(19)
(11)EP 2 020 497 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
26.06.2019 Bulletin 2019/26

(21)Application number: 08013848.0

(22)Date of filing:  01.08.2008
(51)International Patent Classification (IPC): 
F02D 41/22(2006.01)
B60W 50/04(2006.01)
G07C 5/08(2006.01)
F02D 41/24(2006.01)
G07C 3/00(2006.01)

(54)

Electronic control unit

Elektronische Steuereinheit

Unité de commande électrique


(84)Designated Contracting States:
DE FR

(30)Priority: 03.08.2007 JP 2007203110

(43)Date of publication of application:
04.02.2009 Bulletin 2009/06

(73)Proprietor: Denso Corporation
Kariya-shi, Aichi-pref 448-8661 (JP)

(72)Inventor:
  • Teramura, Mikio
    Kariya-city Aichi-pref., 448-8661 (JP)

(74)Representative: Winter, Brandl, Fürniss, Hübner, Röss, Kaiser, Polte - Partnerschaft mbB 
Patent- und Rechtsanwaltskanzlei Alois-Steinecker-Strasse 22
85354 Freising
85354 Freising (DE)


(56)References cited: : 
WO-A1-96/26486
US-A1- 2003 146 754
US-A- 5 964 813
US-B1- 6 601 015
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description


    [0001] The present disclosure generally relates to an electronic control unit for storing abnormality information as a result of diagnosis in a rewritable non-volatile memory.

    [0002] The electronic control unit stores, as a result of diagnosis, abnormality information, e.g., Diagnostic Trouble Code (DTC), of various diagnosis objects in a rewritable non-volatile memory such as an EEPROM or the like based on information from various sensors installed in the vehicle indicating faulty operation of the diagnosis object.

    [0003] The electronic control unit having the above-mentioned function may be operated, for example, during a manufacturing process of the vehicle. In such a case, the electronic control unit is operated in a condition that the assembly of the electronic control unit has not yet been complete, that is, in a condition that the apparatus is being operable in the vehicle without the connection of connectors to peripheral devices such as relevant sensors, electronic loads and the like.

    [0004] Thus, if the electronic control unit is operated to perform diagnosis of peripheral devices, the abnormality is detected by the apparatus, thereby leading to storage of useless abnormality information in the rewritable non-volatile memory.

    [0005] Therefore, the electronic control unit disclosed in, for example, Japanese patent document JP-A-2006-291730, has a configuration for avoiding storage of the useless abnormality information. That is, the apparatus determines whether or not the vehicle is being used by a user based on a driving condition of the vehicle such as a vehicle speed, an engine rotation or the like, and starts storage of a diagnosis result to a storage unit after determining that the use of the vehicle by the user has been started.

    [0006] However, the above disclosure uses, as a criterion for starting storage of the diagnosis result, a driving condition that can be assumed as a use of the vehicle by a user and cannot be assumed to be happening in the manufacturing process of the vehicle. Thus, the start of the storage of the diagnosis result may be delayed by a certain period from an actual start of the use of the vehicle by the user.

    [0007] Therefore, the abnormality information regarding abnormality that has happened relatively immediately after the start of the use of the vehicle by the user, that is, the abnormality information that should be stored, may be prevented from being stored in the rewritable non-volatile memory.

    [0008] Document US 2003/0146754 A1 describes a data holding device including a switch adapted to be turned on and off in accordance with a state of an engine, a control element in the form of a CPU for determining the presence or absence of abnormality in the engine based on a state of the switch, a data storage element in the form of an EEPROM for storing recognized data corresponding to the presence or absence of abnormality, an external power supply for supplying a power supply voltage to the CPU, and a voltage holding circuit for holding the power supply voltage at a prescribed value. When abnormality is found in the engine, plural pieces of recognized data indicative of abnormality are stored in the EEPROM, and the engine state is determined based on groups of recognized data stored in the EEPROM.

    [0009] In view of the above and other problems, an aspect of the present disclosure provides an electronic control unit configured to exclusively prevent storage of useless abnormality information detected by the apparatus in a rewritable non-volatile memory from among all of the detected abnormality information during a manufacturing process of the vehicle for installing the apparatus in the vehicle.

    [0010] The present invention is defined by the features of claim 1. The dependent claims are directed to preferred embodiments of the invention.

    [0011] The invention relates to an electronic control unit configured to be installed in a vehicle as set forth in claim 1. The electronic control unit configured to be installed in a vehicle includes: a non-volatile memory capable of re-writing data stored therein; and a diagnosis unit capable of checking if failure occurs in a device installed in the vehicle based on information therefrom and of storing abnormality data in the non-volatile memory after determining abnormality has occurred in the device installed in the vehicle.

    [0012] The apparatus further includes: a permission information storage capable of storing permission information indicating whether or not storage of the abnormality information in the non-volatile memory is permitted; and a permission switching unit capable of switching the permission information from non-permission of the storage of the abnormality information to permission of the storage of the abnormality information when the normal condition of the device based on the diagnosis of the diagnosis unit after completion of the installation of the electronic control unit in the vehicle is detected.

