, 72) for outputting a drive signal and outputting a minus drive signal to the minus side of the electromagnetic coil when a minus side start request signal is given ;
Inconsistency abnormality in which the drive signal output means does not output the plus side drive signal even though the plus side start request signal is given from the request signal output means, and the minus side start request signal is given from the request signal output means Diagnostic means (53, S12) for diagnosing whether or not there is a misalignment abnormality in which the drive signal output means does not output the minus side drive signal in spite of being provided,
The diagnosis means is realized by the microcomputer (50) executing the program stored in the memory. The diagnosis means is provided outside the microcomputer, and an area where the program of the diagnosis means is stored in the storage area of the memory. A monitoring IC (82) for sequentially checking whether or not a failure has occurred,
Without the starter motor being driven by the first pseudo request signal and the second pseudo request signal, the misalignment abnormality between the plus side start request signal and the plus side drive signal, and the minus side start request signal and the minus side drive signal It is possible to diagnose an inconsistency abnormality .

  Here, if the above-mentioned start request signal error, drive circuit failure, disconnection in various lines, short circuit, etc. occur, the content of the start request signal and the content of the drive signal will not match. . For example, a mismatch may occur in that a drive signal is output even though a start request signal is not output, or a drive signal is not output although a start request signal is output. In the above-mentioned invention in view of this point, the start request signal and the drive signal are acquired, and it is diagnosed whether or not the two signals are mismatched. Therefore, whether or not the drive signal to the starter motor can be normally output. Can be diagnosed on-board.

  In addition, when the request signal output means, the drive signal output means, and the diagnosis means are accommodated in the same casing to constitute an ECU (electronic control unit), the drive signal is acquired inside the ECU according to the above invention. it can. Therefore, when acquiring a drive signal from the outside of the ECU, a harness for transmitting the drive signal is required, but the harness can be made unnecessary in the above invention.

  Here, when the mismatch described above occurs in the start request signal and the drive signal, the start request signal and the engine output signal also mismatch. That is, although the start request signal is not output, the drive signal is output and the starter motor is driven, and the engine output changes. Alternatively, although the start request signal is output, the drive signal is not output and cranking start cannot be performed. In the above invention in view of this point, the start request signal and the engine output signal are acquired, and it is diagnosed whether or not the two signals are inconsistent, so whether the drive signal to the starter motor can be normally output. Whether or not can be diagnosed on-board.

  In addition, when the request signal output means, the drive signal output means, and the diagnosis means are accommodated in the same casing to constitute an ECU (electronic control unit), the drive signal is acquired inside the ECU according to the above invention. it can. Therefore, when acquiring a drive signal from the outside of the ECU, a harness for transmitting the drive signal is required, but the harness can be made unnecessary in the above invention.

The block diagram which shows the structure of ECU concerning 1st Embodiment of this invention. The flowchart which shows the diagnostic procedure of ECU in 1st Embodiment. The flowchart which shows the procedure of the normal check diagnosis of a forced stop function in 1st Embodiment. The block diagram which shows the structure of ECU concerning 2nd Embodiment of this invention. The flowchart which shows the procedure of the normal check diagnosis of a forced stop function in 2nd Embodiment. The block diagram which shows the structure of ECU concerning 3rd Embodiment of this invention.

  Embodiments of an abnormality diagnosis apparatus according to the present invention will be described below with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other are denoted by the same reference numerals in the drawings, and the description of the same reference numerals is used.

(First embodiment)
A starter device 10 shown in FIG. 1 starts cranking a traveling engine mounted on a vehicle, and includes an electromagnetic solenoid 11 that pushes a pinion gear (not shown) and an electric motor 12 that rotates the pinion gear. The pinion gear meshes with a ring gear that rotates together with the engine output shaft, and transmits the driving force of the electric motor 12 to the ring gear. When the electromagnetic solenoid 11 is energized, it is pushed out to a position that meshes with the ring gear.

  The starter relay 20 is switch means for switching on / off the power supply from the battery power supply 30 to the starter device 10, and includes a movable contact 21, a fixed contact 21 a, and an electromagnetic coil 22. When a drive signal to be described later is input from the ECU 40 to the electromagnetic coil 22, the movable contact 21 is attracted by the magnetic force of the electromagnetic coil 22 and comes into contact with the fixed contact 21a. Thereby, electric power is supplied from the battery power source 30 to the electric motor 12 and the electromagnetic solenoid 11.

