Fault detection method

Abstract

The normal power terminal (13) is connected to a normal power source (11) mounted on a vehicle. The starting power terminal (23) is connected to a starting power source (21) via a starting switch (22) that is operated to be turned on when the vehicle is started. The CPU (40) is activated by supply of a normal voltage input via the normal power terminal (13). The wake-up circuit (30) has a wake-up switch (32) that opens and closes a power supply path from the normal power terminal (13) to the CPU (40), and turns on the wake-up switch (32) when a starting voltage input to the starting power terminal (23) is equal to or higher than an on threshold. In a case where the normal voltage is equal to or higher than a determination threshold although the starting voltage is lower than the on threshold, the CPU (40) determines that the wake-up switch (32) is stuck on.

Description

[0001] Cross-references to related applications

[0002] This application is based on Japanese Application No. 2021-092321, filed on June 1, 2021, the contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to fault detection methods. Background Technology

[0004] Previously, techniques for detecting fixed faults in power relays installed in power circuits were known. For example, the fault diagnosis device disclosed in Patent Document 1, even after a predetermined time has elapsed after the ignition switch and power relay are turned off, if the capacitor voltage does not drop and the microcomputer is still operational, stores the information indicating a fixed power relay fault in a storage unit. Then, when the ignition switch is turned on again, the microcomputer reads the fault information stored in the storage unit and determines that the power relay has a fixed power relay fault. Furthermore, the power relay in Patent Document 1 is equivalent to the "wake-up switch" in this disclosure.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2010-111311

[0006] In the technology of Patent Document 1, a fault is determined based on the stored content of the storage unit when the system is temporarily stopped, in other words, when the vehicle is restarted after being parked. Therefore, if the stored content changes due to some important factor during the system shutdown, there is a concern that the microcomputer may read incorrect information and make a misjudgment upon restarting. For example, even if the power relay is actually normal, a fault may be mistakenly determined if the stored content changes to the faulty side.

[0007] Furthermore, when resetting the CPU as a fault diagnosis measure, the process involves repeatedly performing actions such as <1> resetting, <2> CPU restarting, <3> mistakenly identifying a fault due to changes in storage content, and <4> resetting... This raises concerns about exceeding the memory write limit and potentially damaging the CPU itself. Summary of the Invention

[0008] The purpose of this disclosure is to provide a fault detection method to prevent misjudgments caused by changes in stored content.

[0009] This disclosure discloses a fault detection method for detecting a fixed fault in the activation of a wake-up switch in an electronic control device that includes a common power supply terminal, a start-up power supply terminal, a CPU, and a wake-up circuit with a wake-up switch.

[0010] The mains power terminal is connected to the mains power supply installed in the vehicle. The starting power terminal is connected to the starting power supply via a starter switch that is activated when the vehicle is started. The CPU starts by receiving the voltage of the mains power supply, i.e., the mains voltage, input through the mains power terminal. The wake-up switch opens and closes the power supply path from the mains power terminal to the CPU. The wake-up circuit activates the wake-up switch when the voltage input to the starting power terminal, i.e., the starting voltage, exceeds the activation threshold.

[0011] In the first embodiment of this disclosure, if the start-up voltage is less than the turn-on threshold but the normal operating voltage is above the determination threshold, the CPU determines that the wake-up switch is in a fixed fault.

[0012] In the second aspect of this disclosure, if the CPU is operating even though the startup voltage is less than the turn-on threshold, the CPU determines that the wake-up switch is in a fixed fault.

[0013] Here, "wake-up switch connection failure" is not limited to a failure where the contacts of the wake-up switch are actually welded. For example, it can be broadly interpreted as including situations where, although the actual starting voltage is less than the connection threshold, the wake-up circuit mistakenly determines that "the starting voltage is above the connection threshold."

[0014] In this disclosure, even if a fixed failure occurs due to the wake-up switch before the system stops, fault information is not stored. The CPU detects faults by monitoring the actual voltage and its own operating state at the current moment. Since fault determination is not based on stored content, false determinations caused by changes in stored content can be prevented. Furthermore, when the CPU is reset as a fault determination measure, repeated reset actions caused by false determinations can be prevented, thus preventing CPU damage caused by exceeding the memory write limit. Attached Figure Description

[0015] While referring to the appendix Figure 1 The above-mentioned objects, as well as other objects, features, and advantages of this disclosure, become clearer through the following detailed description. The accompanying drawings are shown below.