    [0013] Furthermore, the apparatus includes a storage unit capable of permitting the diagnosis unit to store the abnormality information in the non-volatile memory when the permission information stored in the permission information storage indicates permission of the storage of the abnormality information in the non-volatile memory.

    [0014] The above-mentioned electronic control unit does not store the abnormality information in the rewritable non-volatile memory even when an assembly of the apparatus being in a non-completion condition yields diagnosis indicating abnormality during its operation in a vehicle manufacturing process, because the permission information in the permission information storage still indicates non-permission of the storage of the abnormality information. In this case, the completion of the assembly of the electronic control unit means that the all of the relevant devices in the vehicle intended to be connected to the apparatus such as sensors, electronic loads or the like are orderly connected to the apparatus.

    [0015] When the normal condition of the device based on the diagnosis of the diagnosis unit after completion of the installation of the apparatus in the vehicle is detected by the permission switching unit, the permission information is switched from indicating the non-permission of the storage to indicating the permission of the storage.

    [0016] At the point of detecting the normal condition, the storage permission unit permits the storage of the abnormality information in the rewritable non-volatile memory. Therefore, the abnormality detected based on the diagnosis by the diagnosis unit is stored in the rewritable non-volatile memory.

    [0017] The electronic control unit being operated in the above operation scheme prevents useless abnormality information detected during the installation process of the apparatus from being stored in the rewritable non-volatile memory, and permits the abnormality information detected after the completion of installation of the apparatus in the vehicle to be stored in the rewritable non-volatile memory. That is, in other words, the useless abnormality information that is detected during the manufacturing process of the vehicle is exclusively prevented from being stored in the rewritable non-volatile memory.

    [0018] Regarding vehicle diagnosis, the regulation of California Air Resources Board (CARB) requires that DTC that has been stored as the diagnosis results is stored in a rewritable non-volatile memory such as EEPROM of an electronic control unit as a permanent fault code (Permanent Diagnostic Trouble Code, or PDTC), and the PDTC must not be erasable by a command from an external tool that is capable of communicating with the electronic control unit. However, the above-mentioned electronic control unit is readily compliant to the above requirement, because the useless information to be erased is prevented from being stored in the rewritable non-volatile memory.

    [0019] In addition, if the diagnosis unit is configured to determine not only whether or not the diagnosis object is abnormal but also whether or not the diagnosis object is normal, the permission switching unit may refer to the diagnosis result of the diagnosis unit regarding the diagnosis object. That is, in other words, the permission switching unit may be configured to determine that the diagnosis object is normal when the diagnosis unit determines that the diagnosis object is normal.

    [0020] Further, the diagnosis object may be only one device, or may be plural devices. In this case, if the diagnosis unit performs diagnosis for plural diagnosis objects, the permission switching unit may determine that the diagnosis result is normal when the diagnosis by the diagnosis unit regarding all of the diagnosis objects is not abnormal.

    [0021] Furthermore, the above advantageous effects are achieved by devising that the data in the non-volatile memory is changed from an initial value to a different value, as an indicator of permission of the storage of the DTC, at a time after completion of the installation of the electronic control unit in the vehicle and before shipment of the vehicle from the factory.

    [0022] Other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings, in which:

    FIG. 1 is a configuration diagram showing an ECU (an electronic control unit) in an embodiment of the present invention;

    FIG. 2 is a flowchart showing an abnormal information memory processing in the embodiment of the present invention;

    FIG. 3 is a flowchart showing a permission switching process in the embodiment of the present invention;

    FIG. 4 is a flowchart showing an EEPROM data reply processing in the embodiment of the present invention; and

    FIG. 5 is a flowchart showing a procedure of the installation confirmation work in the embodiment of the present invention.



    [0023] An embodiment of the present invention is explained in the following. First, FIG. 1 is a configuration showing an electronic control unit (ECU) 1 of the present embodiment. In addition, the ECU 1 of the present embodiment is installed in a vehicle, and the engine of the vehicle is controlled thereby.

    [0024] As for the ECU 1, a CPU (a central processing unit) 3, a ROM 5 to store a program executed by the CPU 3, data referred to in the execution of the program and other data such as diagnosis trouble codes necessary for the ECU 1 for example, a RAM 7 for temporarily store the data, a standby RAM (SRAM) 9 continuously having supply of data retaining electric power, an EEPROM 11 made of rewritable non-volatile memory, an the input circuit 13, and an output circuit 15 as shown in FIG. 1 are included therein.

    [0025] Various signals such as an output Pb of an inlet pipe pressure sensor, an output Ne of an engine rotation sensor, an output Tw of an engine water temperature sensor, an output O2 of an oxygen sensor (an air-fuel ratio sensor) in an exhaust system, an output V of a vehicle speed sensor, an output IGN of an ignition switch are input into the CPU 3 through the input circuit 13 as information for controlling an engine. In addition, the output circuit 15 outputs a drive signal to electric loads such as an ignition, an injector and a warning lamp (e.g., MIL: Mulfunction Indicator Lamp) according an instruction from the CPU 3.