  The ECU 40 (electronic control unit) is configured by accommodating a microcomputer (microcomputer 50), an integrated IC 60 (drive signal output means), and a starter driver IC 70, which will be described later, in the same casing. In each storage area of the memory (ROM) constituting the microcomputer 50, an engine start control unit 51, a starter relay drive instruction unit 52 (request signal output means), a consistency monitor 53, a forced cut instruction unit 54 (stop signal output) Means) and a check unit 55 are written. These are programs that execute various processes described below.

  The engine start control unit 51 determines whether the vehicle speed, the accelerator, the brake, and the like satisfy the automatic start condition or the automatic stop condition. When it is determined that the automatic stop condition is satisfied, the engine is automatically stopped, for example, by stopping fuel injection from the fuel injection valve. On the other hand, when it is determined that the automatic start condition is satisfied, the starter device 10 is operated and fuel injection is started to automatically start the engine. Thereby, the function of an idle stop system (ISS) is exhibited.

  The starter relay drive instructing unit 52 outputs a start request signal when the engine start control unit 51 determines that the automatic start condition is satisfied. This start request signal is a signal that commands energization to each of the plus terminal 22a (high voltage side terminal) and the minus terminal 22b (ground side terminal) of the electromagnetic coil 22. When both terminals 22a and 22b are energized and turned on due to the output of the start request signal, the electromagnetic coil 22 of the starter relay 20 is energized and both the contacts 21 and 21a are turned on to supply power to the starter device 10. The Rukoto.

  The start request signal output from the starter relay drive instructing unit 52 is transmitted from the microcomputer 50 to the integrated IC 60 by serial communication through the communication line L1. That is, the start request signal (plus side start request signal) for the plus terminal 22a and the start request signal (minus side start request signal) for the minus terminal 22b are transmitted by one communication line L1.

  The integrated IC 60 divides the start request signal output from the microcomputer 50 into a plus start request signal and a minus start request signal, and outputs each start request signal to the starter driver IC 70 through separate lines L2 and L3.

  The starter driver IC 70 includes a high side driver (HSD 71), a low side driver (LSD 72), a diagnosis (Diag 73), and a serial peripheral interface (SPI 74) described below.

  The HSD 71 is a switch means that is turned on when a plus-side start request signal is input, and the LSD 72 is a switch means that is turned on when a minus-side start request signal is input. In the example of FIG. 1, FET transistors are employed for the HSD 71 and the LSD 72, and when a voltage of a start request signal is applied to the gate terminal, a current flows between the source and drain terminals. Thus, each of the HSD 71 and the LSD 72 outputs a drive signal (plus side drive signal) for the plus terminal 22a and a drive signal (minus side drive signal) for the minus terminal 22b.

  The plus side drive signal outputted from the HSD 71 through the line L4 is outputted from the external port 41 of the ECU 40 to the plus terminal 22a of the electromagnetic coil 22. Further, the minus side drive signal outputted from the LSD 72 through the line L5 is outputted from the external port 42 of the ECU 40 to the minus terminal 22b of the electromagnetic coil 22. Therefore, the starter device 10 operates only when the both terminals 22a and 22b of the electromagnetic coil 22 are energized, and the starter device 10 does not operate only by energizing one terminal. In short, on the condition that both the plus side drive signal accompanying the output of the plus side start request signal and the minus side drive signal accompanying the output of the minus side start request signal are normally input to the electromagnetic coil 22, the starter The device 10 is driven. Therefore, even if one of the plus side drive signal and the minus side drive signal is abnormal (single failure), the starter device 10 is not driven against the intention of the driver.

  The SPI 74 acquires each drive signal output from the HSD 71 and LSD 72 and immediately before being output from the external ports 41 and 42. Also, the diagnosis result of the starter driver IC 70 by the Diag 73 and a forced stop signal described later are acquired. These signals are transmitted from the SPI 74 to the microcomputer 50 by serial communication through the communication line L6. That is, the plus side drive signal and the minus side drive signal are transmitted through one communication line L6. The forced stop signal is input to the forced cut instruction unit 54.

