Abstract:
In a vehicle diagnostic method and an external diagnostic device, sensor detection values acquired by communicating with an ECU are measured to determine whether the values are in a normal range while a vehicle is idling. After an engine is started, an operation to measure soundness is prohibited at least until the sensor detection values including the engine rotational frequency reach a threshold value region indicating the completion of the warm-up operation. The fluctuation state of the sensor detection values is displayed on an operation screen until the sensor detection values reach the threshold value region.

Description:
TECHNICAL FIELD 
     The present invention relates to a vehicle diagnostic method and an external diagnostic apparatus (device) for making a diagnosis of the health state of a vehicle (deterioration diagnosis). 
     BACKGROUND ART 
     If a vehicle suffers a fault, the vehicle is taken to a repair shop of a dealer or the like. The operator (technician) who is responsible for repairing the vehicle connects an electronic control unit (hereinafter referred to as “ECU”) on the vehicle to an external diagnostic apparatus, reads fault data (fault code) from the ECU, analyzes a defective location or a fault source, and makes necessary repairs or an necessary adjustment. 
     When vehicles are manufactured, they are checked at the final inspection stage of the production process to see if their sensors or ECUs are functioning properly or not. While vehicles to be diagnosed are conveyed one after another at the final inspection stage, each of the vehicles is controlled to operate (idle) stably and then diagnosed collectively and efficiently {see S603 in FIG. 12, [0044], and [0045] of Japanese Laid-Open Patent Publication No. 09-210870 (hereinafter referred to as “JP09-210870A”)}. According to JP09-210870A, after a cable 5 of a vehicle diagnostic apparatus 2 is connected to each of successively conveyed vehicles, the vehicle diagnostic apparatus 2 automatically starts diagnosing the vehicle without displaying a menu screen ([0035]). 
     SUMMARY OF INVENTION 
     According to JP09-210870A, as described above, since diagnostic conditions are prepared for a vehicle diagnosis by controlling each of the successively conveyed vehicles to be diagnosed to operate (idle) stably, the vehicles can successively be diagnosed efficiently to see if their sensors or ECUs are functioning properly or not. 
     If a vehicle that has been used for many years is to be diagnosed for its health state (health diagnosis) for the purpose of preventing the vehicle from suffering faults, then the vehicle is taken to the repair shop of the dealer or the like and individually diagnosed as in the case where the vehicle suffers a fault. In the repair shop, the vehicle should preferably be measured in a stable operating condition, e.g., after it has been warmed up. 
     However, if a long waiting time is needed until a measurement starting condition is met, e.g., the vehicle has been warmed up, then the operator tends to fail to recognize that there is a possibility of occurrence of deterioration in parts related to, for example, the long waiting time until the measurement starting condition is met, the reason why the measurement starting condition cannot be met, and the measurement starting condition. Consequently, it is likely for the operator to have difficulty in diagnosing the health state of the vehicle with accuracy. 
     The present invention has been made in view of the above problems. It is an object of the present invention to provide a vehicle diagnostic method and an external diagnostic apparatus which are capable of diagnosing the health state of a vehicle highly accurately. 
     According to the present invention, there is provided a vehicle diagnostic method for diagnosing a vehicle by an external diagnostic apparatus acquiring detected sensor values of the vehicle from the vehicle via data communication between an electronic control unit mounted on the vehicle and the external diagnostic apparatus, wherein the detected sensor values include an engine rotational speed, and the external diagnostic apparatus carries out an idling confirming step of measuring whether or not the engine rotational speed is within a normal range for the vehicle that is idling, a health state measuring step of, when the vehicle is idling, measuring whether the detected sensor values acquired via communication with the electronic control unit are within normal ranges or not, a measurement inhibiting step of inhibiting the measurement of the health state measuring step, after an engine has started and until the detected sensor values including at least the engine rotational speed reach threshold value regions indicating completion of warming-up of the vehicle, and a varying state display step of displaying varying states of the detected sensor values on an operating screen until the detected sensor values reach the threshold value regions. 
     According to the present invention, since the measurement (health state measurement) of the health state measuring step using the detected sensor values is inhibited until the vehicle has been warmed up, the health state of the vehicle can be measured accurately. 
     While the health state of the vehicle is inhibited from being measured, the varying states of the detected sensor values for judging a condition for inhibiting the measurement of the health state are displayed. Therefore, the user can confirm the reason why the measurement of the health state is inhibited, as the varying states in the detected sensor values, and can visually confirm the changing situation and how it changes until the inhibition of the measurement of the health state is canceled. In addition, in a case where it is taking more time than usual until the inhibition of the measurement of the health state is canceled, the user can recognize which one of the detected sensor values does not satisfy a condition for canceling the inhibition of the measurement of the health state. Therefore, the user is enabled to know that some trouble has been occurring in relation to the detected sensor value that does not satisfy the condition for canceling the inhibition of the measurement of the health state. 
     According to the present invention, furthermore, it is judged whether the detected sensor values are within the normal ranges or not only if the vehicle is idling. It is thus possible to measure the health state under a condition where the engine is operating stably, and hence the health state can be measured highly accurately. 
     A first start button for giving an instruction to start the measurement of the health state measuring step may be displayed on the operating screen. The first start button may be displayed as inactive so as to be non-selectable during the measurement inhibiting step, and the first start button may be displayed as active so as to be selectable after the measurement inhibiting step has been ended. The varying states of the detected sensor values may be displayed together with the first start button that is displayed as inactive. 