    [0026] The CPU 3 executes calculation for engine control based on various signals that are input to the CPU 3 through the input circuit 13, and supplies instructions to the output circuit 15 based on the calculation results, to thereby control the electric loads related to the control of the engine. For example, the CPU 3 calculates a valve opening timing and a valve opening period of fuel injectors, and supplies an instrucion for driving the injectors to the output circuit 15 based on the calculation results, to thereby control fuel injection into the engine.

    [0027] In addition, in the ECU 1, a communication circuit 17 for the CPU 3 to communicate with other devices such as a navigation apparatus connected to a communication line 21 in the vehicle or the like is included. Furthermore, an external tool 23 to perform a fault diagnosis of the vehicle or the like connectable to the communication line 21 through a connector which is not illustrated is provided. The external tool 23 is a small personal computer or a device of handy type including a display unit and a microcomputer.

    [0028] The power supplies to the ECU 1 include an operation power supply that is supplied from an in-vehicle battery (not shown) in association with the on/off operation of the ignition switch, and a backup power supply that is continuously supplied to the standby RAM 9 from the in-vehicle battery even when the ignition switch is held turned off. The ECU 1 operates upon receiving the operation power supply when the ignition switch is turned on. Also, a constant voltage that is generated from the backup power supply by a power supply circuit (not shown) within the ECU 1 is continuously supplied to the standby RAM 9 as the data retention power supply.

    [0029] The process that the CPU 3 in the ECU 1 carries out is explained in the following. For example, the CPU 3 of the ECU 1 executes, in parallel with processing to control the engine, each of the processes in FIG. 2 - FIG. 4 at every predetermined time.

    [0030] First, FIG. 2 is a flowchart showing an abnormal information memory processing. A diagnosis process to detect abnormality in S110 is performed when the CPU 3 starts the execution of the abnormal information memory processing. The processing is to determine whether a device or a section pertaining to a signal is abnormal based on signals from various sensors, switches or the like input through the input circuit 13. The diagnosis is performed for plural diagnosis objects (e.g., diagnosis items).

    [0031] For example, as the diagnosing process for detecting the abnormality of a certain sensor, the CPU 3 checks whether the output value of the sensor is normal, that is, within a predetermined range or not. If a condition that the output value falls within the predetermined range is kept for a predetermined period, the CPU 3 determines that the sensor is normal. If a condition that the output value does not fall within the predetermined range is kept for a predetermined period, the CPU 3 determines that the sensor is abnormal. In addition, an abnormality detection range for determining the abnormality may be, for some processes, set as a different range as a predetermined range for determining that a device is normal.

    [0032] Then, in S120, the CPU 3 checks whether there is any abnormality detection item, that is, a diagnosis object, which has been determined as abnormal in the above diagnosing process. If there is no object that has been determined as abnormal, the CPU 3 ends the abnormal information memory processing.

    [0033] If there is any diagnosis object that has been determined as abnormal (Yes in S120), the CPU 3 proceeds to S130, and stores a diagnostic trouble code (DTC, that is, diagnosis result indicating that the diagnosis object is abnormal) corresponding to the object which has been determined as abnormal in the standby RAM 9. When a predetermined condition is met, for example, when the same abnormality is detected continuously for two trips, the malfunction indicating light is turned on. Each trip may be defined as a period between on-operation and off-operation of the ignition switch.

    [0034] Then, the process determines whether storage of the DTC to the EEPROM 11 is allowed in S140 next. More practically, the data in the EEPROM 11 is all initialized to zero at the time of the production of the ECU 1. Then, as the EEPROM 11 of the present embodiment is used to store data of 16 bits for each address, data in each address of the EEPROM 11 is set to "$ 0000" at the time of production of the ECU 1. In this case, the character string starting with '$' sign means that the character string represents a number of hexadecimal notation.

    [0035] In addition, in the present embodiment, a storage area corresponding to a predetermined address range from a top of the memory address may be, for example, set as a DTC storage for storing the DTC (e.g., the abnormality information memory area, designated as a DTC storage in the following description).

    [0036] Then, in S140, whether the data of the top address of the DTC storage is "$ 0000," that is, the initial value is determined. If the data is "$ 0000", the process determines that DTC storage to the EEPROM 11 is not allowed, and if the data is not "$ 0000," the process determines that DTC storage to the EEPROM 11 is allowed.

    [0037] When it is determined that DTC storage to the EEPROM 11 is not allowed in this S140, the abnormality information memory processing is simply finished. When it is determined DTC storage to the EEPROM 11 is allowed, the process proceeds to S150.

    [0038] Then, in S150, DTC corresponding to the diagnosis object determined to be abnormal by the diagnosis process (DTC which is memorized to the standby RAM in S130) is memorized as a PDTC in the DTC storage of the EEPROM 11. Then, the abnormality information memory processing is finished.

