Abstract:
A vehicle diagnosing apparatus, a vehicle diagnosing system, and a diagnosing method enable the determination of completion of a repair or part replacement on a vehicle while adapting to changes in environment and overcoming temporal or spatial restrictions. The vehicle diagnosing apparatus reads diagnostic information from an on-board diagnosing unit on the vehicle that detects an abnormality in an on-board device. A result of a maintenance work performed on the on-board device is finalized by a maintenance result finalizing unit. A determination unit determines the appropriateness of the finalized maintenance work result with reference to determination information stored in a database that is continuously updated. The result of the determination is indicated by a notifying unit. Analogy is used to obtain the diagnostic information when the on-board device requires a long time or a certain condition to provide accurate diagnostic information.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention generally relates to vehicle diagnosing apparatuses, vehicle diagnosing systems, and diagnosing methods for determining the presence or absence of an abnormality in a vehicle. 
         [0003]    2. Description of the Related Art 
         [0004]    There are some vehicles, such as cars, equipped with a diagnostic device for detecting an abnormality in various on-board sensors or actuators (hereafter referred to as “diagnosed parts”). The diagnostic device monitors the status of the diagnosed parts. Upon detection of an abnormality in a diagnosed part, the diagnostic device may save abnormality information within the device or transmit the abnormality information to a server. 
         [0005]    Japanese Patent No. 3799795 discusses a vehicle diagnosing system in which abnormality information is collected by a server. A user may voluntarily bring his or her vehicle with an abnormality into a service shop or the like. Upon elimination of the abnormality in the service shop or the like, “dealt-with” information is transmitted to the server so that an unnecessary transmission of a repair request to the user can be avoided. 
         [0006]    After a part causing the abnormality is repaired or replaced, the service shop determines whether the repair or the part replacement is complete based on a result of diagnosis of a diagnosed part using a diagnosing tool (hereafter referred to as “repair completion determination”). 
         [0007]      FIG. 6  schematically shows a repair completion determination process according to a related art. A repairer R at a service shop removes a defective part from a vehicle  11  (i). The repairer R then attaches an appropriate repair part to the vehicle  11  (ii). The repairer R diagnoses a diagnosed part (which is not necessarily the repair part with which the defective part has been replaced) using a diagnosing tool  15  (iii). The repairer R then confirms a behavior of the vehicle  11  based on his or her experience, or makes sure that the repair is in accordance with a manual or the like (iv). When the vehicle  11  is ascertained as being in a normal condition, the repairer R returns the vehicle  11  to the user U (v). 
         [0008]    In such a repair completion determination system which is based on a diagnosed result obtained from the diagnosed part using the diagnosing tool  15 , a predetermined determination standard is stored in the diagnosing tool  15 , and the diagnosed result is compared with the determination standard. Consequently, it is difficult to ascertain with the diagnosing tool  15  an incident or phenomenon that was not known or expected at the time of drawing up the determination standard stored in the diagnosing tool  15 . 
         [0009]    For example, a vehicle may be determined as being in a normal condition upon completion of a first repair with the diagnosing tool  15 . It is possible, however, that an event or a circumstance that was not considered in the determination standard at the time of the first repair may occur or arise several years after a repair part was attached to the vehicle during the first repair. For example, the upper-limit vehicle speed may be changed by a change in traffic law, or the environment in which the vehicle or the repair part is used may change over time. 
         [0010]    The diagnosed result obtained with the diagnosing tool  15  only concerns the individual diagnosed part. Actually, even when the diagnosed result of a particular diagnosed part is normal, whether the repair or part replacement has been normally completed must be comprehensively determined in view of the appropriateness of not just the diagnosed part alone but also other relevant vehicle parts under every possible circumstance. 
         [0011]    However, it is not always possible to consider or reproduce such “every possible circumstance” under the available repair conditions that are usually constrained both temporally and spatially. Spending a long time in trying to consider all such possible circumstances may not be realistic from the viewpoint of the vehicle user waiting for the completion of the repair. 