     Therefore, the varying states of the detected sensor values (the engine rotational speed, etc.) are displayed together with the first start button that is displayed as inactive until the displayed first start button goes from inactive to active. Consequently, information about whether the health state is inhibited from being measured or not is given to the user in a plain fashion. In addition, since the user is enabled to know the progress status of warming-up of the vehicle based on the varying states of the detected sensor values (the engine rotational speed, etc.), the user can avoid wrong operations during the waiting time. 
     The detected sensor values may include a coolant water temperature of the engine in addition to the engine rotational speed, and the varying state display step may display, on the operating screen, the varying states of the engine rotational speed and the coolant water temperature as animation images. Thus, the user can easily confirm the varying states of the engine rotational speed and the coolant water temperature, and can effectively use the waiting time until the inhibition of the measurement of the health state is canceled. 
     When the external diagnostic apparatus is turned on, the external diagnostic apparatus may acquire the detected sensor values including the engine rotational speed and the coolant water temperature regardless of whether the engine has started or not. 
     When the first start button is displayed as inactive, a second start button for giving an instruction to start another diagnosis function may be displayed as active so as to be selectable on the operating screen. Therefore, it is possible to start another diagnosis function even before the preparations for the measurement of the health state are completed. The waiting time until the warming-up of the vehicle is completed can thus be used to perform another diagnosis function. 
     According to the present invention, there is also provided an external diagnostic apparatus for diagnosing a vehicle by acquiring detected sensor values of the vehicle through an electronic control unit mounted on the vehicle via data communication with the electronic control unit from outside of the vehicle, wherein the detected sensor values include an engine rotational speed, and the external diagnostic apparatus comprises an idling confirming unit for measuring whether or not the engine rotational speed is within a normal range for the vehicle that is idling, a health state measuring unit for, when the vehicle is idling, measuring whether the detected sensor values acquired via communication with the electronic control unit are within normal ranges or not, a measurement inhibiting unit for inhibiting the measurement of the health state measuring unit until the detected sensor values including at least the engine rotational speed reach threshold value regions indicating completion of warming-up of the vehicle, and a varying state display unit for displaying varying states of the detected sensor values on an operating screen after an engine has started and until the detected sensor values reach the threshold value regions. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a block diagram showing a general configuration of a fault diagnostic system having an external diagnostic apparatus according to an embodiment of the present invention; 
         FIG. 2  is a diagram showing an example of a diagnosis function selecting screen displayed with all diagnosis function selecting buttons being active; 
         FIG. 3  is a first flowchart of a processing sequence of the external diagnostic apparatus; 
         FIG. 4  is a second flowchart of the processing sequence of the external diagnostic apparatus; 
         FIG. 5  is a diagram showing an example of the diagnosis function selecting screen displayed with only a data view function execution button being active; 
         FIG. 6  is a diagram showing an example of a screen with an input box displayed for entering vehicle information; 
         FIG. 7  is a diagram showing an example of the diagnosis function selecting screen displayed with only a deterioration diagnosis function execution button being not active; 
         FIG. 8  is a diagram showing an example of a DTC (Diagnostic Trouble Code) and freeze data screen displayed which is used while a DTC and freeze data function is being performed; 
         FIG. 9  is a diagram showing an example of a visual display screen displayed which is used while a deterioration diagnosis function is being performed; and 
         FIG. 10  is a diagram showing an example of a list display screen displayed which is used while the deterioration diagnosis function is being performed. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     A. Embodiment: 
     [1. Configuration] 
     (1-1. Overall Configuration) 
       FIG. 1  shows in block form a general configuration of a fault diagnostic system  10  (hereinafter referred to as “system  10 ”) having an external diagnostic apparatus  14  (hereinafter referred to as “diagnostic apparatus  14 ”) according to an embodiment of the present invention. The system  10  includes a vehicle  12  (a motorcycle in the present embodiment) as a diagnostic target and the diagnostic apparatus  14  for making a fault diagnosis of the vehicle  12  from outside the vehicle  12 . 
     (1-2. Vehicle  12 ) 
     The vehicle  12  has an electronic control unit  20  (hereinafter referred to as “ECU  20 ”), an ignition switch (hereinafter referred to as “IGSW  22 ”) for controlling on and off of the ECU  20 , and various sensors  24 . The ECU serves to control an engine  26 , a transmission (not shown), a brake (not shown), etc. of the vehicle  12 . As shown in  FIG. 1 , the ECU  20  has an input/output unit  30 , a processor  32 , and a storage unit  34 . 
     The various sensors  24  include an engine rotational speed sensor  36  for detecting the rotational speed of the engine  26  (hereinafter referred to as “engine rotational speed Ne”) [rpm], and a water temperature sensor  38  for detecting the temperature of the coolant water of the engine  26  (hereinafter referred to as “coolant water temperature Tw”) [° C.]. 
     In the present embodiment, the engine  26  is a gasoline engine, and the vehicle  12  is a gasoline-powered vehicle. As described later, the vehicle  12  may be a vehicle such as a diesel engine vehicle, an electric vehicle, a hybrid vehicle, or the like. Though the vehicle  12  according to the present embodiment is a motorcycle, it may be a three-wheeled vehicle, a four-wheeled vehicle, a six-wheeled vehicle, or the like. 
     (1-3. External Diagnostic Apparatus  14 ) 
     (1-3-1. Overall Configuration) 
     The external diagnostic apparatus  14  has a tester  40  and a personal computer  42  (hereinafter referred to as “PC  42 ”). The diagnostic apparatus  14  is capable of making various diagnoses (including a health diagnosis) of the vehicle  12 . 