    [0039] In addition, in S150, DTC is to be memorized sequentially from the top address of the DTC storage. In other words, in the DTC storage, DTC showing abnormality detected earlier is memorized in an address of closer to a top address.

    [0040] FIG. 3 is a flowchart showing a permission switching process to change DTC storage to the EEPROM 11 from non-permission state to permission state. When the CPU 3 of the ECU 1 starts execution of the permission switching process, first, in S210, the data of the top address of the DTC storage area in the EEPROM 11 is determined whether it is "$ 0000" that is identical with the initial value, and the permission switching process is simply finished if the data is not "$ 0000" (i.e., if some data is overwritten on the initial value). If the data is "$ 0000," the process proceeds to S220.

    [0041] In S220, whether all diagnosis objects diagnosed by the diagnosis process (S110 of FIG. 2) that is mentioned above are determined to be normal with no indication of abnormality by the diagnosis process. More practically, whether the diagnosis process has determined that all of the diagnosis objects are normal is determined.

    [0042] In this case, if some of the diagnosis objects have a relation that a normal condition of a diagnosis object D1 detected by the diagnosis process never leads to an abnormal condition of a diagnosis object D2 by the diagnosis process, determination process for the diagnosis object D2 can be omitted in S220. On the other hand, if there is a certain diagnosis object which is not determined whether or not it is in a normal condition by the diagnosis process, that is, an object which is only determined whether or not it is in an abnormal condition, the diagnosis object of that kind may be determined whether or not it is in a normal condition by performing the diagnosis process anew in S220 (e.g., the diagnosis process for determining whether or not the censor output value is in a normal range).

    [0043] When all diagnosis objects are not determined to be in a normal condition in S220, the permission switching process concerned is simply finished. However, when all diagnosis objects are determined to be in a normal condition (i.e., when the diagnosis process does not detects a condition of abnormality), the process proceeds to S230.

    [0044] In S230, the process writes, to the top address of the DTC storage area in the EEPROM 11, a code indicating "normal" (e.g., a code "$ 5AA5" in the present embodiment) and different from any of the DTC, and then the permission switching process is finished. When, in S230, the data at the top address of the DTC storage area is rewritten from "$ 0000" to "$ 5AA5," the storage of the DTC to the EEPROM 11 is determined to be allowed thereafter in S140 of FIG. 2 as mentioned before.

    [0045] In addition, in S230, "$ 5AA5" may be written in at all addresses of the DTC storage in the EEPROM 11. Further, in S140 of FIG. 2, whether all data of the DTC storage in the EEPROM 11 are having the initial value ($ 0000) may be determined. If it is determined that all data is having the initial value, storage of the DTC to the EEPROM 11 is determined to be not allowed, or if it is determined that all data is not having the initial value, storage of the DTC to the EEPROM 11 is determined to be allowed. The same determination scheme is applicable to S320 in FIG. 4 that is mentioned later.

    [0046] FIG. 4 is a flowchart showing a EEPROM data reply processing for returning data in data of the DTC storage in the EEPROM 11 in response to a request from the external tool 23. When the process is started by the CPU 3 of the ECU 1, whether a "MODE-OA" command requesting the data of the DTC storage area in the EEPROM 11 from among request command signals transmitted from the external tool 23 is received or not is determined in S310.

    [0047] Subsequently, if the "MODE-OA" command is not received (S310:NO), the EEPROM data reply processing is simply finished. If the "MODE-OA" command is received (S310:YES), the process proceeds to S320, and performs the same processing as S140 of FIG. 2. In other words, it determines whether storage of the DTC to the EEPROM 11 is allowed or not.

    [0048] When it is determined that storage of the DTC to the EEPROM 11 is not allowed in S320, the EEPROM data reply processing is simply finished. When it is determined that storage of the DTC to the EEPROM 11 is allowed, the process proceeds to S330.

    [0049] Then, in S330, the data of the DTC storage in the EEPROM 11 is transmitted to the external tool 23, and then the EEPROM data reply processing concerned is finished. In addition, though the flowchart is omitted, the data of the memory area that is set to memorize the DTC in the standby RAM 9 is configured to be transmitted to the external tool 23 when the CPU 3 of the ECU 1 receives a command to request the DTC in the standby RAM 9 from among commands transmitted from the external tool 23.

    [0050] According to the ECU 1 configured to operate in the above-described manner, if the ECU 1 concerned starts operation in a state that installation of the ECU 1 to the vehicle is not completed during the production process of the vehicle, and the diagnosis process (S110 of FIG. 2) determines abnormality of at least one of the diagnosis objects, the DTC is not stored to the EEPROM 11 due to the data in the EEPROM 11 being maintained as the initial value at that point and due to the determination that the data indicates that the storage of the DTC to the EEPROM 11 is not allowed.

    [0051] Then, upon completion of the installation of the ECU to the vehicle that leads to a normal condition of the diagnosis object diagnosed by the diagnosis process as not being abnormal and also leads to a determination in S220 in FIG. 3, the data of the top address of the DTC area in the EEPROM 11 is rewritten from "$ 0000" of the initial value to "$ 5AA5" in S230.