[0016] Figure 1 This is a diagram illustrating a system configuration example of the fault detection method applied in this embodiment.

[0017] Figure 2 It is a timing diagram illustrating the normal operation of the ECU.

[0018] Figure 3 This is a timing diagram illustrating the fault detection method of this embodiment.

[0019] Figure 4This diagram shows the voltage supply status after the IG switch is turned off before the auxiliary battery is removed and after the auxiliary battery is reinstalled.

[0020] Figure 5 This is a diagram showing the voltage off state during the auxiliary battery removal process.

[0021] Figure 6 This is a flowchart of the fault detection method in this embodiment.

[0022] Figure 7 This is a diagram illustrating other system configuration examples of the fault detection method applied in this embodiment.

[0023] Figure 8 This is a diagram illustrating other system configuration examples of the fault detection method applied in this embodiment. Detailed Implementation

[0024] (One implementation method)

[0025] One embodiment of the fault detection method will be described based on the accompanying drawings. First, refer to... Figure 1 The following is a system configuration example of the fault detection method applied in this embodiment. In this system, the electronic control unit (hereinafter referred to as "ECU") 400 uses the power of the auxiliary battery 11 mounted on the vehicle to drive the motor 80 that outputs the steering assist torque of the electric power steering device.

[0026] The ECU400 has an auxiliary battery terminal 13 (“+BB” in the diagram) and an ignition (hereinafter referred to as “IG”) terminal 23 as power input terminals. Figure 1 In the system configuration example shown, auxiliary battery terminal 13 and IG terminal 23 are connected to different power sources. Auxiliary battery terminal 13 is connected, for example, to a 12V auxiliary battery 11. IG terminal 23 is connected to IG battery 21 via IG switch 22. Alternatively, it can be configured as follows... Figure 7 As with other system configuration examples shown, IG terminal 23 is connected to auxiliary battery 11.

[0027] The IG switch 22 mentioned in the implementation description is conceptually a "start switch" that is turned on when the vehicle is started. Correspondingly, the IG battery 21 is a "starting power supply", and the IG terminal 23 is a "starting power supply terminal". In addition, the IG voltage, which is the voltage input to the IG terminal 23 and will be described later, is equivalent to the "starting voltage". Furthermore, in this specification, "starting" is used to refer to the vehicle, and "starting" is used to refer to the CPU.

[0028] Similarly, the auxiliary battery 11 mentioned in the implementation statement is conceptually a "normal power source" that continuously supplies power during system operation. Correspondingly, the auxiliary battery terminal 13 is a "normal power source terminal". In addition, the VS voltage, which is the voltage of the auxiliary battery 11 input to the ECU 400 via the auxiliary battery terminal 13 and will be described later, is equivalent to the "normal voltage".

[0029] The ECU400 includes a power relay 65, a reverse connection protection relay 67, and an inverter circuit 70, serving as a major component of the power system that supplies power to the motor 80. The motor 80 is, for example, a three-phase brushless motor. The inverter circuit 70 operates via switching elements on the upper and lower three-phase arms, converting the DC power from the auxiliary battery 11 into three-phase AC power for output.

[0030] Power relay 65 and reverse connection protection relay 67 are provided on the power line Lp from auxiliary battery terminal 13 to inverter circuit 70. When disconnected, they cut off the connection between auxiliary battery 11 and inverter circuit 70. When power relay 65 and reverse connection protection relay 67 are constructed of MOSFETs, their respective parasitic diodes are configured such that the downstream side (i.e., cathode) faces the midpoint m. Furthermore, midpoint m is connected to control voltage generation unit 39 via intermediate diode 66. In addition, noise filters, smoothing capacitors, current sensors, etc., which are components of the power system, are omitted.