     (1-3-2. Tester  40 ) 
     The tester  40  is used in various diagnoses (inspections) as a communication interface to be connected to the ECU  20  of the vehicle  12  in a car dealer, a service shop, or the like, for reading data of the vehicle  12 . The tester  40  has a lower processing capability and a smaller storage capacity than the PC  42 , but is smaller in size and has better portability than the PC  42 . The tester  40  can make, by itself, various diagnoses (or inspections) on the vehicle  12  using various data (detected sensor values) read from the vehicle  12 , and can also save the read data and thereafter send them to the PC  42 . 
     As shown in  FIG. 1 , the tester  40  has a first cable  60  connected to the ECU  20  of the vehicle  12 , a second cable  62  connected to the PC  42 , an input/output unit  64  connected to the first cable  60  and the second cable  62  for inputting and outputting signals, a communication unit  66  for performing wireless communication with the PC  42 , an operating unit  68 , a processor  70  for controlling components of the tester  40 , a storage unit  72  for storing programs including control programs run by the processor  70  and data, and a display unit  74 . 
     The operating unit  68  has operating buttons, etc. for performing operating processes to send output commands (pseudo signals) to the ECU  20  or the various sensors  24  of the vehicle  12  when necessary. 
     The processor  70  has a data collecting and saving function  80  and a data output function  82 . The data collecting and saving function  80  is a function to collect various data (sensor output values) from the vehicle  12  through the ECU  20  and saving the collected data in the storage unit  72 . The data output function  82  is a function to output the various data saved in the storage unit  72  to the PC  42 . 
     The display unit  74  displays various data read from the ECU  20  on a monitor screen. 
     The first cable  60  may be replaced with a wireless communication function. The tester  40  and the PC  42  can communicate with each other through a wired communication link via the second cable  62  and also through a wireless communication link via the communication unit  66 . However, the tester  40  and the PC  42  may communicate with each other through either one of the wired communication link and the wireless communication link. 
     (1-3-3. PC  42 ) 
     The PC  42  has an input/output unit  90  connected to the second cable  62  for inputting and outputting signals, a communication unit  92  for performing wireless communication with the tester  40 , an operating unit  94  including a keyboard, a mouse, a touch pad, etc., not shown, a processor  96  for controlling components of the PC  42  and making various diagnoses, a storage unit  98  for storing programs including control programs, diagnostic programs, etc. run by the processor  96  and also storing data, and a display unit  100  for displaying various information. The PC  42  may comprise a commercially available laptop personal computer as hardware. 
     The processor  96  has a data viewing function  110 , a data list function  112 , a DTC and freeze data function  114  (hereinafter referred to as “DTC function  114 ”), a drive recorder function  116 , a deterioration diagnosis function  118 , and a function selecting function  120 . 
     The data viewing function  110  is a function to read, display, and edit data stored in the storage unit  98  of the PC  42 . The data list function  112  is a function to list and display data that can be acquired from the vehicle  12 . 
     The DTC function  114  is a function to display and edit fault codes (DTC: Diagnostic Trouble Code) and freeze data. If the ECU  20  detects a fault in the vehicle  12 , then it saves a corresponding DTC in the storage unit  34  as information indicating the contents of the fault. The DTC function  114  of the PC  42  makes it possible to display and edit a DTC read from the ECU  20  in the present diagnosis and also a DTC read from the ECU  20  in the past (see  FIG. 8 ). The freeze data represent detected sensor values related to a fault at the time the fault occurs, i.e., at the time the DTC is saved. 
     The drive recorder function  116  is a function to play and edit data from a drive recorder (not shown) in a case where the drive recorder is incorporated in the vehicle  12 . 
     The deterioration diagnosis function  118  is a function to diagnose the health state {operating state (including a deteriorating state)} of the vehicle  12  at the present time. Specifically, the deterioration diagnosis function  118  checks if the detected sensor values from the vehicle  12  are abnormal or not, i.e., if the sensors have excessively deteriorated or not. The detected sensor values refer to data (operating parameters) indicating operating states of various components of the vehicle  12 , and include not only output values from the sensors included in the various sensors  24 , but also values processed by the ECU  20  or processors, not shown, based on the output values from the sensors. 
     Diagnostic target items that can be diagnosed by the deterioration diagnosis function  118  may include an engine rotational speed Ne, a water temperature sensor voltage, a throttle sensor voltage, an intake gas temperature sensor voltage, an intake pressure sensor voltage, an atmospheric pressure sensor voltage, an amount of injected fuel, an ignition timing, an idling air control valve opening degree, a battery voltage, and an oil temperature sensor voltage. 
     The function selecting function  120  is a function to select which one of the above functions  110 ,  112 ,  114 ,  116 ,  118  to be performed in response to an operating action of the user. 
     The storage unit  98  includes a vehicle database  130  (hereinafter referred to as “vehicle DB  130 ”). The vehicle DB  130  stores information representing the model name of the vehicle  12 , the model year of the vehicle  12 , the place of destination of the vehicle  12 , the model code of the vehicle  12 , the identification information of the ECU (hereinafter referred to as “ECU ID”), and DTC and freeze data, etc. 
