Patent Publication Number: US-2010125388-A1

Title: Information writing tool and system

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application is based on and claims the benefit of priority of Japanese Patent Application No. 2008-294493, filed on Nov. 18, 2008, the disclosure of which is incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present disclosure generally relates to a vehicle information writing system, which employs a vehicle information writing tool. 
     BACKGROUND INFORMATION 
     Japanese patent documents Laid-Open No. 2003-337748 (US publication of No. 20030221049), No. 2003-172199, and No. 2001-229014 are referenced in the following description. 
     In recent years, vehicles use electric control units, a so-called ECU, for controlling various devices and equipments disposed therein. The ECUs are disposed in the vehicle, and perform various processes for controlling devices and equipments in the vehicle, based on software executed by a microprocessor in respective ECUs. The software in the ECUs is updated at times, for accommodating version-ups, bug-correction, and the like. Therefore, the software in the ECUs is stored in a non-volatile memory such as a flash memory or the like. Refer to the three patent documents listed above, for example. Further, for accommodating various process contents depending on the vehicle types and vehicle specifications, vehicle information representing each of those vehicle types and vehicle specifications is also stored in the non-volatile memory for reference purposes. The software refers to the vehicle information in the non-volatile memory for realizing a vehicle specification that is specific for each of the various destination areas and/or countries. That is, vehicle information is changed for country to country, area to area, for accommodation of various vehicle types and for conformity to regulations in the destination countries. For example, for the vehicles used in cold districts, cold districts specification is arranged, and the vehicle information for use in the cold districts vehicle reflects the cold districts specification. 
     The ECU as a part of the vehicle components is replaced with a new one, when the ECU is diagnosed to be suffering from irreparable trouble. That is, for example, after the vehicle is brought to a dealer and is diagnosed to be broken, the ECU is replaced with a new one (i.e., a supplemental ECU) when the trouble of the relevant function is identified as caused by the ECU by checking the vehicle maintenance history or the like. 
     When the ECU is replaced with a new one, a mechanic in the dealer checks a part number of the supplemental ECU based on the vehicle type/specification, places an order of the supplemental ECU, and then actually replaces the ECU after receiving the ECU. Therefore, in the course of ECU replacement, a vehicle maker prepares a part number list that covers all of the vehicle types and specifications, a part supplier supplies supplemental ECUs respectively having vehicle information that is designed to cover each of all the vehicle types and specifications in the list based on inventory, and the dealer receives a specific ECU by placing an order based on the part number list. 
     However, when replacing the ECU with a new one, a mistake of the software portion of the ECU is hard to be identified, in comparison to a mistake of the hardware portion. That is, the mistake of the software portion, such as a misplacement of the software or the like, can only be found after mounting the ECU on a vehicle and conducting a detailed test. Therefore, when the part number of the ECU is mis-ordered or the ECU has different vehicle information written therein, the replaced ECU may cause malfunction of the vehicle or un-conformity of the vehicle to the regulation of the destination country. Further, the part number management of the ECU is a burden for the part supplier and the vehicle maker, due to a huge number of specifications, vehicle types and destination countries. 
     SUMMARY OF THE INVENTION 
     In view of the above and other problems, the present disclosure discloses a vehicle information writing tool and a vehicle information writing system that appropriately handle a number of different supplemental ECUs, especially for preventing mis-replacement of an ECU and/or mis-writing of vehicle information on an ECU. 
     In an aspect of the present invention, the vehicle information writing tool used in connection to a vehicle connector of a vehicle side control unit is disclosed. The information writing tool basically includes (i) a main controller with two components of (a) a vehicle memory that stores vehicle information in a non-volatile memory unit and (b) a microprocessor that performs, by referring to the vehicle information, a control process for controlling a vehicular electric device in a vehicle, (ii) the vehicle connector that detachably connects the information writing tool for writing the vehicle information in the vehicle memory, and (iii) a memory writing unit that writes the vehicle information transferred from the information writing tool to the vehicle memory. Further, the information writing tool includes: a tool memory for storing the vehicle information; a tool connector for detachably connecting the vehicle connector to transfer the vehicle information to the vehicle memory; an attachment detector for detecting the attachment of the tool connector to the vehicle connector; and an information transfer control unit for starting a transfer process of the vehicle information from the tool memory to the vehicle memory. Further, the vehicle information representative of one vehicle type has variations respectively corresponding to different vehicle specifications of multiple shipping destinations, and the tool memory stores a portion of the variations of the vehicle information of one vehicle type corresponding to the vehicle specifications of one shipping destination. 