         [0012]      FIG. 7  shows a table of diagnosed parts and the time required to diagnose each of them using the diagnosing tool  15 . As shown in  FIG. 7 , it takes 1.0 sec to diagnose a sensor A, and 2.0 sec to diagnose a sensor B. For a sensor C, it takes 80 hours of a continuous run of the vehicle, before an accurate diagnosed result indicating a normality or an abnormality can be acquired. However, the continuous run of 80 hours for a diagnosis is unrealistic. As to a system Q, no diagnosed result is acquired because the system Q requires a high-temperature environment (such as 40° C.) or a low temperature environment (such as minus 30° C.) to acquire an accurate diagnosed result. 
         [0013]    If a repair cannot be completed unless such extremely limited environments as mentioned above are reproduced in a service shop or the like, the repair is virtually un-completable. 
         [0014]    Thus, in the conventional repair completion determination process, whether a repair or a part replacement has been normally completed is determined directly from a diagnosed result obtained with the diagnosing tool  15 . As a result, it has been difficult to make a repair completion determination in which considerations are given to various circumstances of use of the repair part that are not initially assumed, such as an event or an environment change that becomes relevant only a long time afterward. 
       SUMMARY OF THE INVENTION 
       [0015]    It is a general object of the present invention to provide a vehicle diagnosing apparatus, a vehicle diagnosing system, and a diagnosing method whereby one or more of the aforementioned problems are eliminated. 
         [0016]    A more specific object of the present invention is to provide a vehicle diagnosing apparatus, a vehicle diagnosing system, and a diagnosing method whereby completion of a repair or a part replacement can be determined while adapting to changes in the environment or reducing temporal or spatial constraints. 
         [0017]    According to an aspect of the present invention, a vehicle diagnosing apparatus for detecting an abnormality in a first vehicle includes a maintenance result finalizing unit configured to read diagnostic information from the first vehicle after a maintenance work is performed on an on-board device of the first vehicle, and configured to finalize a result of the maintenance work based on the diagnostic information; a storage unit configured to store determination information for determining an appropriateness of the result of the maintenance work finalized by the maintenance result finalizing unit; a determination unit configured to determine the appropriateness of the finalized result of the maintenance work with reference to the determination information in the storage unit; and a notifying unit configured to provide a notification of a result of the determination made by the determination unit. 
         [0018]    In a preferred embodiment, the vehicle diagnosing apparatus further includes a parameter generating unit that generates the determination information based on diagnostic information about the first vehicle and/or diagnostic information about a second vehicle before the maintenance work is performed on the on-board device of the first vehicle. 
         [0019]    Thus, the determination information can be adapted to various changes that may occur since when the determination information is initially drawn up. Thus, the appropriateness of the maintenance work on the on-board device, which is determined with reference to the determination information, can be accurately determined. 
         [0020]    According to another aspect of the present invention, a vehicle diagnosing system includes a server, an on-board diagnosing unit mounted on a first vehicle or a second vehicle or both, and a vehicle diagnosing apparatus for detecting an abnormality in the first vehicle. The server is configured to receive diagnostic information from the on-board diagnosing unit of the first vehicle and/or the second vehicle. The determination information stored in the storage unit of the vehicle diagnosing apparatus is generated from the diagnostic information about the first vehicle and/or the second vehicle collected in the server. 
         [0021]    According to yet another aspect of the present invention, a vehicle diagnosing method for detecting an abnormality in a first on-board device of a first vehicle includes the steps of reading diagnostic information from the first vehicle after a maintenance work is performed on the first on-board device of the first vehicle; finalizing a result of the maintenance work based on the diagnostic information obtained from the first vehicle after the maintenance work; storing determination information for determining an appropriateness of the result of the maintenance work finalized in the finalizing step; determining the appropriateness of the finalized result of the maintenance work with reference to the determination information stored in the storing step; and providing a notification of a result of the determination made in the determination step. 
         [0022]    In accordance with a preferred embodiment, the step of generating the determination information includes acquiring diagnostic information from a second on-board device of the first vehicle which diagnostic information is correlated with the diagnostic information about the first on-board device; and estimating the diagnostic information about the first on-board device based on the diagnostic information about the second on-board device. 
