JP2003247450A - Abnormality diagnosing apparatus for rotation angle sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately make a judgement whether a rotation angle sensor is normal or abnormal. <P>SOLUTION: An abnormality diagnosing apparatus for a rotation angle sensor makes a judgement that a crank angle sensor 16 is abnormal when the number of occurrences of a crank angle NE signal detected by the crank angle sensor 16 within one rotation of a camshaft 12 based on the number of occurrences of a cam angle G signal detected by a cam angle sensor 19, i.e., within two rotations of a crankshaft 10. The number of occurrences of the crank angle NE signal by the crank angle sensor 16 can be set larger than the number of occurrences of the cam angle G signal by the cam angle sensor 19. Therefore, if a line on the negative side of the crank angle sensor 16 is disconnected, the number of occurrences of the crank NE signal becomes largely lower than a specified range. If a line on the positive side of the crank angle sensor 16 is disconnected, the number of occurrences of the crank angle NE signal becomes zero. Thus, an accurate judgement that the crank angle sensor 16 is abnormal can be made. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation angle sensor abnormality diagnosing device for detecting a signal generated corresponding to a rotation angle of a rotary shaft that rotates in synchronization with a piston motion of an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, as a prior art document related to a rotation angle sensor abnormality diagnosing device, Japanese Patent Laid-Open No. 8-189409 is known.
Japanese Patent Publication No. 4-53329, Japanese Patent Publication No. 27435.
The one disclosed in Japanese Patent Publication No. 79 is known.

Among them, Japanese Patent Laid-Open No. 8-189409 discloses a crank angle sensor which outputs a crank angle NE signal corresponding to the rotation of a crankshaft of an internal combustion engine and a cam angle generated corresponding to a reference position of the crankshaft. The minus (ground) line with the cam angle sensor (reference position sensor) that outputs the G signal is shared and connected. When this minus line is disconnected, the cam angle G signal from the cam angle sensor is converted into the crank angle sensor. A technique for performing an abnormality diagnosis when the crank angle NE signal from is superposed is shown. In this case, if the signal interval of the cam angle G signal becomes short, the crank angle N
The diagnosis for the E signal is prohibited, and the cam angle G is added to the missing tooth signal interval of the crank angle NE signal.
It is said that the cam angle G signal abnormality diagnosis is carried out depending on how many signals are generated.

Further, in Japanese Patent Publication No. 4-5329, the counting of the crank angle NE signal output from the crank angle sensor is started by the cam angle G signal output from the cam angle sensor, regardless of the generation of the cam angle G signal. A technique for counting the crank angle NE signal output until a predetermined value is reached, and diagnosing a cam angle G signal abnormality based on the presence or absence of the cam angle G signal output when the count value of the crank angle NE signal output matches the predetermined value. It is shown. In this case, when the current interval in the cam angle G signal is longer than the previous interval, it is determined that the cam angle G signal is abnormal, and conversely when it is short, it is determined that the crank angle NE signal is abnormal.

In Japanese Patent No. 2473579, the count of the crank angle NE signal from the crank angle sensor is reset every time the cam angle G signal is output from the cam angle sensor, and the elapsed time from the input of the cam angle G signal is reset. The cam angle G signal input time interval is measured, the crank angle NE signal count value is equal to or greater than a predetermined value, and the elapsed time from the cam angle G signal input is the latest of the cam angle G signal input time interval. When it is longer than the predetermined time determined by the value of, the cam angle sensor is determined to be abnormal, and the count value of the cam angle G signal is equal to or greater than the predetermined value
Further, there is disclosed a technique of determining that the crank angle sensor is abnormal when the elapsed time from the input of the cam angle G signal is shorter than the predetermined time.

[0006]

By the way, in the crank angle NE signal waveform from the crank angle sensor, when the negative line is broken, the signal is squeezed on the circuit, and becomes an abnormal crank angle NE signal waveform, which is on the plus line side. Appears in. Here, in FIG. 5A, the signal generation interval is 10 [° CA (Crank
Angle: crank angle)] shows a normal crank angle NE signal waveform before waveform shaping, and FIG. 5B shows an abnormal crank angle NE signal waveform when the negative line is broken. In this abnormal crank angle NE signal waveform, the signal generation interval becomes long and the number of signals is about 1/2 to 1/3 of the normal crank angle NE signal waveform.