  The consistency monitor 53 (diagnostic means) of the microcomputer 50 acquires the plus side drive signal and the minus side drive signal output from the SPI 74, and the plus side start request signal and minus side output from the starter relay drive instruction unit 52. A start request signal is acquired. Then, the obtained start request signal is compared with the drive signal, and the consistency is checked on both the plus side and the minus side. For example, if the drive signal is not output even though the start request signal is output, or if the drive signal is output even if the start request signal is not output, there is a mismatch. Determine that there is, and diagnose that an abnormality has occurred.

  Specific examples of the cause of this abnormality include a communication error (for example, a sign error in the start request signal) in the communication line L1, a failure in the microcomputer 50, a failure in the integrated IC, a failure in the starter driver IC 70, various lines L2, L3, and L4. , Disconnection at L5, short circuit, and the like.

  When an abnormality is diagnosed by the consistency monitor 53, a forced stop signal is output from the forced cut instruction unit 54 to the starter driver IC 70. When the forced stop signal is input, the starter driver IC 70 forcibly stops the output of the drive signal even when the start request signal is input from the integrated IC 60. A line L7 (forced stop communication line) for transmitting a forced stop signal from the forced cut instruction unit 54 to the starter driver IC 70 is provided separately from the communication line L1 (request communication line) for transmitting a start request signal. Yes.

  The monitoring IC 81 sequentially checks whether or not the area including the engine start control unit 51 and the starter relay drive instruction unit 52 in the memory area of the microcomputer 50 has a hardware failure. The monitoring IC 82 sequentially checks whether or not the area including the consistency monitor 53 and the forced cut instruction unit 54 in the memory area of the microcomputer 50 has a hardware failure. Note that the check unit 55 of the microcomputer 50 is a means for checking whether or not data is garbled in a specific area of the memory of the microcomputer 50. The consistency monitor 53 and the forced cut instruction unit 54 are provided in this specific area.

  The consistency monitor 53, the monitoring ICs 81 and 82, and the Diag 73 described in detail above diagnose whether the ECU 40 is abnormal. According to the diagnosis of the monitoring ICs 81 and 82 and the Diag 73, although the hardware failure of the starter driver IC 70 and the microcomputer 50 can be diagnosed, the data garble and disconnection in the various lines L1 to L5 cannot be diagnosed. This type of abnormality (abnormalities in various lines L1 to L5) can be diagnosed by the consistency monitor 53.

  Next, the procedure of diagnosis by the consistency monitor 53 and the forced stop by the forced cut instruction unit 54 will be described with reference to FIG. 2 is repeatedly executed by the microcomputer 50 at a predetermined cycle.

  First, in step S10 of FIG. 2, it is determined whether or not the diagnostic results by the monitoring ICs 81 and 82 and the Diag 73 are normal. If it is determined that it is not normal (S10: NO), ECU 40 diagnoses that it is abnormal in step S16 described later. On the other hand, if it is determined to be normal (S10: YES), in the next step S11, it is determined whether or not it is at the time of automatic start by ISS. If it is determined that it is an automatic start time (S11: YES), in the next step S12, the start request signal and the drive signal are compared by the consistency monitor 53, and the consistency is checked.

  If it is determined that they are consistent (S12: YES), the ECU 40 diagnoses that it is normal in the next step S13. On the other hand, if it is determined that they are not matched (S12: NO), the ECU 40 diagnoses that there is an abnormality in the next step S16. In subsequent step S <b> 17, the forced cut instruction unit 54 outputs a forced stop signal to the starter driver IC 70. In the next step S18, the operation of the ISS is stopped. That is, the automatic stop and automatic start of the engine are prohibited.

  If it is determined in the above-described step S11 that it is not at the time of automatic start by ISS (S11: NO), the starter relay drive instructing unit 52 transmits a pseudo request signal described below to the integrated IC 60 through serial communication via the communication line L1. Send.

  The pseudo request signal is for enabling diagnosis by the consistency monitor 53 without driving the starter device 10. Specifically, the first pseudo request signal for stopping the output of the minus side start request signal while outputting the plus side start request signal, and the output of the plus side start request signal being stopped while outputting the minus side start request signal. The second pseudo request signal is a signal configured by sequentially switching. In addition, the timing for sequentially switching the first and second pseudo request signals is set to an irregular timing. For example, switching of both pseudo request signals at a predetermined time interval is prohibited. In addition, switching of both pseudo request signals in a regular predetermined pattern is prohibited.