[0031] The ECU 400 includes a wake-up circuit 30, a control voltage generation unit 39, and a CPU 40, forming part of the startup and control systems. The control voltage generation unit 39 generates, for example, a maximum control voltage of 5V based on the VS voltage input from the auxiliary battery terminal 13 and outputs it to the CPU 40. The control voltage generation unit 39 is, for example, constructed using a dedicated custom IC. The CPU 40 is activated by the control voltage supplied from the control voltage generation unit 39 and controls the operation of the ECU 400 through various control calculations.

[0032] As an implementation, strictly speaking, the control voltage is generated by the control voltage generating unit 39 supplied with VS voltage, and the CPU 40 operates based on the control voltage based on VS voltage. However, conceptually, it is possible to include the function of the control voltage generating unit 39 in a part of the "CPU". Therefore, it can also be expressed as "the CPU 40 starts up by the supply of VS voltage". In addition, "the power supply path from the auxiliary battery terminal 13 to the control voltage generating unit 39" can be replaced with "the power supply path from the auxiliary battery terminal 13 to the CPU 40".

[0033] The wake-up circuit 30 includes a wake-up diode 31, a wake-up switch 32, and an IG voltage determination circuit 33. The wake-up switch 32 switches the power supply path from the auxiliary battery terminal 13 to the CPU 40. When the IG switch 22 is on, the IG voltage determination circuit 33 determines whether the input IG voltage is above a threshold. If the IG voltage is above the threshold, the IG voltage determination circuit 33 activates the wake-up switch 32. Alternatively, the wake-up switch 32 and the IG voltage determination circuit 33 can be integrated into a single IC.

[0034] When the wake-up switch 32 is turned on, as shown by the thick solid arrow, current flows from the auxiliary battery terminal 13 through the wake-up switch 32, supplying the VS voltage to the control voltage generation unit 39. This power supply path is referred to as the "first power supply path P1". The wake-up diode 31 prevents the reverse flow of current in the first power supply path P1.

[0035] Furthermore, if the CPU40 turns on the power relay 65 as described later, as shown by the thick dashed arrow, current flows from the auxiliary battery terminal 13 through the power relay 65, supplying the VS voltage to the control voltage generation unit 39. This power supply path is referred to as the "second power supply path P2". The intermediate diode 66 prevents the reverse flow of current in the second power supply path P2.

[0036] Furthermore, an IG voltage monitoring circuit 53 for monitoring the IG voltage and a VS voltage monitoring circuit 54 for monitoring the VS voltage are provided. The CPU 40 acquires the monitored values ​​from the IG voltage monitoring circuit 53 and the VS voltage monitoring circuit 54 to perform a judgment in the fault detection method. In addition, although details are omitted, for example, a boost circuit to compensate for the voltage drop during cranking can be provided between the wake-up circuit 30 and the control voltage generation unit 39.

[0037] Next, refer to Figure 2 The timing diagram illustrates the normal operation of ECU400. From top to bottom, it shows the input voltage to ECU400, the on / off state of IG switch 22, the on / off state of wake-up switch 32, the state of CPU40, and the on / off state of power relay 65. Reverse connection protection relay 67 and power relay 65 are simultaneously on / off, but this is omitted from the following description.

[0038] An example of the input voltage value is shown. The maximum value of both the IG voltage and the VS voltage is 12V. When the IG voltage is above 9V, normal control of the CPU40 can be performed. In this embodiment, normal control refers to the auxiliary operation of the electric power steering system. The minimum IG voltage at which the CPU40 can start is 4V. Furthermore, when the IG voltage decreases, based on the IG voltage monitored by the IG voltage monitoring circuit 53, the maximum IG voltage at which the CPU40 transitions from stop control to power lock is 1.8V.

[0039] During startup, the IG switch 22 is turned on at time t1, and the IG voltage supplied to the IG terminal 23 gradually increases. If the IG voltage reaches 4V at time t2, the IG voltage determination circuit 33 turns on the wake-up switch 32. In this way, a 12V VS voltage is supplied from the auxiliary battery terminal 13 to the control voltage generation unit 39 through the first power supply path P1, and the CPU 40 starts up.

[0040] If the IG voltage monitoring value reaches 9V at time t3, the CPU40 turns on the power relay 65 to start the normal control of the ECU400. After the normal control starts, in addition to the first power supply path P1, the VS voltage is also supplied to the control voltage generation unit 39 through the second power supply path P2.