    [0052] Then, starting at the time when the data is rewritten, storage of the DTC to the EEPROM 11 is determined to be allowed in S140 of FIG. 2 and in S320 of FIG. 4. Therefore, the DTC to indicates the abnormality is memorized in the DTC area of the EEPROM 11 thereafter when it is determined that at least one of the diagnosis object is determined to be abnormal by the diagnosis process.

    [0053] Thus, according to the ECU 1 of the present embodiment, the DTC showing abnormality detected in vain during the installation to the vehicle to (in other words, during a production time of the vehicle) is configured to be prevented from being stored in the EEPROM 11, and the DTC showing abnormality detected after the installation to the vehicle (in other words, after completion of the vehicle) is configured to be permitted to be stored in the EEPROM 11. Therefore, from among the diagnostic trouble codes (DTC's), useless DTC's detected during the production time of the vehicle for indicating abnormality are exclusively prevented from being stored in the EEPROM 11. Further, a similar advantageous effect is achieved when the ECU 1 concerned is changed for a new one in a vehicle repair shop.

    [0054] Furthermore, according to the ECU 1 of the present embodiment, because permission information of whether or not to permit the storage od the DTC to the EEPROM 11 is configured to be stored to the EEPROM 11, the permission information is continuously maintained even when a vehicle battery is taken off from the vehicle, or even when the vehicle battery decreases or runs out. Therefore, returning to a non-permission (prohibition) condition regarding DTC storage to the EEPROM 11 after the vehicle is started to be used by a user is securely prevented.

    [0055] Furthermore, in the present embodiment in particular, the DTC storage area in the EEPROM 11 serves as both of the DTC storage and permission information storage. More practically, the data of the top address of the DTC storage area is used as the permission information, and the data being not equal to the initial value indicates that the storage of the DTC to the EEPROM 11 is permitted. Therefore, it is not necessary to establish a dedicated memory area for exclusively storing the permission information in the EEPROM 11, thereby leading to a reduction of the dedicated memory area in the EEPROM 11.

    [0056] In addition, it can be easily confirmed whether installation of the ECU 1 to the vehicle is completed normally by an installation confirmation operation as shown in FIG. 5 in the manufacturing facility of the vehicle because the EEPROM data reply processing of FIG. 4 performed.

    [0057] That is, the external tool 23 is connected to the communication line 21 after completion of the installation of the ECU 1 to the vehicle, and the external tool 23 is operated to transmit the above-mentioned "MODE-OA" command from the external tool 23 to the ECU 1 (S410). In addition, when an operation to transmit the "MODE-OA" command is performed, the external tool 23 is configured to transmits the "MODE-OA" command to the ECU 1, and also configured to display, on a display unit disposed on the external tool 23, the data which is transmitted from the ECU 1 in response to the command from the external tool 23.

    [0058] When, from the ECU 1 to the external tool 23, the response data corresponding to the "MODE-OA" command is transmitted, that is, when the data of the DTC storage area in the EEPROM 11 is transmitted (S420:YES), the transmission of the data indicates that all of the diagnosis objects of the diagnosis process in the ECU 1 are in a normal condition and that storage of the DTC to the EEPROM 11 is permitted, thereby leading to a determination that the installation of the ECU 1 to the vehicle is normal (S430).

    [0059] In addition, when the response data corresponding to the "MODE-OA" command is not transmitted from the ECU 1 to the external tool 23 (S420:NO), it can be determined that the diagnosis object of the diagnosis process in the ECU 1 is not in a normal condition, indicating that storage of the DTC to the EEPROM 11 is not permitted. Therefore, the installation of the ECU 1 to the vehicle is determined to be not in a normal condition (S440).

    [0060] Thus, in that case, the external tool 23 is operated to transmit a command to request the DTC in the standby RAM 9, and, by viewing the data displayed on the display unit of the external tool 23 after being transmitted from the ECU 1 to the external tool 23 in response to the command (i.e., the DTC in the standby RAM 9), the contents of the abnormality can easily be analyzed such as a failure of connection occurring at a certain point or the like (S450).

    [0061] In other words, because storage of the DTC to the standby RAM 9 is always permitted in the ECU 1 (S130), the DTC to show abnormality detected during installation of the ECU 1 to the vehicle remains in the standby RAM 9. Therefore, about a malfunction, a trouble and the like that occurred during the installation to the vehicle can be analyzed easily by retrieving the DTC in the standby RAM 9.

    [0062] Furthermore, according to the ECU 1 of the present embodiment, when the response data in response to the "MODE-OA" command from the external tool 23 has been sent back to the external tool 23 (S420:YES), it indicates that the data of the top address of the DTC storage in the EEPROM 11 is rewritten from "0000" to "& 5AA5," thereby leading to a confirmation that reading to and writing from the EEPROM 11 are performed normally on a basis that the process has performed the confirmation in S320 of FIG. 4. In addition, at the same time with such a confirmation, the data of the DTC storage in the EEPROM 11 can be confirmed, particularly on the point that the data at the top address of the DTC storage is rewritten from "$ 0000" to "& 5AA5."