     For making various diagnoses of the vehicle  12  using the PC  42 , the first cable  60  of the tester  40  is connected to an unillustrated connector, i.e., a data link connector, disposed in the vehicle  12 . By use of the second cable  62  or the communication units  66 ,  92 , the ECU  20  and the PC  42  are made to be ready to communicate with each other. Thereafter, in response to the user operating the operating unit  94  of the PC  42 , the PC  42  makes various diagnoses (including a health diagnosis) of the vehicle  12 . 
     [2. Display Screen of PC  42 ] 
     As described above, the PC  42  has the data viewing function  110 , the data list function  112 , the DTC function  114 , the drive recorder function  116 , and the deterioration diagnosis function  118 . The PC  42  can make various diagnoses using these functions  110 ,  112 ,  114 ,  116 ,  118 . In order to allow the user to select either one of the functions  110 ,  112 ,  114 ,  116 ,  118 , the PC  42  (function selecting function  120 ) according to the present embodiment displays a display screen  200  shown in  FIG. 2  (hereinafter referred to as “diagnosis function selecting screen  200 ”, “function selecting screen  200 ”, or “screen  200 ”) on the display unit  100 .  FIG. 2  shows by way of example the screen  200  for selecting either one of the functions  110 ,  112 ,  114 ,  116 ,  118  in the present embodiment. 
     As shown in  FIG. 2 , the diagnosis function selecting screen  200  has five diagnosis function selecting buttons for reading data from the ECU  20 , i.e., a data view function execution button  210  (hereinafter referred to as “data view button  210 ”), a data list function execution button  212  (hereinafter referred to as “data list button  212 ”), a DTC and freeze data function execution button  214  (hereinafter referred to as “DTC button  214 ”), a drive recorder function execution button  216  (hereinafter referred to as “drive recorder button  216 ”), and a deterioration diagnosis function execution button  218  (hereinafter referred to as “deterioration diagnosis button  218 ”). 
     When the user selects the data view button  210  through the operating unit  94 , the data viewing function  110  is performed. When the user selects the data list button  212  through the operating unit  94 , the data list function  112  is performed. When the user selects the DTC button  214  through the operating unit  94 , the DTC function  114  is performed. When the user selects the drive recorder button  216  through the operating unit  94 , the drive recorder function  116  is performed. When the user selects the deterioration diagnosis button  218  through the operating unit  94 , the deterioration diagnosis function  118  is performed. 
     According to the present embodiment, if there is a diagnosis function that is permitted to be performed at that point in time, then the function selecting function  120  displays a selecting button corresponding to the diagnosis function as being active (selectable). On the other hand, if there is a diagnosis function that is not permitted to be performed at that point in time, then the function selecting function  120  displays a selecting button corresponding to the diagnosis function as being inactive (non-selectable). According to the present embodiment, furthermore, in order to make it easy for the user to distinguish between active and inactive selecting buttons, the function selecting function  120  displays the inactive selecting buttons in a paled-out and blurred fashion in comparison with the active selecting buttons (see  FIGS. 2 and 5  through  7 ). 
     [3. Processing Sequence of External Diagnostic Apparatus  14 ] 
       FIGS. 3 and 4  are first and second flowcharts, respectively, of a processing sequence of the external diagnostic apparatus  14 . Prior to the processing sequence shown in  FIGS. 3 and 4 , the user (technician) turns on the PC  42 . For making a health diagnosis (deterioration diagnosis), the user turns on the IGSW  22  of the vehicle  12  to connect the ECU  20  and the tester  40  to each other for communication with each other and to connect the tester  40  and the PC  42  to each other for communication with each other. As described later, before step S 4  ( FIG. 3 ) at the latest, the user turns on the IGSW  22  to energize a starter motor, not shown, thereby to start the engine  26 . 
     In step S 1 , the PC  42  (function selecting function  120 ) judges whether a communication link has been established between the PC  42  and the vehicle  12  through the tester  40  or not. If a communication link has not been established (S 1 : NO), then control repeats step S 1 . 
     If a communication link has not been established at the time of step S 1 , then the PC  42  (function selecting function  120 ) may display, on the display unit  100 , the function selecting screen  200  with only the data view button  210  among the five diagnosis function selecting buttons being active (see  FIG. 5 ). In this case, the other selecting buttons (i.e., the data list button  212 , the DTC button  214 , the drive recorder button  216 , and the deterioration diagnosis button  218 ) are displayed as being inactive. Only the data viewing function  110  is allowed to be performed until a communication link with the vehicle  12  is established. 
     In  FIG. 5 , broken lines representing the selecting buttons  212 ,  214 ,  216 ,  218  indicate that these buttons are displayed in a paled-out and blurred fashion. Therefore, when the user sees how the selecting buttons are displayed, the user can recognize if each of the selecting buttons is active or inactive. 
     If a communication link with the vehicle  12  has been established (S 1 : YES), then the PC  42  (function selecting function  120 ) requests the user to enter vehicle information in step S 2 . Specifically, the PC  42  (function selecting function  120 ) displays an input box  220  on the display unit  100  as shown in  FIG. 6 . 
     In step S 3 , the PC  42  (function selecting function  120 ) judges whether vehicle information has been entered or not. Specifically, the PC  42  (function selecting function  120 ) judges whether vehicle information has been entered in the input box  220  and an OK button  222  has been pressed or not. If vehicle information has not been entered (S 3 : NO), then control repeats step S 3 . 