         [0023]    Thus, the diagnostic information about the first on-board device (diagnosed part) that exhibits accurate diagnostic information only after a long time or under a very limited condition can be estimated from the second on-board device from which accurate diagnostic information correlated with that of the first on-board device can be more readily acquired. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    These and other objects, features and advantages of the invention will be apparent to those skilled in the art from the following detailed description of the invention, when read in conjunction with the accompanying drawings in which: 
           [0025]      FIG. 1  illustrates how a repair completion determination is made according to an embodiment of the present invention; 
           [0026]      FIG. 2  shows block diagrams of an example of an on-board diagnosing apparatus  30  and a repair result determination apparatus  16 ; 
           [0027]      FIG. 3  shows an example of normal value information; 
           [0028]      FIG. 4  shows a flowchart of a procedure for determining whether a repair of a vehicle is completed; 
           [0029]      FIG. 5  schematically shows a repair result determination system according to an embodiment of the present invention; 
           [0030]      FIG. 6  illustrates a repair completion determination process according to a related art; and 
           [0031]      FIG. 7  shows a table of diagnosed parts diagnosed by a diagnosing tool and the time it takes to diagnose each diagnosed part using the diagnosing tool according to the related art. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0032]    Hereafter, preferred embodiments of the present invention are described with reference to the drawings. 
         [0033]      FIG. 1  schematically shows how a repair completion determination is made according to an embodiment. In the present embodiment, instead of the aforementioned diagnosing tool  15  according to the related art, a repair result determination apparatus  16  is used to diagnose a vehicle  11 . Also, instead of the repairer R, the repair result determination apparatus  16  determines whether a repair is complete. 
         [0034]    The repair result determination apparatus  16 , which may be installed in a service shop  20 , has normal value information stored in advance with reference to which diagnostic information about a diagnosed part may be determined as being normal. By comparing the normal value information and the diagnostic information, it is determined whether the repair has been normally completed. Thus, the temporal or spatial constraints according to the related art under which the determination as to whether a diagnosed result is normal needs to be made can be eliminated. 
         [0035]    The normal value information defines a normal range of diagnostic information about each of diagnosed parts. The diagnosed parts may include those for which acquisition of diagnostic information takes a long time, or those for which no diagnosed result can be obtained unless in a certain vehicle status. Thus, a diagnosed result for a diagnosed part can be acquired in the service shop  20  (which may include a service facility of a car dealer), and then whether a repair has been normally completed can be determined in the service shop 
         [0036]    If the amount of error between the diagnostic information and the normal value information is within a predetermined value, the repairer R may return the vehicle  11  to a user U. If the error amount is outside the predetermined value, the repairer R can check a predetermined diagnosed part again based on the diagnostic information. Thus, the completion of the repair can be accurately determined. 
         [0037]    As shown in  FIG. 1 , in order to store the normal value information in the repair result determination apparatus  16  in advance, each of various vehicles A through C transmits its own diagnostic information to a server  14  from an on-board diagnosing unit  30  with which each vehicle is equipped. The diagnostic information may indicate a detection of normality and/or that of abnormality of a diagnosed part. 
         [0038]    By collecting a large volume of normal diagnostic information, a range of diagnostic information that a diagnosed part would take in a normal state can be defined. By collecting a large volume of abnormal diagnostic information, a range of diagnostic information that a diagnosed part would take in an abnormal state can be defined. 
         [0039]    The normal diagnostic information may be periodically transmitted, while the abnormal diagnostic information may be transmitted only upon detection of an abnormality. 
         [0040]    The server  14  may be provided by a computer having a central processing unit (CPU). The server  14  includes a parameter generating unit  17  that generates normal value information  52  by conducting data mining on the normal diagnostic information and the abnormal diagnostic information. Data mining refers to the extraction of useful information from a large volume of data, a database, and the like. 
         [0041]    The server  14  may transmit the normal value information  52  to the repair result determination apparatus  16  each time the normal value information  52  is updated. The server  14  may also transmit the normal value information to the repair result determination apparatus  16  in response to an inquiry from the service shop  20 . 