Then, in the technique according to the above-mentioned Japanese Patent Laid-Open No. 8-189409, the abnormal crank angle NE signal waveform shown in FIG. 5 (b) is different from the normal crank angle NE signal waveform shown in FIG. 5 (a). Therefore, if the signal generation interval is long, there is a problem that the cam angle sensor is regarded as abnormal despite the abnormality of the crank angle sensor.

In the technique disclosed in Japanese Patent Publication No. 4-5329, the normal crank angle NE shown in FIG.
In contrast to the signal waveform, if the abnormal crank angle NE signal waveform shown in FIG. 5B is generated and the signal generation interval is long, the count value does not reach a predetermined value or more, which makes it impossible to determine. there were.

In the technique according to the above-mentioned Japanese Patent No. 2734579, an abnormal crank angle NE signal waveform shown in FIG. 5 (b) is obtained in contrast to the normal crank angle NE signal waveform shown in FIG. 5 (a). If the signal generation interval is long, the cam angle G signal is always counted until the count value reaches a predetermined value, and it is determined that the crank angle sensor is normal even if it is abnormal. was there.

Therefore, the present invention has been made to solve such a problem, and an object thereof is to provide an abnormality diagnosis device for a rotation angle sensor capable of accurately determining whether the rotation angle sensor is normal or abnormal.

[0011]

According to the abnormality diagnosis device for a rotation angle sensor of the first aspect, a predetermined rotation angle of a first rotation shaft that rotates in synchronization with a piston movement of an internal combustion engine is determined. The first signal generated in number and the second signal generated in a predetermined number corresponding to a predetermined rotation angle of the second rotation shaft are different in the number generated in the same period, and are different from the first signal. Two signals are set to be generated more.
Therefore, the second signal detected by the second rotation angle sensor within the period from the detection of the first signal by the first rotation angle sensor until the detection of the predetermined number of first signals. Are counted and the second number of signals within this period causes a second
Normal / abnormal of the rotation angle sensor is determined. In this way, by using the highly reliable first signal detected by the first rotation angle sensor as the first rotation shaft rotates, the normality / abnormality of the second rotation angle sensor is determined. Is accurately determined.

In the rotation angle sensor abnormality diagnosis device according to the second aspect, the first rotation shaft is the cam shaft of the internal combustion engine, the first rotation angle sensor is the cam angle sensor, and the second rotation shaft is Since the crankshaft is the crankshaft of the internal combustion engine, and the second rotation angle sensor is the crank angle sensor, the crankshaft has two crankshafts corresponding to one rotation of the camshaft set by the number of signals detected by the cam angle sensor. The number of signals generated during the period of rotation is detected by the crank angle sensor. As a result, the reference signal is limited to the cam angle signal from the highly reliable cam angle sensor, and the number of signals detected by the crank angle sensor should be set larger than the number of signals detected by the cam angle sensor. Thus, the accuracy of normal / abnormal detection of the crank angle sensor is improved.

In the abnormality detecting device for a rotation angle sensor according to a third aspect of the present invention, the abnormality detecting means determines whether the second rotation angle sensor is normal / abnormal while the internal combustion engine is being driven by the starter control means. As a result, when the second rotation angle sensor is abnormal, the backup signal of the second signal can be quickly created, and the operating state of the internal combustion engine immediately after starting is stabilized.

In the abnormality diagnosing means in the abnormality diagnosing device for the rotation angle sensor according to the fourth aspect, the crank angle sensor detects the abnormality within a period associated with one rotation of the cam shaft based on the first signal number detected by the cam angle sensor. The crank angle sensor is determined to be abnormal when the second signal count is not within the predetermined range. Here, since the second signal number detected by the crank angle sensor can be set larger than the first signal number detected by the cam angle sensor, it is possible to accurately determine whether the crank angle sensor is normal or abnormal. it can.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below based on Examples.

FIG. 1 is a schematic block diagram showing an internal combustion engine and its peripheral equipment to which an abnormality diagnosis device for a rotation angle sensor according to an embodiment of the present invention is applied.

In FIG. 1, the internal combustion engine 1 includes an intake passage 2
And the exhaust passage 3 is connected. Of these, a throttle valve 4 which is driven by the depression amount of an accelerator pedal (not shown) is arranged in the intake passage 2. Also,
An injector (fuel injection valve) 5 for injecting and supplying fuel to each cylinder of the internal combustion engine 1 is provided. An ignition plug 6 is provided in each cylinder of the internal combustion engine 1,
The spark plug 6 is connected to a distributor 8 that distributes the high voltage supplied from the igniter 7 and supplies the high voltage to the spark plug 6 of each cylinder.