    [0063] In addition, when a diagnosis for completion of the installation that all of the diagnosis objects are determined to be normal is provided after the installation of all of the diagnosis objects to the vehicle and before a shipment of the vehicle, rewriting of the data at the top address of the DTC storage in the EEPROM from "$ 0000" to "& 5AA5" indicates that storage of the PDTC to the EEPROM 11 is permitted, thereby leading to securely storing the DTC that must be diagnosed and stored for indicating abnormality at a stage that the vehicle is ready to be used in an actual condition after completion of inspection at the manufacturing plant.

    [0064] In addition, the confirmation process by using the external tool 23 as described above can be carried out in the same manner when the ECU 1 is replaced with a new one in a repair shop of the vehicle. On the other hand, in the present embodiment, S110 in FIG. 2 as well as S120, S130 and S150 are equivalent to a diagnosis unit, and determination processing of S140 is equivalent to a storage permission unit, and processing of FIG. 3 is equivalent to a permission switching unit. Further, the DTC storage area (a storage area at the top address thereof in particular) in the EEPROM 11 is equivalent to a permission information storage unit. Furthermore, the external tool 23 is equivalent to an external device, and processing of FIG. 4 is equivalent to response unit.

    [0065] Although the present invention has been fully described in connection with the preferred embodiment thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art.

    [0066] For example, the permission information to indicate whether storage of the DTC to the EEPROM 11 is allowed may be stored in an area other than the DTC storage area in the EEPROM 11, or it may be stored in the standby RAM 9.

    [0067] In addition, the rewritable nonvolatile memory may not only be, for example, the EEPROM, but also a flash memory.

    [0068] Such changes and modifications are to be understood as being within the scope of the present invention as defined by the appended claims.


    Claims

    1. An electronic control unit (1) configured to be installed in a vehicle, the electronic control unit (1) comprising:

    a non-volatile memory (11) capable of re-writing data stored therein;

    a diagnosis unit (3) capable of checking if failure occurs in a device installed in the vehicle based on information therefrom and storing abnormality data in the non-volatile memory after determining abnormality has occurred in the device installed in the vehicle;

    a permission information storage (11) capable of storing permission information indicating whether or not storage of the abnormality information in the non-volatile memory is permitted;

    a storage unit (3) capable of permitting the diagnosis unit to store the abnormality information in the non-volatile memory when the permission information stored in the permission information storage (11) indicates permission of the storage of the abnormality information in the non-volatile memory;

    a permission switching unit (3) capable of switching the permission information from non-permission of the storage of the abnormality information to permission of the storage when the normal condition of the device based on the diagnosis of the diagnosis unit after completion of the installation of the electronic control unit (1) in the vehicle is detected; the electronic control unit (1) being characterized by

    a standby RAM (9) to which electric power is continuously supplied for storing data,

    wherein

    the diagnosing unit (3) is configured to be continuously permitted to store the diagnosis result in the standby RAM, wherein the diagnosis result to show abnormality detected during installation of the electronic control unit (1) to the vehicle remains in the standby RAM (9).
     
    2. The electronic control unit (1) according to claim 1, wherein
    the permission information storage is a predetermined memory area in the non-volatile memory.
     
    3. The electronic control unit (1) according to claim 2, wherein
    the predetermined memory area is one of a part of the memory area for storing the abnormality data and a whole of the memory area for storing the abnormality data in the non-volatile memory,
    the permission switching unit re-writes data in the predetermined memory area from an initial value that is set prior to installation of the electronic control unit (1) in the vehicle to a specific value that is different from the abnormality data upon determining that the device installed in the vehicle is in the normal condition,
    data having the initial value in the predetermined memory area indicates non-permission of the storage of the abnormality information, and
    data not having the initial value in the predetermined memory area indicates permission of the storage of the abnormality information.
     
    4. The electronic control unit (1) according to any one of claims 1 to 3 further comprising:

    a response unit (17) configured to, when a request signal transmitted from an external device is received on a condition that the permission information indicates permission of the storage of the abnormality information, transmit a response signal in response to the request signal to the external device, wherein

    the request signal requests data in the memory area that is used to store the abnormality information in the non-volatile memory, and

    the response signal comprises data in the memory area that is used to store the abnormality information to the external device.


     
    5. An electronic control unit (1) of claim 1, comprising means for performing the diagnosis of the device installed in the vehicle prior to shipment of the vehicle.
     
    6. An electronic control unit (1) of claim 1, wherein
    the non-volatile memory has an initial value stored in all of memory areas in a pre-installation condition in the vehicle,
    the electronic control unit (1) comprising means for permitting storage of a result of diagnosis by the diagnosis unit in the non-volatile memory when change of the initial value is detected in a period after installation of the electronic control unit (1) in the vehicle and before shipment of the vehicle.
     