     If the user enters input data representing the user&#39;s intention to hold entering of vehicle information at the time of step S 3 , or more specifically, if the user selects a button  224  with “ENTER LATER” displayed thereon (hereinafter referred to as “hold button  224 ”) in the input box  220  shown in  FIG. 6 , then the PC  42  (function selecting function  120 ) may display, on the display unit  100 , the function selecting screen  200  with the selecting buttons other than the deterioration diagnosis button  218 , among the five diagnosis function selecting buttons (i.e., the data view button  210 , the data list button  212 , the DTC button  214 , and the drive recorder button  216 ) being active. In this case, until vehicle information is entered, the health diagnosis (deterioration diagnosis) is not permitted to be performed, but the other functions are permitted to be performed. 
     If the OK button  222  is pressed while required vehicle information is not entered in part or entirety, then an error message may be displayed and thereafter the input box  220  may be displayed again. 
     If vehicle information has been entered (S 3 : YES), then the PC  42  (function selecting function  120 ) acquires the engine rotational speed Ne [rpm] and the coolant water temperature Tw [° C.] of the engine  26  from the ECU  20  through the tester  40  in step S 4 . Specifically, the PC  42  (function selecting function  120 ) sends an output command for the engine rotational speed Ne and the coolant water temperature Tw to the ECU  20  through the tester  40 . In response to the output command, the ECU  20  acquires detected values from the engine rotational speed sensor  36  and the water temperature sensor  38  of the various sensors  24 , and sends the detected values to the PC  42  through the tester  40 . 
     In step S 5 , the PC  42  (function selecting function  120 ) judges whether the deterioration diagnosis function  118  can be performed or not. Specifically, the PC  42  judges whether or not the engine rotational speed Ne acquired in step S 4  is equal to or greater than a first engine rotational speed threshold value THne1 (hereinafter referred to as “threshold value THne1”) and equal to or smaller than a second engine rotational speed threshold value THne2 (hereinafter referred to as “threshold value THne2”). The threshold values THne1, THne2 define a range of engine rotational speed Ne at which the engine  26  operates in an idling state after it has been warmed up, and are stored in the storage unit  98  in advance. In addition, the PC  42  judges whether or not the coolant water temperature Tw acquired in step S 4  is equal to or greater than a water temperature threshold value THtw (hereinafter referred to as “threshold value THtw”). The threshold value THtw refers to a coolant water temperature Tw of the coolant water after the engine  26  has been warmed up, and is stored in the storage unit  98  in advance. 
     If the deterioration diagnosis function  118  can be performed (step S 5 : YES), then the PC  42  (function selecting function  120 ) displays the function selecting screen  200  with all the five diagnosis function selecting buttons  210 ,  212 ,  214 ,  216 ,  218 , which include the deterioration diagnosis button  218 , being active (see  FIG. 2 ) in step S 6 . 
     If the deterioration diagnosis function  118  cannot be performed (step S 5 : NO), then the PC  42  (function selecting function  120 ) displays the function selecting screen  200  with the deterioration diagnosis button  218  being inactive and the other selecting buttons  210 ,  212 ,  214 ,  216  being active (see  FIG. 7 ) in step S 7 . Then, in step S 8 , the PC  42  (function selecting function  120 ) displays an animation image  230  (hereinafter referred to as “image  230 ”) of the engine rotational speed Ne, an animation image  232  (hereinafter referred to as “image  232 ”) of the coolant water temperature Tw, and a message  234  that it takes time until the deterioration diagnosis can be performed, within the area of the deterioration diagnosis button  218  on the function selecting screen  200  (see  FIG. 7 ). 
     The image  230  is an animation image of a tachometer with its needle  236  displaced based on the engine rotational speed Ne acquired from the ECU  20 . The image  230  allows the user to recognize the present engine rotational speed Ne. The image  230  may include the range between the threshold value THne1 and the threshold value THne2, so that the user can visually recognize the target range of engine rotational speed Ne. 
     The image  232  is an animation image of a glass thermometer using a temperature-sensitive liquid with its level displaced based on the coolant water temperature Tw acquired from the ECU  20 . The image  232  allows the user to recognize the present coolant water temperature Tw. The image  232  may include the threshold value THtw or a range up from the threshold value THtw, so that the user can visually recognize the target coolant water temperature Tw or the target range. 
     The message  234  specifically includes descriptions “WAIT FOR WHILE” and “WAIT UNTIL CONDITIONS FOR IDLING MEASUREMENT ARE SATISFIED”. 
     After step S 6  or step S 8 , the PC  42  (function selecting function  120 ) judges whether either one of the five selecting buttons  210 ,  212 ,  214 ,  216 ,  218  has been selected or not in step S 9 . If neither one of the five selecting buttons  210 ,  212 ,  214 ,  216 ,  218  has been selected (S 9 : NO), then control goes back to step S 4 . If either one of the five selecting buttons  210 ,  212 ,  214 ,  216 ,  218  has been selected (S 9 : YES), then control goes to step S 10  shown in  FIG. 4 . 
     While control is repeating the loop of steps S 4 , S 5 : NO, S 7 , S 8 , S 9 : NO shown in  FIG. 3 , the animation images  230 ,  232  are displayed. If the IGSW  22  is on, but the starter motor is not energized and hence the engine  26  is not started, then the animation image  230  indicates an engine rotational speed Ne=0 and the animation image  232  indicates a coolant water temperature Tw at the time. If the engine  26  has been started, the animation images  230 ,  232  change gradually with time. 