[0041] At the stop, IG switch 22 is disconnected at time t4, and the IG voltage begins to decrease. If the monitored IG voltage drops to 9V at time t5, the CPU 40 switches from normal control to stop control. If the IG voltage drops to 4V at time t6, the IG voltage determination circuit 33 disconnects the wake-up switch 32. At this time, the first power supply path P1 is cut off, but the supply of VS voltage to the control voltage generation unit 39 continues through the second power supply path P2.

[0042] If the monitored IG voltage drops to 1.8V at time t7, the CPU 40 transitions from stop control to power lock. During power lock, the VS voltage is maintained for a specified period TPL (e.g., ten minutes) to sustain some of the CPU 40's functionality. At time t8, after the specified period TPL has elapsed from time t7, the power lock ends, the CPU 40 disconnects the power relay 65, cutting off the VS voltage supply from the second power supply path P2 to the control voltage generation unit 39. Therefore, the CPU 40 stops operating.

[0043] Based on the system configuration described above, this embodiment assumes a fixed fault condition where the wake-up switch 32 is on. In the prior art of Patent Document 1 (Japanese Patent Application Publication No. 2010-111311), fault determination is based on the stored content of the storage unit, raising concerns about misjudgment when the stored content changes. Even if the wake-up switch 32 is actually functioning normally, a fault may still be misjudged if the stored content changes towards the faulty side. Conversely, even if the wake-up switch 32 is actually faulty, a normal operation may still be misjudged if the stored content changes towards the normal side.

[0044] Furthermore, when resetting the CPU40 as a fault diagnosis measure, the process involves repeatedly performing actions such as <1> reset, <2> CPU restart, <3> mistakenly determining a fault due to changes in storage content, <4> reset, etc. This raises concerns about exceeding the memory write limit and potentially damaging the CPU40 itself. To avoid such problems, this embodiment aims to detect fixed faults in the wake-up switch 32's connection using a fault diagnosis method that is not based on storage content.

[0045] Next, refer to Figures 3-5 The operation of the wake-up circuit 30 and the fault detection method are explained when the wake-up switch 32 is turned on in the event of a fixed fault. Figure 3 In the time series diagram, times t4 to t8 are... Figure 2 The times indicated by the same markings are shown. On the vertical axis, from top to bottom, the auxiliary battery terminal voltage, the on / off state of IG switch 22, IG voltage, VS voltage during fault and normal operation, CPU status, and the on / off state of power relay 65 are shown in sequence.

[0046] The voltages are represented by the values ​​HI and LO. HI is equivalent to... Figure 2 The voltage range is 9V to 12V. For VS voltage after time t10, values ​​above the threshold are processed as HI. The auxiliary battery terminal voltage and the LO of VS voltage are actually equivalent to 0V. The LO of IG voltage refers to the value being less than the turn-on threshold of wake-up switch 32, which is equivalent to less than... Figure 2 4V.

[0047] exist Figure 4 The middle shows Figure 3 The voltage supply status at times t4 to t9, and after time t10. Figure 5 The middle shows Figure 3 The voltage is not supplied during the time intervals t9 to t10. Relative to... Figure 1 The configuration of the ECU400 shown is as follows: Figure 4 , Figure 5 The components not shown in the diagram are not directly related to the fault detection method.

[0048] At time t4, IG switch 22 is disconnected, and at time t5, control transitions to stop. From time t5 to time t6, the IG voltage decreases from HI to LO. During the period from t7 to t8, power locking is performed. Figure 2 As shown, under normal circumstances, at time t6 during stop control, the wake-up switch 32 is disconnected by the IG voltage determination circuit 33, cutting off the first power supply path P1. Additionally, at time t8 when the power lock ends, the supply of the VS voltage is cut off, and the operation of the CPU 40 ceases.

[0049] However, in the event of a fixed fault in the wake-up switch 32, such as Figure 4 As shown, after time t6, the VS voltage continues to be supplied to the control voltage generation unit 39 via the first power supply path P1. Therefore, after time t8 when the power lock ends, the CPU 40 cannot stop and enters a "sleep waiting state". Furthermore, in the prior art of Patent Document 1, a connection failure is detected at this timing, and the failure information is stored in the storage unit.