    Ansprüche

    1. Elektronische Steuereinheit (1), die so konfiguriert ist, dass sie in einem Fahrzeug installiert ist, wobei die elektronische Steuereinheit (1) aufweist:

    einen nichtflüchtigen Speicher (11), der imstande ist, Daten, die darin gespeichert sind, umzuschreiben,

    eine Diagnoseeinheit (3), die imstande ist, zu überprüfen, wenn ein Fehler in einer im Fahrzeug installierten Vorrichtung auftritt, auf Grundlage einer Information davon und Abnormalitätsdaten im nichtflüchtigen Speicher zu speichern, nachdem bestimmt wurde, dass eine Abnormalität in der im Fahrzeug installierten Vorrichtung aufgetreten ist,

    einen Erlaubnisinformationsspeicher (11), der imstande ist, eine Erlaubnisinformation zu speichern, die angibt, ob eine Speicherung der Abnormalitätsinformation im nichtflüchtigen Speicher erlaubt ist oder nicht,

    eine Speichereinheit (3), die imstande ist, dass sie es der Diagnoseeinheit erlaubt, die Abnormalitätsinformation im nichtflüchtigen Speicher zu speichern, wenn die im Erlaubnisinformationsspeicher (11) gespeicherte Erlaubnisinformation eine Erlaubnis der Speicherung der Abnormalitätsinformation im nichtflüchtigen Speicher angibt,

    eine Erlaubniswechseleinheit (3), die imstande ist, die Erlaubnisinformation von einer Nicht-Erlaubnis der Speicherung der Abnormalitätsinformation zu einer Erlaubnis der Speicherung zu wechseln, wenn der normale Zustand der Vorrichtung auf Grundlage der Diagnose der Diagnoseeinheit nach einem Abschluss der Installation der elektronischen Steuereinheit (1) in das Fahrzeug erfasst wird, wobei die elektronische Steuereinheit (1) gekennzeichnet ist durch:

    einen Standby-RAM (9), dem elektrische Energie zum Speichern von Daten kontinuierlich zugeführt wird,

    wobei

    die Diagnoseeinheit (3) so konfiguriert ist, dass es ihr kontinuierlich erlaubt ist, das Diagnoseergebnis im Standby-RAM zu speichern, wobei das Diagnoseergebnis zum Zeigen einer Abnormalität, die während der Installation der elektronischen Steuereinheit (1) in das Fahrzeug erfasst wird, im Standby-RAM (9) verbleibt.


     
    2. Elektronische Steuereinheit (1) nach Anspruch 1, wobei
    der Erlaubnisinformationsspeicher ein vorgegebenes Speichergebiet im nichtflüchtigen Speicher ist.
     
    3. Elektronische Steuereinheit (1) nach Anspruch 2, wobei
    das vorgegebene Speichergebiet eines von einem Teil des Speichergebiets zum Speichern der Abnormalitätsdaten und ein Ganzes des Speichergebiets zum Speichern der Abnormalitätsdaten im nichtflüchtigen Speicher ist,
    die Erlaubniswechseleinheit Daten im vorgegebenen Speichergebiet von einem Initialwert, der vor einer Installation der elektronischen Steuereinheit (1) in das Fahrzeug festgelegt wird, auf einen spezifischen Wert, der von den Abnormalitätsdaten verschieden ist, umschreibt, nachdem bestimmt wurde, dass die im Fahrzeug installierte Vorrichtung im normalen Zustand ist,
    Daten, die den Initialwert aufweisen, im vorgegebenen Speichergebiet eine Nicht-Erlaubnis der Speicherung der Abnormalitätsinformation angeben, und
    Daten, die den Initialwert nicht aufweisen, im vorgegebenen Speichergebiet eine Erlaubnis der Speicherung der Abnormalitätsinformation angeben.
     
    4. Elektronische Steuereinheit (1) nach einem der Ansprüche 1 bis 3, die ferner aufweist:

    eine Antworteinheit (17), die so konfiguriert ist, dass sie, wenn ein von einer externen Vorrichtung übertragenes Anfragesignal in einem Zustand empfangen wird, in dem die Erlaubnisinformation eine Erlaubnis der Speicherung der Abnormalitätsinformation angibt, ein Antwortsignal als Antwort auf das Anfragesignal zur externen Vorrichtung überträgt, wobei

    das Anfragesignal Daten im Speichergebiet anfragt, das verwendet wird, um die Abnormalitätsinformation im nichtflüchtigen Speicher zu speichern, und

    das Antwortsignal Daten im Speichergebiet aufweist, das verwendet wird, um die Abnormalitätsinformation zur externen Vorrichtung zu speichern.


     
    5. Elektronische Steuereinheit (1) nach Anspruch 1, die ein Mittel zum Durchführen der Diagnose der im Fahrzeug installierten Vorrichtung vor einer Lieferung des Fahrzeugs aufweist.
     