         [0042]    Alternatively, the parameter generating unit  17  may be disposed in the repair result determination apparatus  16 , so that the repair result determination apparatus  16  can perform data mining. In this case, the server  14  transmits the normal diagnostic information and the abnormal diagnostic information to the repair result determination apparatus  16  as is. 
       (On-Board Diagnosing Unit) 
       [0043]      FIG. 2  shows a block diagram of the on-board diagnosing unit  30  and the repair result determination apparatus  16 . The on-board diagnosing unit  30  includes a communication device  31 , a diagnosed part  32  (there may be more than one diagnosed part  32 ), and a diagnostic electronic control unit (ECU)  33 , which are connected via a multiplex communication network. The multiplex communication network may be based on a communication protocol such as a controller area network (CAN), a Local Interconnect Network (LIN), and the like. A high-speed CAN may be employed for powertrain-system electronic parts (such as for the engine and brakes). An intermediate-speed CAN may be used for body-system electronic parts (such as for the doors and seats). 
         [0044]    The on-board diagnosing unit  30  is controlled by the diagnostic ECU  33 . The diagnostic ECU  33  may be a computer including a CPU, a random access memory (RAM), and a read-only memory (ROM). The diagnostic ECU  33  collects diagnostic information about the diagnosed part  32 , and transmits the diagnostic information to the server  14  via the communication device  31  or to the repair result determination apparatus  16  via a connector  34 . 
         [0045]    The on-board diagnosing unit  30  includes a diagnostic information collecting unit  35 , a first diagnostic information transmission unit  36 , and a second diagnostic information transmission unit  37 . The diagnostic information collecting unit  35  may be realized by the CPU of the on-board diagnosing unit  30  executing a program. 
         [0046]    The diagnosed part  32  may include one or more sensors or actuators for controlling various onboard devices. The diagnosed part  32  is controlled by another ECU connected to the multiplex communication network. The diagnosed part  32 , when connected to the engine ECU, may include an A/F (air-fuel ratio) sensor, a rotation speed sensor, an airflow meter, a water temperature sensor, or a throttle opening sensor. The diagnosed part  32 , when connected to the brake ECU, may include a wheel speed sensor, a G sensor, a pump motor, or a hydraulic pressure sensor. 
         [0047]    The ECU connected to the diagnosed part  32  has a self-diagnosis function for the sensor or actuator in the diagnosed part  32 . When an abnormality is detected, the self-diagnosis function generates diagnostic information indicating a location and nature of the abnormality. The diagnostic information is then stored in the ECU that manages the diagnosed part  32 , and/or in the diagnostic ECU  33 . 
         [0048]    The diagnostic information is information useful for diagnosing the vehicle  11 . The diagnostic information may merely indicate the presence or absence of an abnormality, or it may indicate a location and extent of a failure. The diagnostic information may further include operation data before and after the development of the failure, or indicate the date and time when the abnormality arose. 
         [0049]    When the diagnosed part  32  has no abnormality (i.e., when it is normal), the diagnostic information collecting unit  35  requests the ECU for the diagnosed part  32  to diagnose the sensors or actuators at predetermined time periods, in order to collect diagnostic information. Such diagnostic information is useful in diagnosing the vehicle  11  as is the diagnostic information indicating the detection of an abnormality. 
         [0050]    The diagnostic information collecting unit  35  may perform a statistical processing on the diagnostic information that has been collected at predetermined time periods to extract characteristic information out of the diagnostic information. In this way, the volume of data that needs to be transmitted can be reduced. The statistical processing may involve the calculation of average value s, maximum value s, minimum value s, median value s, and/or a variance of detection signals such as voltage value s or current value s obtained by the sensors or actuators. 
         [0051]    Such statistical processing may be performed in either the server  14  or the repair result determination apparatus  16 . For example, the parameter generating unit  17  may perform data mining on average value s for vehicles A through C obtained by statistical processing, so that the normal value information  52  for a relevant sensor can be obtained from the diagnostic information at normal time. In accordance with the present embodiment, diagnostic information may or may not be subjected to statistical processing. 