[0050] At time t9, remove auxiliary battery 11. Figure 5 As shown, the connection between the auxiliary battery 11 and the auxiliary battery terminal 13 is cut off, so even if the wake-up switch 32 is turned on due to a fixed fault, the VS voltage is not supplied from the auxiliary battery terminal 13 to the control voltage generation unit 39. Therefore, the CPU 40 stops.

[0051] At time t10, the auxiliary battery 11 is reinstalled. Here, the removal and reinstallation of the auxiliary battery 11 is not limited to the removal and installation accompanying the replacement of the auxiliary battery 11; it can also be a reinstallation of the same auxiliary battery only after temporarily disconnecting the cable. Figure 8 In other system configuration examples shown, the battery cut-off switch 12, located midway through the path, can be turned on after being temporarily disconnected.

[0052] By reinstalling the auxiliary battery 11, the connection between the auxiliary battery 11 and the auxiliary battery terminal 13 is switched from the disconnected state to the connected state. However, since the IG switch 22 remains open, under normal circumstances, the IG voltage is not supplied to the IG terminal 23, and the wake-up switch 32 is not turned on. Therefore, the VS voltage is not supplied to the control voltage generation unit 39.

[0053] However, if the wake-up switch 32 experiences a fixed connection failure, voltage is supplied to the control voltage generation unit 39 through the first power supply path P1, and the CPU 40 starts up. After startup, the CPU 40 performs initial checks sequentially. At time t11 during the initial checks, the CPU 40 performs the open / close determination of the IG switch 22, i.e., the LO determination of the IG voltage.

[0054] Thus, when the connection between the auxiliary battery 11 and the auxiliary battery terminal 13 switches from the disconnected state to the connected state, and the CPU 40 starts up, the CPU 40 monitors the IG voltage and the VS voltage. Moreover, if the IG voltage is in the LO state (below the turn-on threshold) but the VS voltage is in the HI state (above the determination threshold), the CPU 40 determines that the wake-up switch 32 has caused a fixed turn-on fault.

[0055] In addition to the possibility of a faulty connection in the actual wake-up switch 32 contacts, a detection state of "IG voltage is LO and VS voltage is HI" may also occur. For example, there may be a situation where the HI setting of the IG voltage determination circuit 33 is fixed, and although the actual IG voltage is less than the turn-on threshold, the IG voltage determination circuit 33 mistakenly determines that "IG voltage is above the turn-on threshold". In this case, the wake-up switch 32 is turned on according to the instruction of the IG voltage determination circuit 33, and the VS voltage is supplied. On the other hand, the monitoring value of the IG voltage monitoring circuit 53 is in the LO state, so the CPU 40 determines that there is a fault.

[0056] Therefore, in this embodiment, it is broadly interpreted as including cases where the "wake-up switch 32 on-time fixed fault" includes a HI fixed fault in the IG voltage determination circuit 33. In other words, the CPU 40, through the fault detection method described above, is not limited to detecting contact welding faults of the wake-up switch 32, but detects "wake-up switch 32 on-time fixed faults" including HI fixed faults in the IG voltage determination circuit 33. Furthermore, when the power relay 65 is on-time fixed, it also becomes a detection state of "IG voltage is LO and VS voltage is HI," but since the on-time fixed fault of the power relay 65 is detected before the initial check, it is not assumed in reality.

[0057] exist Figure 6 The flowchart shows the connection with Figure 3 The basic flow of the corresponding fault detection method is as follows. In the flowchart, "S" indicates a step. In S1, disconnect the IG switch 22 from normal control. In S2, remove the auxiliary battery 11. In S3, reinstall the auxiliary battery 11.

[0058] In the initial check (S4), CPU40 determines whether the IG voltage is less than the on-threshold. If the IG voltage is above the on-threshold but not in S4, the premise of this fault detection method is not met, so the process ends. In this case, for example, the process could proceed to determine whether there is a fixed on-threshold fault in IG switch 22 or a fault in IG voltage monitoring circuit 53.