    6. Elektronische Steuereinheit (1) nach Anspruch 1, wobei
    der nichtflüchtige Speicher einen Initialwert, der in allen Speichergebieten gespeichert ist, in einem Zustand vor der Installation in das Fahrzeug aufweist,
    die elektronische Steuereinheit (1) ein Mittel zum Erlauben einer Speicherung eines Ergebnisses einer Diagnose durch die Diagnoseeinheit im nichtflüchtigen Speicher, wenn eine Änderung des Initialwerts in einem Zeitraum nach einer Installation der elektronischen Steuereinheit (1) in das Fahrzeug und vor einer Lieferung des Fahrzeugs erfasst wird, aufweist.
     


    Revendications

    1. Unité de commande électronique (1) configurée pour être installée dans un véhicule, l'unité de commande électronique (1) comprenant :

    une mémoire non volatile (11) capable de réécrire des données stockées dans celle-ci ;

    une unité de diagnostic (3) capable de vérifier si une défaillance survient dans un dispositif installé dans le véhicule à partir d'informations provenant de celui-ci et de stocker des données d'anomalie dans la mémoire non volatile après avoir déterminé qu'une anomalie est survenue dans le dispositif installé dans le véhicule ;

    un stockage d'informations d'autorisation (11) capable de stocker des informations d'autorisation indiquant si le stockage des informations d'anomalie dans la mémoire non volatile est autorisé ou non ;

    une unité de stockage (3) capable d'autoriser l'unité de diagnostic à stocker les informations d'anomalie dans la mémoire non volatile lorsque les informations d'autorisation stockées dans le stockage d'informations d'autorisation (11) indiquent une autorisation du stockage des informations d'anomalie dans la mémoire non volatile ;

    une unité de commutation d'autorisation (3) capable de commuter les informations d'autorisation de la non-autorisation du stockage des informations d'anomalie jusqu'à l'autorisation du stockage lorsque l'état normal du dispositif basé sur le diagnostic de l'unité de diagnostic après l'achèvement de l'installation de l'unité de commande électronique (1) dans le véhicule est détecté ; l'unité de commande électronique (1) étant caractérisée par

    une RAM de secours (9) à laquelle de l'énergie électrique est fournie en continu pour stocker des données,

    dans laquelle

    l'unité de diagnostic (3) est configurée pour être autorisée en continu à stocker le résultat de diagnostic dans la RAM de secours, dans laquelle le résultat de diagnostic montrant une anomalie détectée pendant l'installation de l'unité de commande électronique (1) dans le véhicule reste dans la RAM de secours (9).
     
    2. Unité de commande électronique (1) selon la revendication 1, dans laquelle le stockage d'informations d'autorisation est une zone de mémoire prédéterminée dans la mémoire non volatile.
     
    3. Unité de commande électronique (1) selon la revendication 2, dans laquelle

    la zone de mémoire prédéterminée est une parmi une partie de la zone de mémoire pour stocker les données d'anomalie et une totalité de la zone de mémoire pour stocker les données d'anomalie dans la mémoire non volatile,

    l'unité de commutation d'autorisation réécrit des données dans la zone de mémoire prédéterminée d'une valeur initiale qui est définie avant l'installation de l'unité de commande électronique (1) dans le véhicule à une valeur spécifique qui est différente des données d'anomalie lorsqu'il est déterminé que le dispositif installé dans le véhicule est dans l'état normal,

    des données ayant la valeur initiale dans la zone de mémoire prédéterminée indiquent la non-autorisation du stockage des informations d'anomalie, et

    des données n'ayant pas la valeur initiale dans la zone de mémoire prédéterminée indiquent l'autorisation du stockage des informations d'anomalie.


     
    4. Unité de commande électronique (1) selon l'une quelconque des revendications 1 à 3, comprenant en outre :

    une unité de réponse (17) configurée pour, lorsqu'un signal de demande transmis d'un dispositif externe est reçu à condition que les informations d'autorisation indiquent l'autorisation du stockage des informations d'anomalie, transmettre un signal de réponse en réponse au signal de demande au dispositif externe, dans laquelle

    le signal de demande demande des données dans la zone de mémoire qui est utilisée pour stocker les informations d'anomalie dans la mémoire non volatile, et

    le signal de réponse comprend des données dans la zone de mémoire qui est utilisée pour stocker les informations d'anomalie vers le dispositif externe.


     
    5. Unité de commande électronique (1) selon la revendication 1, comprenant des moyens pour effectuer le diagnostic du dispositif installé dans le véhicule avant l'expédition du véhicule.
     
    6. Unité de commande électronique (1) selon la revendication 1, dans laquelle

    la mémoire non volatile a une valeur initiale stockée dans toutes les zones de mémoire dans un état de préinstallation dans le véhicule,

    l'unité de commande électronique (1) comprenant des moyens pour autoriser le stockage d'un résultat de diagnostic par l'unité de diagnostic dans la mémoire non volatile lorsqu'une modification de la valeur initiale est détectée durant une période suivant l'installation de l'unité de commande électronique (1) dans le véhicule et avant l'expédition du véhicule.


     




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    Cited references

    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description