         [0052]    The first diagnostic information transmission unit  36  transmits the diagnostic information to the server  14  via the communication device  31 . The diagnostic information that is transmitted is associated with information identifying the relevant system of the vehicle  11 , such as the engine system, the brake system, or the safety equipment system. The information identifying the vehicle system may include the engine type number and the vehicle number. 
         [0053]    Such system identifying information is required because the diagnostic information varies from one vehicle system to another, and data mining needs to be performed on a system by system basis. 
         [0054]    The diagnostic information may be transmitted on a vehicle by vehicle basis, so that the normal value information optimized for the individual vehicle  11  can be generated. 
         [0055]    The diagnostic information when the diagnosed part  32  is normal may be transmitted either periodically, such as once or more times a day, or irregularly, such as immediately after turning the ignition on or off. 
         [0056]    The communication device  31  connects to the network  13  via a base station  12  for a cellular phone network, or an access point of a wireless LAN or a WiMAX (Worldwide Interoperability for Microwave Access), in order to communicate with the server  14 . 
         [0057]    The transmission of the diagnostic information may be based on a known communication protocol, such as the Point-to-Point protocol (PPP), or the upper-layer Transmission Control Protocol/Internet Protocol (TCP/IP). The network  13  may include a communication network or the Internet. 
         [0058]    The connector  34 , which may be installed adjacent the instrument panel or the steering column of the vehicle, provides a physical or software interface with the repair result determination apparatus  16 . The connector  34  may be in compliance with OBDII (On-Board Diagnostic systems stage II). 
       (Repair Result Determination Apparatus) 
       [0059]    Still referring to  FIG. 2 , the repair result determination apparatus  16  includes, in addition to the function of the diagnosing tool  15 , a repair result finalizing unit  51  and a determination unit  53 . The repair result finalizing unit  51  finalizes a repair result. The determination unit  53  determines whether a repair is completed based on the finalized result and the normal value information  52 . In the present embodiment, the repair result determination apparatus  16  is described as being an embodiment of a computer, on the assumption that the repair result determination unit  51  is realized by a program. 
         [0060]    The repair result determination apparatus  16  includes a CPU  42 , a storage unit  43 , a RAM  44 , a ROM  45 , a display control unit  46 , a storage medium attachment unit  47 , a network interface card (NIC)  48 , and an input device  49 , which are all connected via a bus. The CPU  42  reads a program stored in the storage unit  43  and executes it using the RAM  44  as a working area, in order to provide the functions of the repair result finalizing unit  51 , the determination unit  53 , and the parameter generating unit  17 . The CPU  42  also controls the repair result determination apparatus  16  comprehensively. 
         [0061]    The input device  49  may include a keyboard and mouse, and a voice input device. The input device  49  is used for the input of various operational instructions from a repairer. The storage medium attachment unit  47  reads information stored in a storage medium  40 , such as a compact disc (CD), a digital versatile disc (DVD), or a flash memory. The storage medium attachment unit  47  also writes information possessed by the repair result determination apparatus  16  in the storage medium  40 . The NIC  48  is a communication device for connection with the network  13 . The NIC  48  receives information transmitted by the server  14  in accordance with a predetermined protocol. 
         [0062]    In an embodiment where the normal value information  52  is generated in the repair result determination apparatus  16 , the normal value information  52  in the storage unit  43  may be updated as needed. In another embodiment where the normal value information  52  is generated by the server  14 , the repair result determination apparatus  16  may receive the normal value information  52  from the server  14  via the NIC  48 , and updates the normal value information  52  stored in the storage unit  43 . Alternatively, the normal value information  52  may be recorded in the storage medium  40  by the server  14 , and the storage medium  40  distributed by the server  14  may be read by the repair result determination apparatus  16 . 
         [0063]    The repair result determination apparatus  16  also includes a data communication unit  41  that can be connected with the connector  34  in the vehicle  11  via radio or wire for communication with the diagnostic ECU  33 . 
         [0064]    For example, the repairer connects a cable compatible with the standard of the data communication unit  41  to the connector  34 , and then operates the input device  49  to request a transmission of diagnostic information from the diagnostic ECU  33 . Then, the second diagnostic information transmission unit  37  transmits the diagnostic information collected by the diagnostic information collecting unit  35  to the repair result determination apparatus  16  via the data communication unit  41 . 