The air that has passed through the throttle valve 4 is mixed with the fuel injected by the injector 5 to form a mixture, which is introduced into each cylinder. Then, a high voltage from the igniter 7 is supplied to the spark plug 6 via the distributor 8, and the spark ignition of the spark plug 6 causes the air-fuel mixture in each cylinder to be ignited and burned at a predetermined timing.

An air flow meter 2 for detecting an intake air amount (intake air amount) QA is further provided around the internal combustion engine 1.
1, a water temperature sensor 22 for detecting the cooling water temperature THW,
An A / F sensor 23 or the like for detecting the A / F (air-fuel ratio) λ based on the oxygen concentration contained in the exhaust gas is provided, and sensor signals from these various sensors are E
CU (Electronic Control Unit) 3
It is input to 0.

The crankshaft 10 is connected to the connecting rod 9 of the main body of the internal combustion engine 1 and is shown in another position in FIG. 1 for the sake of convenience. The rotation of the crankshaft 10 is transmitted via the timing belt 11 to the two camshafts 12 and 13 for intake and exhaust. Here, the sprocket tooth number ratio between the crankshaft 10 and the camshafts 12, 13 is 1: 2, and when the crankshaft 10 makes two revolutions, the camshafts 12, 13 make one revolution.

A crank signal rotor 14 is fixedly mounted on the crank shaft 10. The crank signal rotor 14 has an outer periphery of only one location at an interval of 30 ° CA, and the others are at one.
Tooth portion 1 is provided at 34 (36-2) points at 0 [° CA] intervals.
5 is formed. This crank signal rotor 14
A magnet pickup type crank angle sensor 16 is disposed at a position facing the outer periphery of the. A cam signal rotor 17 is fixed to one of the cam shafts 12, and tooth portions 18 are formed on the outer periphery of the cam signal rotor 17 at four positions corresponding to a predetermined crank angle. . A magnet pickup type cam angle sensor (reference position detection sensor) 19 is provided at a position facing the outer periphery of the cam signal rotor 17.

In other words, the crank angle sensor 16 outputs an AC signal accompanying the passage of the tooth portion 15 at intervals of 10 [° CA] according to the rotation of the crank shaft 10 (however, only 30 [° CA] at one location), and the cam is output. The angle sensor 19 outputs an AC signal accompanying the passage of the tooth portion 18 at four positions at predetermined intervals as the cam shaft 12 rotates. These sensor signal outputs are input to the ECU 30.

The ECU 30 includes a CPU as a central processing unit for executing various well-known arithmetic processes, a ROM storing control programs and the like, a RAM storing various data, and a B / U.
It is configured as a logical operation circuit including a (backup) RAM, an input / output circuit, and a bus line connecting them. In this ECU 30, a predetermined crank angle position of the crankshaft 10 is generated based on a crank angle NE signal generated every 10 [° CA] based on a signal read from the crank angle sensor 16 and a signal read from the cam angle sensor 19. The cam angle G signal generated in response to the above is generated.

Then, the ECU 30 uses the crank angle NE signal, the cam angle G signal and the sensor signals from the air flow meter 21, water temperature sensor 22, oxygen sensor 23, etc., which are various other sensors, to inject the fuel injection amount TAU by the injector 5. The ignition timing Ig by the spark plug 6 is controlled.

Next, E used in the abnormality diagnosis device for the rotation angle sensor according to the first example of the embodiment of the present invention.
Based on the flowchart of FIG. 2 showing the processing procedure of the normal / abnormal determination of the crank angle sensor 16 in the CU 30, it will be described with reference to FIG. 5 described above. It should be noted that this normality / abnormality determination routine is executed at every cam angle G signal interruption, that is, at 720 [° C.
A] is repeatedly executed by the ECU 30 four times.

In FIG. 2, in step S101, the value of the cam tooth number counter A is incremented by "+1". The cam tooth number counter A is an internal counter for avoiding a malfunction caused immediately after the internal combustion engine 1 is cranked by a starter (not shown). Next, the process proceeds to step S102, and the value of the cam tooth number counter B is "+".
1 ”is incremented. This cam tooth counter B
Is an internal counter for detecting one revolution of the cam shaft 12. Next, the process proceeds to step S103, and it is determined whether the value of the cam tooth number counter B is equal to "5". When the determination condition of step S103 is satisfied, that is, when the value of the cam tooth number counter B at this time is “4 (the number of cam angle G signal generation for one rotation of the cam shaft 12) +1”, step S1
The routine proceeds to 04, and the value of the crank angle signal counter at this time by the routine described later is stored in the crank angle signal holding memory.