[0059] If the IG voltage is below the turn-on threshold and S4 is true, proceed to S5. In S5, CPU40 determines whether the VS voltage is above the threshold or whether CPU40 is currently operating. If S5 is true, in S6, CPU40 determines that the wake-up switch 32 is in a fixed fault. Additionally, in S7, as a fault response measure, CPU40, for example, enters a sleep state. On the other hand, if S5 is false, in S8, CPU40 determines that it is functioning normally.

[0060] In this embodiment, even if the wake-up switch 32 experiences a fixed connection failure before the system stops, fault information is not stored. The CPU 40 detects faults by monitoring the actual voltage and its own operating state at the current moment. Since fault determination is not based on stored content, false determinations caused by changes in stored content can be prevented. Furthermore, when the CPU 40 is reset as a fault determination measure, repeated reset actions caused by false determinations can be prevented, thus preventing damage to the CPU 40 caused by exceeding the memory write limit.

[0061] (Modified Example)

[0062] A variation of the fault detection method described above will be explained. The logic of the fault detection method is to determine a fixed fault in the wake-up switch 32 when the IG voltage is LO (i.e., less than the turn-on threshold) and the VS voltage is HI (i.e., above the determination threshold). The timing of executing this determination logic is not limited to the startup of the CPU 40 immediately after the removal or installation of the auxiliary battery 11; it can be executed continuously. In other words, the CPU 40 can continuously monitor the IG voltage and VS voltage. Furthermore, if the IG voltage drops to the LO state due to some significant factor while the VS voltage remains at the HI state, a fixed fault in the wake-up switch 32 is determined.

[0063] Furthermore, the condition of VS voltage being HI is essentially synonymous with the condition that CPU40 is operating. Therefore, CPU40 can also replace the condition of "VS voltage being HI" with the condition of "CPU40 is operating". In other words, CPU40 can also determine that the wake-up switch 32 is in a fixed fault even if the CPU is operating despite the IG voltage being less than the turn-on threshold.

[0064] (Other system configuration examples)

[0065] (a) in Figure 7 , Figure 8 The diagram shows the fault detection method applied in this embodiment and its application to the fault detection method. Figure 1 Examples of different system configurations. In Figure 7In the system configuration example shown, the auxiliary battery 11 and the IG battery 21 are not independently provided; instead, the IG switch 22 is connected to the auxiliary battery 11. In other words, the auxiliary battery 11, serving as a "normal power source," also functions as the IG battery, which serves as a "starting power source." The same fault detection method can also be implemented in this configuration.

[0066] (b) in Figure 8 In the system configuration example shown, a battery cut-off switch 12 is provided midway through the path connecting the auxiliary battery 11 and the auxiliary battery terminal 13. The battery cut-off switch 12 is operated either by a control circuit different from that of the CPU 40 or manually by an operator. Figure 6 In S2 and S3, instead of removing and installing the auxiliary battery 11, the battery disconnect switch 12 is turned on after being temporarily disconnected. This makes fault detection easier.

[0067] (c) The “main power supply” and “starting power supply” are not limited to batteries, and can also be composed of capacitors or fuel cells. Alternatively, power that has been rectified from the output of the AC power supply can be input to the auxiliary battery terminal 13 and the IG terminal 23 instead of DC power.

[0068] (d) In contrast to the IG switch 22 in a motor vehicle, in hybrid and electric vehicles, the ready switch is equivalent to a "starting switch that is activated when the vehicle is started." Furthermore, not limited to driver button or push-button operations, in autonomous vehicles, start commands based on the control circuit are interpreted as "activation operations."

[0069] (e) "Electronic control device" is not limited to a device that drives an auxiliary motor of an electric power steering system, but can be a device that is activated by a CPU and performs various controls by a voltage supply from a power source provided by the vehicle.

[0070] This disclosure is not limited to such implementations and can be implemented in various ways without departing from its spirit.

[0071] The methods described herein may also be implemented by a special-purpose computer consisting of a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the methods described herein may be implemented by a special-purpose computer consisting of a processor composed of one or more special-purpose hardware logic circuits. Alternatively, the methods described herein may be implemented by one or more special-purpose computers consisting of a combination of a processor and memory programmed to perform one or more functions and a processor composed of one or more hardware logic circuits. Furthermore, computer programs may also be stored as instructions executable by a computer on a non-transferable tangible recording medium readable by a computer.