         [0065]    For wireless communication between the repair result determination apparatus  16  and the diagnostic ECU  33 , any of various wireless technologies, such as dedicated short range communications (DSRC), Bluetooth, or wireless LAN may be used. 
         [0066]    A diagnosis code indicating the diagnosed part  32  with an abnormality may be acquired. However, because in the present embodiment it is determined whether a repair is completed after a repair part is attached, the diagnosis code is in many cases not detected upon acquisition of diagnostic information. 
       (Normal Value Information) 
       [0067]    The normal value information  52  is described. The parameter generating unit  17  in the server  14  generates a parameter value for each diagnosed part  32  that can be considered as being normal, by subjecting the diagnostic information acquired from the vehicles A through C to pattern extraction, classification, regression analysis, etc. For example, a normal value of a detection signal outputted by the diagnosed part  32  of each vehicle is converted into a parameter value. In this way, normal value information  52  for most of the diagnosed parts  32  can be obtained. 
         [0068]    If the diagnosed part  32  takes a long time before its diagnostic information can be acquired, one or more diagnosed parts  32  may be determined from which diagnostic information that correlates well with that from the target (time-taking) diagnosed part  32  can be acquired in a short time. Specifically, the one or more correlating diagnosed parts  32  should exhibit diagnostic information that correlates well with the normal-state diagnostic information that the target diagnosed part  32  would exhibit during use of the vehicle (such as when the vehicle ignition is on or an accessory switch alone is on, as well as when the vehicle is running). 
         [0069]    The parameter generating unit  17  can then determine a relational expression for determining (estimating) a detection signal from the target diagnosed part  32  from a detection signal from the correlating diagnosed part. Using such relational expression, the parameter generating unit  17  can generate a normal-state parameter value of the target (time-taking) diagnosed part  32 . 
         [0070]    Similarly, for a diagnosed part  32  from which diagnostic information can be acquired only in a certain running status, one or more diagnosed parts  32  may be determined from which diagnostic information that correlates well with the normal-state diagnostic information that would be detected from the target diagnosed part  32  in the predetermined running status and that can be readily acquired. 
         [0071]    The parameter generating unit  17  can then determine a relational expression for determining (estimating) a detection signal from the target diagnosed part  32  based on the detection signal from the correlating diagnosed part. In this way, the parameter generating unit  17  can generate a normal-state parameter value of the target diagnosed part  32  from which the diagnostic information cannot be readily acquired. For such extraction of correlation or determination of the relational expression, data mining may be used. 
         [0072]    The parameter value may be generated using the diagnostic information indicating an abnormality. If one or more diagnosed parts  32  that exhibit diagnostic information correlated with the diagnostic information of the diagnosed part  32  that indicates an abnormality can be extracted, this will be effective for the diagnosed part  32  from which the abnormal diagnostic information can be acquired only after a long time or in a certain running status. 
         [0073]    Namely, the abnormal-state diagnostic information of the diagnosed part  32  that is only available after a long time or in a certain running status can be determined (estimated) from the diagnostic information of another diagnosed part that is correlated with the diagnostic information for the target diagnosed part  32  and that can be more readily acquired in the service shop  20 . 
         [0074]      FIG. 3  shows a table including “Normal-state parameter value”, which is an example of the normal value information  52 . The “Diagnosed part” indicates each diagnosed part  32 . The “After-repair parameter value”, which is generated from the diagnostic information acquired after a repair, is shown in the column to the right of the normal-state parameter value The amount of “Error” may be calculated as follows: 
         [0000]      {(Normal-state parameter value−After-repair parameter value)/Normal-state parameter value}×100 
         [0075]    An acceptable value of the error amount may be within several to several dozen percents. The normal-state parameter value may be given a certain margin corresponding to such an acceptable value in advance. Depending on the error amount from the normal-state parameter value, the probability of the presence of an abnormality may be indicated in percentage terms. For example, the error amount of ±20% from the normal-state parameter value may indicate the 0% probability of abnormality; and the error amount of ±20 to 30% may indicate the 10% probability of abnormality. 