That is, the value of the crank angle signal counter is
When the normal crank angle NE signal waveform shown in FIG. 5 (a) is output from the crank angle sensor 16, the camshaft 12 is incremented by “+1” every 10 [° CA] except for the toothless portion. 1 revolution of the internal combustion engine 1
It should be "68" at 720 [° CA] corresponding to the combustion cycle. On the other hand, as for the value of the crank angle signal counter, the abnormal crank angle NE signal waveform with a long signal generation interval shown in FIG.
Is output from 720 [° corresponding to one rotation of the camshaft 12, that is, one combustion cycle of the internal combustion engine 1.
It should be less than half of "68" in [CA].
As described above, in this embodiment, the normality / abnormality of the crank angle sensor 16 is determined by utilizing the difference in the generation intervals of the signal waveforms of the normal crank angle NE signal waveform and the abnormal crank angle NE signal waveform. is there.

Next, in step S105, the value of the crank angle signal counter is cleared to "0". Next, the process proceeds to step S106, and the value of the cam tooth number counter B is returned to "1 (initial value)".

Next, the routine proceeds to step S107, where it is judged if the monitor permission flag is set by the routine described later. When the determination condition of step S107 is satisfied, that is, when the monitor permission flag is set, the process proceeds to step S108, and it is determined whether the crank angle signal holding memory value is in the range of "63 to 73". The determination condition of step S108 is satisfied, that is, the crank angle signal holding memory value stored in the crank angle signal holding memory in step S104 is “68 {= (36-2) × 2}; one combustion cycle of the internal combustion engine 1”. Is within the range of “63 to 73 (= 68 ± 5)” in which noise superposition is taken into consideration with respect to “the number of crank angle NE signal generation for two rotations of the crankshaft 10”, the process proceeds to step S109 The normality determination process for the angle sensor 16 is executed, and this routine ends. In this normality determination process, for example, the crank angle signal holding memory value is "6" last time due to noise superposition or the like.
If the fail counter is incremented outside the range of 3 to 73 ", the value of the fail counter is cleared to" 0 ".

On the other hand, when the determination condition of step S108 is not satisfied, that is, the crank angle signal holding memory value stored in the crank angle signal holding memory in step S104 is not within the range of "63 to 73", step S110.
The value of the fail counter is incremented by "+1". Next, the process proceeds to step S111, and it is determined whether the value of the fail counter at this time exceeds "5". The determination condition of step S111 is satisfied, that is,
If the value of the fail counter is larger than "5" and the number of crank angle NE signals generated is not within the range of "63 to 73", the process proceeds to step S112 to determine whether the crank angle sensor 16 is abnormal. The processing is executed, and this routine ends. In this abnormality determination process,
Diagnosis is performed and a warning is given to the driver that the sensor is abnormal.

On the other hand, the determination condition of step S103 is not satisfied, that is, when the value of the cam tooth number counter B at this time is not "5", or the determination condition of step S107 is not satisfied, that is, the monitor permission flag. Is not set, or the determination condition of step S111 is not satisfied, that is, when the value of the fail counter is smaller than "5", it is determined that the abnormality determination of the crank angle sensor 16 has not been finalized, and this routine ends. To do.

Next, E used in the abnormality diagnosis device for the rotation angle sensor according to the first example of the embodiment of the present invention.
The process procedure of setting the monitor permission flag in the CU 30 will be described with reference to the flowchart of FIG. The monitor permission flag setting routine is repeatedly executed by the ECU 30 every 32 [ms: millisecond].

In FIG. 3, in step S201, it is determined whether cranking is in progress. When the determination condition of step S201 is satisfied, that is, when the internal combustion engine 1 is cranking, the process proceeds to step S202, and it is determined whether the value of the cam tooth number counter A exceeds "2". The cam tooth number counter A is set in order to prevent erroneous detection of the cam angle sensor 19 due to the disturbance of the generation state of the cam angle G signal immediately after starting due to cranking of the internal combustion engine 1 and the fluctuation of the battery voltage. . The determination condition of step S202 is satisfied, that is, the value of the cam tooth number counter A is larger than "2", and the malfunction of the camshaft 1 can be avoided immediately after the start.
When the rotation of 2 is advancing, the process proceeds to step S203, the monitor permission flag is set, and this routine ends.