     In step S 10  in  FIG. 4 , the PC  42  (function selecting function  120 ) judges whether the selected button is the deterioration diagnosis button  218  or not. If the selected button is not the deterioration diagnosis button  218  (S 10 : NO), then the PC  42  (function selecting function  120 ) performs the function corresponding to the selected button in step S 11 . For example, if the selected button is the DTC button  214 , then the PC  42  (function selecting function  120 ) performs the DTC function  114  corresponding to the DTC button  214  to read DTC data recorded in the ECU  20 , and the PC  42  (DTC function  114 ) displays, for example, a screen  240  shown in  FIG. 8  (hereinafter referred to as “DTC and freeze data screen  240 ” or “DTC screen  240 ”) on the display unit  100 . 
       FIG. 8  shows by way of example the DTC and freeze data screen  240 . As shown in  FIG. 8 , the DTC and freeze data screen  240  includes an area  242  for displaying information about DTCs acquired from the ECU  20  that is currently communicating with the PC  42 , an area  244  for displaying information about DTCs stored in the vehicle DB  130  of the PC  42  with respect to the vehicle  12  to be diagnosed, and a clear button  246 . The areas  242 ,  244  include respective buttons  248   a ,  248   b  for displaying freeze data (hereinafter referred to as “freeze data display buttons  248   a ,  248   b ”). When the user selects the button  248   a  or  248   b  through the operating unit  94 , freeze data corresponding to the selected button  248   a  or  248   b  are displayed. The clear button  246  is a button for clearing the displayed information about DTCs. 
     Back to  FIG. 4 , if the deterioration diagnosis button  218  is selected (S 10 : YES), then the PC  42  performs the deterioration diagnosis function  118  in steps S 12  through S 20 . 
     Specifically, in step S 12 , the PC  42  (deterioration diagnosis function  118 ) displays an initial screen for identifying an item to be diagnosed (an output sensor value of the vehicle  12 ). As shown in  FIG. 9 , the initial screen comprises a screen with diagnostic target items to be diagnosed (names) being surrounded by respective frames on the screen (hereinafter referred to as “visual display screen  250 ”). As described later, while the deterioration diagnosis function  118  is being performed, the displayed screen can be switched, for example, between the visual display screen  250  and a list display screen  260  or the like (see  FIG. 10 ). 
       FIG. 9  shows by way of example the visual display screen  250  that is displayed. As shown in  FIG. 9 , the visual display screen  250  includes a plurality of images  252  of diagnostic target items surrounded by respective frames (hereinafter referred to as “framed images  252 ”). When the user single-clicks either one of the framed images  252  to simply select it through the operating unit  94 , the selected framed image  252  is displayed with a thick frame. In  FIG. 9 , the framed image  252  of the diagnostic target item “BATTERY VOLTAGE” is displayed with a thick frame. Another framed image  256  which corresponds to the simply selected framed image  252  is also displayed together with a numerical value of the diagnostic target item in a display area  254  beneath the visual display screen  250 . In  FIG. 9 , the framed image  256  of the diagnostic target item “BATTERY VOLTAGE” is displayed in the display area  254 . When the user double-clicks either one of the framed images  252  to select it through the operating unit  94 , a screen, not shown, representing details of the selected framed image  252  is displayed. 
     The visual display screen  250  includes a display switching button  258  for switching the visual display screen  250  to the list display screen  260 . 
       FIG. 10  shows by way of example the list display screen  260 . The list display screen  260  has a list display field  262  (hereinafter referred to as “display field  262 ”) for displaying a list of details of system names, item names, detected sensor values, units, DTC codes, and DTC details of the respective diagnostic target items. When the user single-clicks a line corresponding to a diagnostic target item in the display field  262  to simply select the diagnostic target item through the operating unit  94 , the color of the line is changed, i.e., reversed, in display. When the user double-clicks either line to select the corresponding diagnostic target item through the operating unit  94 , a screen, not shown, representing details of the diagnostic target item corresponding to the line is displayed. 
     The list display screen  260  includes a display switching button  264  for switching the list display screen  260  to the visual display screen  250 . 
     Returning to  FIG. 4 , in step S 13 , the PC  42  (deterioration diagnosis function  118 ) judges whether a diagnostic target item has been selected or not. Specifically, the PC  42  judges that a diagnostic target item has been selected if either one of the framed images  252  on the visual display screen  250  has been single-clicked or double-clicked, for example. Alternatively, the PC  42  judges that a diagnostic target item has been selected if either one of the lines in the list display field  262  on the list display screen  260  has been single-clicked or double-clicked. 
     As described above, diagnostic target items that can be diagnosed in the present embodiment may include an engine rotational speed Ne, a water temperature sensor voltage, a throttle sensor voltage, an intake gas temperature sensor voltage, an intake pressure sensor voltage, an atmospheric pressure sensor voltage, an amount of injected fuel, an ignition timing, an idling air control valve opening degree, a battery voltage, and an oil temperature sensor voltage. 
     If no diagnostic target item has been selected (S 13 : NO), then the PC  42  (deterioration diagnosis function  118 ) judges whether the displayed screen is to be switched or not in step S 14 . Specifically, if the visual display screen  250  is being displayed, then the PC  42  judges whether the display switching button  258  has been selected or not, and if the list display screen  260  is being displayed, then the PC  42  judges whether the display switching button  264  has been selected or not. 
     If the displayed screen is to be switched (S 14 : YES), then the PC  42  (deterioration diagnosis function  118 ) switches the displayed screen in step S 15 . Specifically, if the visual display screen  250  is being displayed, then the visual display screen  250  is switched to the list display screen  260 . If the list display screen  260  is being displayed, then the list display screen  260  is switched to the visual display screen  250 . If the displayed screen is not to be switched (S 14 : NO) or after step S 15 , control goes back to step S 13 . 