  Accordingly, the starter driver IC 70 outputs a positive drive signal when the first pseudo request signal is output, and outputs a negative drive signal when the second pseudo request signal is output. In subsequent step S15, the consistency monitor 53 compares the pseudo request signal with the drive signal to check the consistency. For example, when the plus side start request signal is output, the plus side drive signal is not output, or when the minus side start request signal is output, the minus side drive signal is output. When there is no drive signal is output even though these start request signals are not output, it is determined that there is a mismatch.

  If it is determined that they are consistent (S15: YES), ECU 40 diagnoses that it is normal in step S13. On the other hand, if it is determined that they are not matched (S15: NO), the ECU 40 diagnoses an abnormality in step S16, outputs a forced stop signal (S17), and stops the operation of the ISS (S18).

  Since the connection between the starter relay 20 and the ECU 40 has a duplex structure as described above, the starter relay 20 is not turned on even if one of the plus side start request signal and the minus side start request signal is output. The starter device 10 is not driven. Therefore, diagnosis by the consistency monitor 53 becomes possible without driving the starter device 10. That is, the diagnosis by the consistency monitor 53 can be sequentially performed during engine operation.

  According to the procedure shown in FIG. 3, the starter relay drive instructing unit 52 outputs the above-described forced stop signal on a trial basis and checks whether the forced stop by the forced stop signal functions normally. Note that the processing in FIG. 3 is repeatedly executed by the microcomputer 50 at a predetermined cycle, or at least once per trip.

  First, in step S30 in FIG. 3, it is determined whether or not the forced stop signal may be output on a trial basis. Specifically, if it is diagnosed as normal in step S13 described above and the engine is not being started, the test output of the forced stop signal is permitted (S30: YES), and the subsequent step S31 (normal operation confirmation means) The forced stop signal is output to the starter driver IC 70. In the subsequent step S32 (normal operation confirmation means), it is determined whether or not the forced stop signal output from the test is returned from the SPI 74 to the forced cut instruction unit 54. If there is a return input of the forced stop signal (S32: YES), the forced stop function is diagnosed as normal (S33). If there is no return input of the forced stop signal (S32: NO), the forced stop function is abnormal. A diagnosis is made (S34).

  As described above, according to the present embodiment, the following effects are exhibited.

  Since the microcomputer 50 acquires the start request signal and the drive signal and diagnoses whether or not both signals are mismatched, it is determined whether or not the drive signal to the starter device 10 can be normally output. Diagnose on board. And since a drive signal is acquired inside ECU40, the harness required when acquiring the drive signal output from the external ports 41 and 42 of ECU40 from ECU exterior can be made unnecessary.

  -When an abnormality is diagnosed due to inconsistency, a forced stop signal is output from the forced cut instruction unit 54, and the starter driver IC 70 forcibly outputs a drive signal when the forced stop signal is input. Stop. Therefore, when it is diagnosed as abnormal, it is possible to reliably avoid driving the starter device 10 by outputting a drive signal against the driver's intention.

  In addition to the communication line L1 (request communication line) that transmits a start request signal to the starter driver IC 70, a line L7 (forced stop communication line) that transmits a forced stop signal is provided. Therefore, when an abnormality is diagnosed due to the abnormality of the communication line L1, the forced stop signal can be transmitted using the line L7 different from the communication line L1 in the abnormal state. Therefore, when the abnormality is diagnosed, the starter device 10 can be reliably prevented from being driven against the intention.

  When it is diagnosed as normal, a forced stop signal is output from the microcomputer 50 to the starter driver IC 70 as a test, and it is determined whether or not the forced stop signal is returned from the starter driver IC 70 to the microcomputer 50. Therefore, it can be confirmed whether or not the output forced stop signal is normally input to the starter driver IC 70, and when the abnormality is diagnosed, the starter device 10 is surely driven unintentionally. Can be avoided.

  The connection between the starter relay 20 and the ECU 40 has a duplex structure, and outputs a pseudo request signal that outputs one of the plus side start request signal and the minus side start request signal when the engine is not actually started. Therefore, the diagnosis by the consistency monitor 53 can be sequentially performed without driving the starter device 10.

  The pseudo request signal is configured by sequentially switching a first pseudo request signal for outputting only the plus side start request signal and a second pseudo request signal for outputting only the minus side start request signal. Therefore, it is possible to diagnose whether there is an abnormality in both the lines L2 and L4 related to the plus side start request signal and the lines L3 and L5 related to the minus side start request signal.