On the other hand, when the determination condition of step S201 is not satisfied, that is, when the internal combustion engine 1 is not cranking,
Alternatively, the determination condition of step S202 is not satisfied, that is,
When the value of the cam tooth number counter A is as small as "2" or less and the rotation of the cam shaft 12 is not advanced before the malfunction immediately after the start can be avoided, the process proceeds to step S204. In step S204, the monitor permission flag is reset.
Next, the process proceeds to step S205, the value of the fail counter is cleared to "0", and this routine ends.

Next, E used in the abnormality diagnosis apparatus for the rotation angle sensor according to the first example of the embodiment of the present invention.
The crank angle signal counter setting processing procedure in the CU 30 will be described with reference to the flowchart of FIG. The crank angle signal counter setting routine is repeatedly executed by the ECU 30 every time the crank angle NE signal is interrupted.

In FIG. 4, the value of the crank angle signal counter is incremented by "+1" in step S301,
This routine ends. The value of the crank angle signal counter is determined by the crank angle NE signal generated by the crank angle sensor 16 in accordance with the rotation of the crank shaft 10, that is, the crank signal rotor 14 fixed to the crank shaft 10.
Corresponds to the tooth part 15 excluding the toothless part on the outer circumference of 10 [° CA]
It is incremented by "+1" each time.

As described above, the abnormality diagnosis device for the rotation angle sensor according to the present embodiment includes the first rotation shaft arranged to rotate in synchronization with the piston movement of the internal combustion engine 1 and the piston movement of the internal combustion engine 1. A second rotation angle sensor for detecting a first signal generated in a predetermined number corresponding to a predetermined rotation angle of the second rotation shaft and the first rotation shaft arranged to rotate in synchronization with And a second rotation angle sensor for detecting a second signal generated by a predetermined number corresponding to a predetermined rotation angle of the second rotation shaft, and the first signal detected by the first rotation angle sensor. Within a period until a predetermined number of first signals are detected after
An abnormality achieved by the ECU 30 that counts the second signal detected by the second rotation angle sensor and determines normality / abnormality of the second rotation angle sensor based on the counted second number of signals. And diagnostic means.

That is, a predetermined number of first signals and a predetermined rotation of the second rotary shaft are generated corresponding to a predetermined rotation angle of the first rotary shaft that rotates in synchronization with the piston motion of the internal combustion engine 1. The number of generated second signals is different from the number of generated second signals corresponding to the angle, and the second signal is set to be generated more than the first signal. Therefore, the second signal detected by the second rotation angle sensor within the period from the detection of the first signal by the first rotation angle sensor until the detection of the predetermined number of first signals. Is counted, and the normality / abnormality of the second rotation angle sensor is determined by the second signal number within this period. in this way,
The normality / abnormality of the second rotation angle sensor is accurately determined by using the highly reliable first signal detected by the first rotation angle sensor as the first rotation shaft rotates. be able to.

Further, in the abnormality diagnosis device for the rotation angle sensor of this embodiment, the first rotation shaft is the camshaft 12 of the internal combustion engine 1, and the first rotation shaft is the first rotation shaft.
The rotation angle sensor is the cam angle sensor 19, the second rotation axis is the crankshaft 10 of the internal combustion engine 1, and the second rotation angle sensor is the crank angle sensor 16. That is,
"4" cam angle G signals are generated in response to one revolution of the cam shaft 12, and the crank angle corresponds to 720 [° CA] which is two revolutions of the crank shaft 10 which constitutes one combustion cycle of the internal combustion engine 1. "68" NE signals are generated. Therefore, if the crank angle sensor 16 is normal within the period from when the first cam angle G signal is detected by the cam angle sensor 19 to when "4" cam angle G signals are detected, "6"
8 "crank angle NE signals will be detected.

The abnormality diagnosis apparatus for the rotation angle sensor of this embodiment further includes a starter (not shown) for the internal combustion engine 1.
The ECU 30 is provided with a starter control means that is driven by the ECU 30. The abnormality diagnosis means that is achieved by the ECU 30 is executed while the internal combustion engine 1 is being driven by the starter control means. That is, abnormality diagnosis of the crank angle sensor 16 can be executed during cranking in which the internal combustion engine 1 is driven by the starter.
Therefore, when the crank angle sensor 16 is abnormal, the backup signal of the crank angle NE signal can be quickly created,
It is possible to stabilize the operating state immediately after the internal combustion engine 1 is started. Further, the effect of reducing the software load when the internal combustion engine 1 is rotating at high speed can be expected.