     If a diagnostic target item has been selected in step S 13  (S 13 : YES), then the PC  42  (deterioration diagnosis function  118 ) acquires data (hereinafter referred to as “target data”) for diagnosing the selected diagnostic target item from the ECU  20  in step S 16 . Specifically, the PC (deterioration diagnosis function  118 ) sends an output command for the target data to the ECU  20  through the tester  40 . In response to the output command, the ECU  20  acquires the target data from the various sensors  24 , and sends the acquired target data to the PC  42  through the tester  40 . 
     In step S 17 , the PC  42  (deterioration diagnosis function  118 ) compares the acquired target data with a deterioration judgment threshold value. The deterioration judgment threshold value, which is established for each target data, is a threshold value for judging a deteriorated state of the target item. The deterioration judgment threshold value is established for each diagnostic target item as either one of upper and lower limit values. 
     In step S 18 , the PC  42  (deterioration diagnosis function  118 ) displays the result of the comparison between the target data and the deterioration judgment threshold value on the display unit  100 . 
     In step S 19 , the PC  42  (deterioration diagnosis function  118 ) judges whether another deterioration diagnosis is to be initiated or not. Specifically, a screen, not shown, for displaying the result of the comparison includes a button for initiating another deterioration diagnosis, and the PC  42  judges whether such a button has been selected or not. If the PC  42  judges that another deterioration diagnosis is to be initiated (S 19 : YES), then control goes back to step S 12 . If the PC  42  judges that another deterioration diagnosis is not to be initiated (S 19 : NO), then control goes to step S 20 . 
     In step S 20 , the PC  42  (deterioration diagnosis function  118 ) judges whether control is to return to the function selecting screen  200  ( FIG. 2 ) or not. Specifically, the screen, not shown, for displaying the result of the comparison includes a button for returning to the function selecting screen  200 , and the PC  42  judges whether such a button has been selected or not. If the PC  42  judges that control is not to return to the function selecting screen  200  (S 20 : NO), then control goes back to step S 18 . If the PC  42  judges that control is to return to the function selecting screen  200  (S 20 : YES), then control goes back to step S 4  shown in  FIG. 3 . 
     [4. Advantages of the Present Embodiment] 
     According to the present embodiment, as described above, since a deterioration diagnosis (health diagnosis) using detected sensor values is inhibited until the vehicle  12  has been warmed up, the deterioration diagnosis can be performed accurately. 
     While a deterioration diagnosis is being inhibited, the varying states of the engine rotational speed Ne and the coolant water temperature Tw that are used to judge a condition for inhibiting the deterioration diagnosis are displayed ( FIG. 7 ). Therefore, the user can confirm the reason why the deterioration diagnosis is inhibited, as the varying states in the engine rotational speed Ne and the coolant water temperature Tw, and can visually confirm the changing situation and how it changes until the inhibition of the deterioration diagnosis is canceled. In addition, in a case where it is taking more time than usual until the inhibition of the deterioration diagnosis is canceled, the user can recognize which one of the engine rotational speed Ne and the coolant water temperature Tw does not satisfy a condition for canceling the inhibition of the deterioration diagnosis. Therefore, the user is enabled to know that some trouble has been occurring in relation to the engine rotational speed Ne or the coolant water temperature Tw that does not satisfy the condition for canceling the inhibition of the deterioration diagnosis. 
     According to the present embodiment, it is checked whether the detected sensor values fall within normal ranges or not only when the vehicle  12  is idling (S 5  in  FIG. 3 : YES). Therefore, a deterioration diagnosis can be performed under a condition where the engine  26  is operating stably, and thus the deterioration diagnosis can be performed with high accuracy. 
     According to the present embodiment, the deterioration diagnosis button  218  for instructing the PC  42  (deterioration diagnosis function  118 ) to start a deterioration diagnosis is displayed on the function selecting screen  200  while the vehicle  12  is being warmed up and after the vehicle  12  has been warmed up. While the vehicle is being warmed up, the deterioration diagnosis button  218  is displayed as inactive (S 7  in  FIG. 3 ), and after the vehicle  12  has been warmed up, the deterioration diagnosis button  218  is displayed as active (S 6 ). The varying states of the engine rotational speed Ne and the coolant water temperature Tw are displayed together with the deterioration diagnosis button  218  that is displayed as inactive (S 8 ). 
     Thus, the varying states of the engine rotational speed Ne and the coolant water temperature Tw are displayed together with the deterioration diagnosis button  218  that is displayed as inactive until the displayed deterioration diagnosis button  218  goes from inactive to active. Consequently, information about whether the deterioration diagnosis is inhibited or not is given to the user in a plain fashion. In addition, since the user is enabled to know the progress status of warming-up of the vehicle  12  based on the varying states of the engine rotational speed Ne and the coolant water temperature Tw, the user can avoid wrong operations during the waiting time. 
     According to the present embodiment, while the vehicle  12  is being warmed up, the varying states of the engine rotational speed Ne and the coolant water temperature Tw are displayed as animation images on the function selecting screen  200  ( FIG. 7 ). Thus, the user can easily confirm the varying states of the engine rotational speed Ne and the coolant water temperature Tw, and can effectively use the waiting time until the inhibition of the deterioration diagnosis is canceled. 