[0072] This disclosure is based on embodiments. However, this disclosure is not limited to these embodiments and structures. This disclosure also includes various modifications and variations within the same scope. In addition, various combinations and methods, and even other combinations and methods containing only one element, more or fewer elements, are also included in the scope and concept of this disclosure.

Claims

1. A fault detection method for detecting a fixed fault in the activation of a wake-up switch in an electronic control device. The aforementioned electronic control device includes: Common power terminals are connected to the common power supply installed in the vehicle; The starting power terminal is connected to the starting power supply via a starter switch that is activated when the vehicle is started. The CPU is started by supplying a common voltage, which is the voltage of the common power supply input through the common power supply terminal. as well as The wake-up circuit includes a wake-up switch that opens and closes the power supply path from the aforementioned common power supply terminal to the aforementioned CPU, and activates the wake-up switch when the voltage input to the aforementioned startup power supply terminal, i.e., the startup voltage, is above a threshold value. If the startup voltage is lower than the activation threshold but the normal operating voltage is higher than the determination threshold, the CPU determines that the wake-up switch has a fixed activation fault. The aforementioned wake-up switch is located inside the aforementioned electronic control device and is configured in the power supply path between the aforementioned common power supply terminal and the aforementioned CPU.

2. The fault detection method according to claim 1, wherein, When the connection between the aforementioned power supply and the aforementioned power supply terminal switches from a disconnected state to a connected state and the aforementioned CPU starts up, the aforementioned CPU performs fault determination.

3. A fault detection method for detecting a fixed fault in the activation of a wake-up switch in an electronic control device. The aforementioned electronic control device includes: Common power terminals are connected to the common power supply installed in the vehicle; The starting power terminal is connected to the starting power supply via a starter switch that is activated when the vehicle is started. The CPU is started by supplying a common voltage, which is the voltage of the common power supply input through the common power supply terminal. as well as The wake-up circuit includes a wake-up switch that opens and closes the power supply path from the aforementioned common power supply terminal to the aforementioned CPU, and activates the wake-up switch when the voltage input to the aforementioned startup power supply terminal, i.e., the startup voltage, is above a threshold value. If the CPU is operating even though the startup voltage is lower than the activation threshold, the CPU determines that the wake-up switch is in a fixed activation fault. The aforementioned wake-up switch is located inside the aforementioned electronic control device and is configured in the power supply path between the aforementioned common power supply terminal and the aforementioned CPU.

4. The fault detection method according to claim 1 or 3, wherein, The aforementioned wake-up circuit is located within the IC.

5. The fault detection method according to claim 1 or 3, wherein, The aforementioned wake-up circuit includes the aforementioned wake-up switch and determination circuit. When the start switch is turned on, the determination circuit determines whether the start-up voltage is above the turn-on threshold. The aforementioned wake-up switch and the aforementioned determination circuit are located within the IC.

6. An electronic control device, comprising: Common power terminals are connected to the common power supply installed in the vehicle; The starting power terminal is connected to the starting power supply via a starter switch that is activated when the vehicle is started. The CPU is started by supplying a common voltage, which is the voltage of the common power supply input through the common power supply terminal. as well as The wake-up circuit has a wake-up switch that turns the power supply path from the aforementioned common power supply terminal to the aforementioned CPU on and off, and turns on the wake-up switch when the voltage input to the aforementioned startup power supply terminal, i.e., the startup voltage, is above a threshold value. If the starting voltage is less than the activation threshold but the normal operating voltage is above the determination threshold, or if the CPU is operating even though the starting voltage is less than the activation threshold, the CPU determines that the wake-up switch is in a fixed activation fault. The aforementioned wake-up switch is located inside the aforementioned electronic control device and is configured in the power supply path between the aforementioned common power supply terminal and the aforementioned CPU.

7. The electronic control device according to claim 6, wherein, The aforementioned wake-up circuit is located within the IC.

8. The electronic control device according to claim 6, wherein, The aforementioned wake-up circuit includes the aforementioned wake-up switch and determination circuit. When the start switch is turned on, the determination circuit determines whether the start-up voltage is above the turn-on threshold. The aforementioned wake-up switch and the aforementioned determination circuit are located within the IC.

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