         [0076]    In the example of  FIG. 3 , the error amount between the normal-state parameter value and the after-repair parameter value is small for each of the sensors A through C; thus, it is determined that the repair of each of these sensors is normally completed. As to the system Q, the error amount between the normal-state parameter value and the after-repair parameter value is large, so that it is determined that the repair of the system Q may possibly be incomplete. The system Q in  FIG. 3  may be the same as the system Q of  FIG. 6 . 
         [0077]    Thus, the diagnostic information of the diagnosed part  32  that can only be detected in a certain running status (such as the vehicle speed being greater than zero, or the vehicle running on a highway), such as the system Q of  FIG. 6 , can be determined in the service shop  20  within a practical time. 
         [0078]    Instead of the normal-state parameters being indicated in numerical values as in the example of  FIG. 3 , a set of the diagnostic information about plural diagnosed parts  32  that correlate with a particular diagnosed part  32  may be clustered into normal and abnormal groups. Then, the diagnostic information of the same set acquired by the data communication unit  41  may be subjected to pattern recognition to determine whether the diagnostic information is classified into the normal or the abnormal group, to thereby determine whether the repair is complete. 
       (Finalization of Repair Result) 
       [0079]    The repair result finalizing unit  51  generates the after-repair parameter value from the diagnostic information read from the vehicle  30 , using the same method as used when the parameter generating unit  17  of the server  14  generated the normal-state parameter value. This after-repair parameter value is considered a final result for the repair. The determination unit  53  then determines whether the repair has normally been completed by comparing the normal-state parameter value and the after-repair parameter value. 
         [0080]    In another embodiment, the server  14  may include the repair result finalizing unit  51 , the determination unit  53 , and the normal value information  52 . In this embodiment, the diagnostic information received by the data communication unit  41  is transmitted to the server  14 , and the repair result determination apparatus  16  receives a determination result from the server  14 . In this case, the repair result determination apparatus  16  may be configured in the same way as the conventional diagnosing tool  15  shown in  FIG. 16 . 
       (Operational Procedure for the Repair Result Determination Apparatus) 
       [0081]      FIG. 4  shows a flowchart of a process performed by the repair result determination apparatus  16  in determining whether a repair is completed. The process of  FIG. 4  may be started by connecting the data communication unit  41  and the connector  34 , and entering a predetermined operation via the input device  49 . 
         [0082]    The repair result finalizing unit  51  acquires diagnostic information from the on-board diagnosing unit  30  of the vehicle  11  (S 10 ). The diagnostic information has been acquired by the diagnostic ECU  33  requesting the ECU that controls the one or more diagnosed parts  32  to diagnose the sensors or actuators. 
         [0083]    Upon acquisition of the diagnostic information from all of the diagnosed parts  32 , the repair result finalizing unit  51  converts the diagnostic information into the after-repair parameter value (S 20 ). The determination unit  53  then refers to the normal value information  52  to determine, for each diagnosed part  32 , whether the error amount between the normal-state parameter value and the after-repair parameter value exceeds a predetermined value (S 30 ). Alternatively, the determination unit  53  may access the server  14  to refer to the normal value information  52  therein, in order to make the above determination. 
         [0084]    If a diagnosed part  32  whose error amount exceeds the predetermined value is detected (“Yes” in S 30 ), the repair result finalizing unit  51  saves information about the diagnosed part  32  in the storage unit  43 , or the like (S 40 ). The determination in step S 30  is repeated on the remaining diagnosed parts  32 . 
         [0085]    When there is no more diagnosed part  32  whose error amount exceeds the predetermined value (“No” in S 30 ), the determination unit  53  outputs determination results (S 50 ). The determination results may be displayed on the display  50  in the form of a message. For example, if there was no diagnosed part  32  whose error amount exceeded the predetermined value, the message may read “Repair completed”. If there was a diagnosed part  32  whose error amount exceeded the predetermined value, the message may read “Possible incomplete repair: sensor A”. The determination results may be stored in the storage unit  43  or the storage medium  40 . 