  Here, for example, when serial communication is performed on the communication line L1, if an abnormality that causes data corruption occurs in a predetermined cycle, if the cycle of the switching timing coincides with the data corruption cycle, an abnormality due to data corruption occurs. May be overlooked. In this embodiment in view of this point, the timing of sequential switching of the first and second pseudo request signals is set to an irregular timing. Therefore, the probability that the switching timing cycle and the data conversion cycle coincide with each other as described above can be reduced, and the possibility of overlooking a data conversion abnormality can be reduced.

  Here, when the ECU 40 is diagnosed as abnormal, there is a high possibility that the automatic start and stop cannot be normally performed normally. Therefore, in the present embodiment, when an abnormality is diagnosed, the ISS function is stopped, and the automatic stop and automatic start of the engine are prohibited. For this reason, it is possible to reliably avoid problems such as automatic stop in a situation where automatic start is not possible, or automatic stop against the driver's intention.

(Second Embodiment)
As shown in FIG. 4, the starter driver IC 70 </ b> A according to the present embodiment has a configuration in which the SPI 74 according to the first embodiment is abolished. Therefore, dedicated lines L6a and L6b for transmitting drive signals from the starter driver IC 70A to the consistency monitor 53 are provided. These lines L6a and L6b are connected so as to branch from the lines L4 and L5 that connect the starter driver IC 70A and the external ports 41 and 42.

  In the case of the present embodiment, the communication line L6 (see FIG. 1) for returning the test-output forced stop signal from the starter driver IC 70A to the microcomputer 50 is not provided. Therefore, in the case of this embodiment, it is desirable to confirm whether or not the output forced stop signal is normally input to the starter driver IC 70 by the procedure shown in FIG.

  That is, first, in steps S30 and S31 in FIG. 5, a forced stop signal is experimentally output in the same manner as in steps S30 and S31 in FIG. In the subsequent step S31a (normal operation confirmation means), a positive start request signal and a negative start request signal are alternately output to the HSD 71 and the LSD 72. In the subsequent step S32a (normal operation confirmation means), it is determined whether or not a drive signal is output from the starter driver IC 70A.

  Here, if the forced stop signal is normally output to the starter driver IC 70A and functions, the drive signal is not output even if the start request signal is output. Therefore, the starter driver IC 70A to the microcomputer 50 through the lines L6a and L6b. The drive signal should not be input. In this embodiment focusing on this point, if it is determined in step S32a that a drive signal is output (S32a: YES), the forced stop function is diagnosed as abnormal (S34), and no drive signal is output. If determined (S32a: NO), the forced stop function is diagnosed as normal (S33).

  In addition, in the output of the start request signal in step S31a, it implements alternately to HSD71 and LSD72, and the connection of the starter relay 20 and ECU40 has a double structure as mentioned above. Therefore, even if the forced stop function is abnormal, it can be avoided that the starter device 10 is driven by the output of the start request signal in step S31a.

(Third embodiment)
In the first embodiment, the HSD 71 and the LSD 72 are configured by one IC (starter driver IC 70A). However, in the present embodiment, the HSD 71 and the LSD 72 are configured by a single component as shown in FIG. Therefore, dedicated lines L7a and L7b for transmitting a forced stop signal to each of the HSD 71 and LSD 72 are provided.

  These lines L7a and L7b are provided with switching means 83 and 84 using transistors or the like. When a forced stop signal is input from the microcomputer 80 to the switch means 83 and 84, the switch means 83 and 84 are turned on and output a forced stop signal to the HSD 71 and LSD 72. As a result, the output of drive signals from the HSD 71 and LSD 72 is forcibly stopped. Also in this embodiment, it is desirable to confirm whether or not the output forced stop signal is normally input to the HSD 71 and LSD 72 by the same method as in FIG.

(Fourth embodiment)
In each of the above embodiments, the consistency monitor 53 checks the consistency between the start request signal and the drive signal. On the other hand, the consistency monitor 53 (diagnosis unit) according to the present embodiment acquires an engine output or a physical quantity correlated with the engine output (hereinafter referred to as “engine output signal”) instead of the drive signal. Specific examples of the engine output signal include the rotational speed NE of the engine output shaft (crankshaft), the pressure in the combustion chamber (cylinder pressure), and the like.