The abnormality diagnosing means of the abnormality diagnosing device for the rotation angle sensor of this embodiment uses the camshaft G based on the number "4" of the cam angle G signal, which is the first signal detected by the cam angle sensor 19, as the camshaft. When the camshaft 12 makes one revolution, that is, the crankshaft 10 makes two revolutions, the number of crank angle NE signals, which is the second signal detected by the crank angle sensor 16, is detected. When it is not within the predetermined range of "63 to 73", it is determined that the crank angle sensor 16 is abnormal.

That is, the cam angle G by the cam angle sensor 19
The number of crank angle NE signals generated by the crank angle sensor 16 within the period in which the crankshaft 10 makes two revolutions of 720 [° CA] with one revolution of the camshaft 12 at which the number of signals is "4". Is not within the range of "63 to 73", it can be determined that the crank angle sensor 16 is abnormal. At this time, since the number of crank angle NE signals generated by the crank angle sensor 16 can be set larger than the number of cam angle G signals generated by the cam angle sensor 19, it is possible to accurately determine whether the crank angle sensor 16 is normal or abnormal. You can

Specifically, as described above, due to the disconnection on the minus side of the crank angle sensor 16, the abnormal crank angle N
When the E signal waveform is input, the number of crank angle NE signals generated is far below the range of "63 to 73", and
When the crank angle NE signal cannot be counted at all due to the disconnection of the crank angle sensor 16 on the plus side, the number of occurrences of the crank angle NE signal becomes “0”, and therefore both the crank angle sensor 1
It can be determined that the abnormality is 6.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an internal combustion engine and peripheral equipment to which an abnormality diagnosis device for a rotation angle sensor according to an example of an embodiment of the present invention is applied.

FIG. 2 is an ECU used in an abnormality diagnosis device for a rotation angle sensor according to an example of an embodiment of the present invention.
5 is a flowchart showing a processing procedure of normality / abnormality determination of the crank angle sensor in FIG.

FIG. 3 is an ECU used in an abnormality diagnosis device for a rotation angle sensor according to an example of an embodiment of the present invention.
5 is a flowchart showing a processing procedure for setting a monitor permission flag in FIG.

FIG. 4 is an ECU used in an abnormality diagnosis device for a rotation angle sensor according to an example of an embodiment of the present invention.
5 is a flowchart showing a processing procedure of crank angle signal counter setting in FIG.

FIG. 5 is a waveform diagram showing a normal crank angle signal and an abnormal crank angle signal determined by a rotation angle sensor abnormality diagnosis device according to an example of an embodiment of the present invention.

[Explanation of symbols]

1 Internal combustion engine 10 crankshaft 12 cam shaft 16 crank angle sensor 19 Cam angle sensor 30 ECU (electronic control unit)

Claims (4)

[Claims] 1. A first rotating shaft arranged to rotate in synchronism with a piston movement of an internal combustion engine, and a second rotating shaft arranged to rotate in synchronism with a piston movement of the internal combustion engine. And a first rotation angle sensor for detecting a first signal generated in a predetermined number corresponding to a predetermined rotation angle of the first rotation shaft, and corresponding to a predetermined rotation angle of the second rotation shaft. And a second rotation angle sensor for detecting a second signal generated by a predetermined number, and a predetermined number of the first signals after the first signal is detected by the first rotation angle sensor. The second signal detected by the second rotation angle sensor is counted within a period until it is detected, and the normality of the second rotation angle sensor is determined based on the counted second number of signals. And an abnormality diagnosis means for determining an abnormality. Support of the abnormality diagnosis apparatus. 2. The first rotation shaft is a cam shaft of the internal combustion engine, the first rotation angle sensor is a cam angle sensor, and the second rotation shaft is of the internal combustion engine. The abnormality diagnosis device for a rotation angle sensor according to claim 1, wherein the abnormality sensor is a crankshaft, and the second rotation angle sensor is a crank angle sensor. 3. A starter control means for driving the internal combustion engine by a starter is further provided, and the abnormality diagnosis means is executed while the internal combustion engine is being driven by the starter control means. An abnormality diagnosis device for a rotation angle sensor according to claim 1 or 2. 4. The abnormality diagnosis means detects one rotation of the cam shaft based on the first signal number detected by the cam angle sensor, and the crank angle is detected within a period in which the cam shaft makes one rotation. The abnormality of the rotation angle sensor according to claim 2 or 3, wherein when the second number of signals detected by the sensor is not within a predetermined range, it is determined that the crank angle sensor is abnormal. Diagnostic device.