     According to the present embodiment, when the PC  42  is turned on, it acquires the engine rotational speed Ne and the coolant water temperature Tw regardless of whether the engine  26  has started or not. For example, if the engine  26  is turned off and the engine rotational speed Ne is zero, then the animation image  230  representing the engine rotational speed Ne=0 is displayed (S 8  in  FIG. 3 ). Owing thereto, the user is enabled to know that the engine  26  is not started. 
     According to the present embodiment, when the deterioration diagnosis button  218  is displayed as inactive, the other selecting buttons (i.e., the data view button  210 , the data list button  212 , the DTC button  214 , and the drive recorder button  216 ) are displayed as active on the function selecting screen  200  ( FIG. 7 ). 
     Therefore, it is possible to start another function even before the preparations for the deterioration diagnosis are completed. The waiting time until the warming-up of the vehicle  12  is completed can thus be used to perform another function. 
     B. Modifications: 
     The present invention is not limited to the above embodiment, but may employ various arrangements based on the disclosure of the present description. For example, the present invention may employ the following arrangements: 
     [1. Objects Incorporating the Invention] 
     In the above embodiment, the PC  42  is used in combination with the vehicle  12  as a motorcycle. However, the PC  42  may be used in combination with other apparatus that need a warming-up operation (e.g., mobile objects such as ships, aircrafts, or the like). 
     [2. Configuration of External Diagnostic Apparatus  14 ] 
     In the above embodiment, the external diagnostic apparatus  14  comprises the tester  40  and the PC  42 . However, it is not limited in this respect. For example, the PC  42  and the tester  40  may integrally be combined with each other if the tester  40  comprises a high-functionality portable terminal device such as a tablet computer, a smartphone, or the like. 
     In the above embodiment, the PC  42  communicates with the ECU  20  via the tester  40 . However, it is not limited to such a configuration. The PC  42  and the ECU  20  may directly communicate with each other through a wireless or wired communication link. Alternatively, a laptop personal computer used as the PC  42  may be arranged to perform the functions of the tester  40 . 
     In the above embodiment, the diagnostic software used by the tester  40  is stored in advance in the storage unit  72  of the tester  40 . However, it is not limited to such a configuration. The diagnostic software may be downloaded from the PC  42  or an external source (e.g., an external server accessible through a public network), or may be executed by an ASP (Application Service Provider) without the need for downloading. The diagnostic software used by the PC  42  is stored in advance in the storage unit  98  of the PC  42 . However, it is not limited to such a configuration. The diagnostic software may be downloaded from an external source (e.g., an external server), or may be executed by an ASP. 
     [3. Function Selection and Function Selecting Screen  200 ] 
     In the above embodiment, the diagnosis function selecting buttons (i.e., the data view button  210 , the data list button  212 , the DTC button  214 , the drive recorder button  216 , and the deterioration diagnosis button  218 ) that correspond to the respective functions (i.e., the data viewing function  110 , the data list function  112 , the DTC and freeze data function  114 , the drive recorder function  116 , and the deterioration diagnosis function  118 ) are displayed. However, insofar as the deterioration diagnosis button  218  corresponding to the deterioration diagnosis function  118  is displayed, the display configuration is not limited to the above-mentioned one. For example, only the deterioration diagnosis button  218  may be displayed, but none of the data view button  210 , the data list button  212 , the DTC button  214 , and the drive recorder button  216  may be displayed. Alternatively, either one of the data view button  210 , the data list button  212 , the DTC button  214 , and the drive recorder button  216  may not be displayed. Further alternatively, another selecting button may be displayed in addition to the data view button  210 , the data list button  212 , the DTC button  214 , and the drive recorder button  216  or instead of either one of the data view button  210 , the data list button  212 , the DTC button  214 , and the drive recorder button  216 . 
     [4. Deterioration Diagnosis Function  118  and Deterioration Diagnosis Button  218 ] 
     In the above embodiment, the engine rotational speed Ne and the coolant water temperature Tw are used as detected sensor values used to judge whether the deterioration diagnosis function  118  can be performed or not (i.e., the status of warming-up) (S 5  in  FIG. 3 ). However, the detected sensor values are not limited to the above values insofar as they can be used to judge whether the deterioration diagnosis function  118  can be performed or not. For example, only one of the engine rotational speed Ne and the coolant water temperature Tw may be used. Alternatively, a gearshift position may be used in addition to, or instead of either one of, the engine rotational speed Ne and the coolant water temperature Tw. For example, the deterioration diagnosis function  118  may be judged as performable only when the gearshift position is “P” (parking) or “N” (neutral). Alternatively, the operating state of a foot brake or a parking brake may be used in addition to them or instead of either one of them. For example, the deterioration diagnosis function  118  may be judged as performable only when the foot brake or the parking brake is operated. 
     In the above embodiment, the vehicle  12  is confirmed as idling (S 5 ) before a selecting button is selected (S 9 ). However, the timing at which the vehicle  12  is confirmed as idling is not limited to the above timing. For example, the vehicle  12  may be confirmed as idling after the deterioration diagnosis button  218  has been selected (S 10  in  FIG. 4 : YES) and until the target data are acquired (S 16 ), and the deterioration diagnosis may be stopped if the vehicle  12  is not idling. 
     In the above embodiment, while the vehicle  12  is being warmed up, the deterioration diagnosis button  218  is displayed as inactive, and after the vehicle  12  has been warmed up, the deterioration diagnosis button  218  is displayed as active. However, a configuration without such a distinction between inactive display and active display may be provided.