  Then, the consistency between the engine output signal and the start request signal is checked. That is, for example, at the time of automatic start by ISS, if the engine speed NE does not increase despite the output of the start request signal, it is determined that there is no consistency. When the engine is stopped, if the engine speed NE rises even though the start request signal is not output, it is determined that there is no consistency (see the one-dot chain line in FIG. 2).

  If it is determined that there is no consistency in the determination indicated by the alternate long and short dash line in FIG. 2 (S12a: NO), it is diagnosed that the ECU 40 may be abnormal (S16). On the other hand, if it is determined that there is consistency (S12a: YES), the ECU 40 diagnoses it as normal (S13). However, in the present embodiment, even if a pseudo request signal is output, the engine output signal that is the subject of consistency does not change, and therefore diagnosis by the output of the pseudo request signal cannot be performed.

(Other embodiments)
The present invention is not limited to the description of the above embodiment, and may be modified as follows. Moreover, you may make it combine the characteristic structure of each embodiment arbitrarily, respectively.

  The starter relay 20 (switch means) according to each of the above embodiments may be replaced with a semiconductor switch such as a power MOS.

  DESCRIPTION OF SYMBOLS 12 ... Starter motor, 20 ... Starter relay (switch means), 52 ... Starter relay drive instruction | indication part (request signal output means), 53 ... Consistency monitor (diagnosis means), 70, 70A, 71, 72 ... Starter driver IC ( Drive signal output means), S12, S12a ... diagnostic means

Claims (6)

When the engine is automatically started, a start request signal including a plus side start request signal and a minus side start request signal is output . When the engine is not automatically started, the plus side start request signal is included, and the minus side start request signal is included. Request signal output means (52) for sequentially switching and outputting a first pseudo request signal that does not include a signal and a second pseudo request signal that does not include the plus side start request signal and includes the minus side start request signal ;
An electromagnetic relay that contacts a movable contact with a fixed contact by the magnetic force of an electromagnetic coil, wherein when a positive drive signal is given to the plus side of the electromagnetic coil and a minus drive signal is given to the minus side, Switch means (20) enabling a power supply to the starter motor (12) with a movable contact contacting the fixed contact;
When the plus side start request signal is given by any one of the start request signal, the first pseudo request signal, and the second pseudo request signal from the request signal output means, the electromagnetic of the switch means Drive signal output means (70, 70A) that outputs the plus side drive signal to the plus side of the coil and outputs the minus side drive signal to the minus side of the electromagnetic coil when the minus side start request signal is given. 71, 72),
Inconsistency abnormality in which the drive signal output means does not output the plus drive signal despite the plus side start request signal being given from the request signal output means, and the minus from the request signal output means Diagnosing means (53, S12) for diagnosing whether or not a misalignment abnormality has occurred in which the drive signal output means does not output the minus side drive signal despite the side start request signal being given ;
With
The diagnostic means is realized by the microcomputer (50) executing a program stored in the memory,
A monitoring IC (82) that is provided outside the microcomputer and sequentially checks whether or not an area in which the program of the diagnostic means is stored in the storage area of the memory is faulty;
Due to the first pseudo request signal and the second pseudo request signal, mismatching abnormality between the plus side start request signal and the plus side drive signal without driving the starter motor, and the minus side start request signal An abnormality diagnosis apparatus characterized in that it is possible to diagnose an inconsistency abnormality between the negative drive signal and the minus side drive signal . A stop signal output means (54) for outputting a forced stop signal when an abnormality is diagnosed by the diagnosis means;
The abnormality diagnosis according to claim 1, wherein the drive signal output means forcibly stops the output of the plus side drive signal and the minus side drive signal when the forced stop signal is input. apparatus.   In addition to the request communication line (L1) for transmitting the start request signal to the drive signal output means, a forced stop communication line (L7) for transmitting the forced stop signal to the drive signal output means is provided. The abnormality diagnosis device according to claim 2.   Normal operation confirmation means for confirming whether or not the forced stop signal is normally input to the drive signal output means by outputting the forced stop signal on a trial basis when the diagnosis means has diagnosed normality The abnormality diagnosis apparatus according to claim 2, further comprising (S31, S32, S31a, S32a).   The abnormality diagnosis device according to claim 1, wherein the sequential switching timing is set to an irregular timing.   6. The abnormality diagnosis apparatus according to claim 1, wherein when the abnormality is diagnosed by the diagnosis unit, automatic engine stop and automatic start are prohibited.

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