         [0086]    The repairer can view such a message and decide to either return the vehicle  11  to the user, repeat the procedure of  FIG. 4 , or repair the relevant diagnosed part  32 . 
         [0087]    The parameter generating unit  17  then subjects the normal value information  52  and the after-repair parameter value to data mining, and updates the normal value information  52  (S 60 ). Thus, the normal value information  52  can be updated based on the result of maintenance of the vehicle  11 . 
         [0088]    Thus, in accordance with the present embodiment, the repair result determination apparatus  16  has the normal value information  52  stored in advance by which the diagnostic information outputted by the diagnosed part  32  in a normal state is defined. And it can be determined whether a repair is completed for a diagnosed part  32  of which the acquisition of diagnostic information takes a long time or requires a certain running status. 
         [0089]    In other words, it can be determined, within a realistic time and environment, whether a repair is completed for the diagnosed part  32  that is associated with temporal or spatial restrictions as regards the determination of completion of diagnosis. Even if the environment changes over the years of use, the diagnosed part  32  can be diagnosed in a manner adapted to the change in the environment because of the accumulation of diagnostic information adapted to various environments. 
         [0090]    After the completion of a repair is once determined in the service shop  20 , the validity of a past repair result can be verified when the vehicle is brought into the service shop  20  subsequently (for the next regular inspection or the mandatory safety inspection). 
         [0091]    In another embodiment, when the result of a repair of the diagnosed part  32  is determined by the repair result determination apparatus  16 , the determination result may be transmitted to the server  14 . In this way, the determination result can be utilized for the subsequent data mining. The determination result may be transmitted to either the server  14  or the repair result determination apparatus  16  where data mining is performed. 
         [0092]      FIG. 5  schematically shows a repair result determination system, in which units or components similar to those shown in  FIG. 1  are designated with similar reference numerals and their further description is omitted. 
         [0093]    Upon detection of an abnormality in the diagnosed part  32 , the on-board diagnosing unit  30  in the vehicle  11  transmits diagnostic information indicating abnormality (to be hereafter referred to as “abnormality diagnosis information”) to the server  14 . The abnormality diagnosis information may include the vehicle number and the diagnosis code indicating the diagnosed part  32  having the abnormality. 
         [0094]    A user of the vehicle  11 , noting the abnormality diagnosis information displayed on the instrument panel or the like, may bring the vehicle  11  into the service shop  20 . In the service shop  20 , the diagnosed part  32  having the abnormality is identified by the repair result determination apparatus  16  based on the diagnosis code or the like, and a repairer replaces the defective component with a repair part. 
         [0095]    It is then estimated whether the relevant repair is completed as in the foregoing embodiment. If it is presumed that the repair is complete, the repair result determination apparatus  16  transmits abnormality elimination information to the server  14  via the NIC  48 , together with the vehicle number. The abnormality elimination information may also include information about the repair part with which the defective part has been replaced. 
         [0096]    The server  14  then collates the abnormality diagnosis information with the abnormality elimination information, and accumulates the information about the repair part necessary for eliminating the abnormality indicated by the abnormality diagnosis information. 
         [0097]    Particularly, when a diagnosed part  32  that is different from the diagnosed part  32  indicated by the diagnosis code is replaced with a repair part, the server  14  can perform a more appropriate data mining based on the relationship between the indicated diagnosed part and the replaced diagnosed part. Thus, the server  14  can generate the normal value information  52  so that a replacement part for similar abnormality diagnosis information can be reliably identified. 
         [0098]    Thus, in accordance with the present embodiment, the abnormality elimination information is transmitted to the server  14 . Thus, in addition to the effects of the foregoing embodiment, the server  14  can generate normal value information  52  more appropriate for the determination of completion of a diagnosis. 
         [0099]    While the present invention has been described with reference to specific embodiments, the invention is not limited by such embodiments, and various changes or modifications may occur to those skilled in the art without departing from the scope of the invention. 
         [0100]    The present application is based on the Japanese Priority Application No. 2008-041953 filed Feb. 22, 2008, the entire contents of which are hereby incorporated by reference.