     In addition, the vehicle information writing system of the present disclosure includes: multiple pieces of the information writing tool of described above for storing the vehicle information respectively corresponding to the different shipping destinations; and the vehicle side control unit for providing (i) the main controller with two components of (a) the vehicle memory that stores the vehicle information specific to each vehicle specification in the non-volatile memory unit and (b) the microprocessor that performs, by referring to the vehicle information, a control process for controlling a vehicular electric device in the vehicle, (ii) the vehicle connector that exclusively allows connection of some of the multiple information writing tools corresponding to intended vehicle specifications via the tool connector disposed thereon, and (iii) the memory writing unit that writes the vehicle information transferred from the information writing tool to the vehicle memory. 
     According to the vehicle information writing tool/system of the present disclosure, the electric control unit (ECU), which is going to be replaced or repaired, has the vehicle connector, and the ECU is paired with the vehicle information writing tool that has the tool connector having a one-to-one relation to a corresponding vehicle specification. As described above, contents of the vehicle specification in the vehicle side control unit (i.e., the ECU) vary depending on the vehicle type, and even in the same vehicle type, there are variations of specifications depending on the various shipping destinations. Therefore, the vehicle information writing tool exclusively stores, in its non-volatile memory, the specific vehicle information corresponding to one of the various shipping destinations. Thus, the vehicle information writing tool having the tool connector is connected to the vehicle connector, and the vehicle information in the writing tool is retrieved from the memory to be written to the vehicle memory in the ECU, when attachment of the tool connector to the vehicle connector is detected. 
     The following advantageous effects are achieved in the above operation scheme. That is: 
     (1) The vehicle information specific to each vehicle is transferred from the tool to the vehicle side control unit for writing information, thereby enabling an inventory control free ECU delivery scheme, due to the on-demand information transfer and writing to the ECU at the time of replacement/repair. This operation scheme reduces the inventory control of various kinds of ECUs, which are otherwise required for the preparation and storage of different ECUs for respective shipping destinations and various vehicle types. 
     (2) When the vehicle side control unit installed in the vehicle is replaced with the supplemental control unit that does not yet have the vehicle information written in the vehicle memory, the vehicle information is legitimately written in the memory by selecting the writing tool that corresponds to the intended vehicle specification and by connecting the tool side connector to the vehicle side connector. That is, in other words, the writing tool is prepared for each of the multiple specifications of the same (single) shipping destination of the same (single) vehicle type. The writing tools are then distributed to the dealers in each of the multiple destinations with the vehicle information specific to each of those destinations stored in the tools. Then, the supplemental control unit without the vehicle information written therein can be used for replacing the broken unit, thereby greatly reducing the inventory control efforts by the parts supplier. After the replacement of the hardware (i.e., the control unit), the vehicle information is written from the tool to the control unit, by connecting the tool to the supplemental unit. Therefore, the vehicle side control unit is appropriately performed at the dealer. More practically, the shipping destination specific vehicle information can be securely delivered to the dealers in respective shipping destinations without confusion of different destination information, only by devising destination specific writing tool preparation scheme. In other words, the vehicle information for wrong shipping destination is securely prevented from being written into the control unit at the repair shop in the dealers. 
     The non-volatile tool memory is configured to store the vehicle information that corresponds to only one vehicle specification from among various types of specifications of a single vehicle type designed to be one shipping destination. Therefore, the writing tool can be prepared in one-to-one correspondence manner to respective vehicle specifications. That is, in other words, the intended vehicle information can be written in the vehicle memory by selecting the writing tool that corresponds to the intended vehicle information. Thus, the mis-writing of the vehicle information to the vehicle memory can be securely prevented. 
     Further, the vehicle side control unit can be used as the information writing tool, in consideration of the compatibility of their components. That is, the vehicle memory in the vehicle side control unit can serve as the tool memory in the information writing tool, and the main controller in the vehicle side control unit can serve as the tool memory in the information writing tool, provided that the vehicle side control unit includes (i) the main controller with two components of (a) the vehicle memory that stores vehicle information in a non-volatile memory unit and (b) the microprocessor that performs, by referring to the vehicle information, a control process for controlling a vehicular electric device in a vehicle, (ii) the vehicle connector of the vehicle side control unit is connected to the tool connector of the information writing tool that stores the vehicle information of a corresponding vehicle specification, and (iii) the memory writing unit that writes the vehicle information transferred from the information writing tool to the vehicle memory. In addition, the vehicle side control unit additionally has (a) the tool connector that detachably connects the vehicle connector on another vehicle side control unit for transferring the vehicle information to the vehicle memory of the another vehicle side control unit, and (b) the attachment detector for detecting the attachment of the vehicle connector to the tool connector. That is, in other words, the vehicle side control unit is formed as the control unit having the writing tool function attached thereto, by the addition of the above two components, that is, the tool connector and the attachment detector. More practically, the tool memory and the information transfer control unit in the writing tool is readily provided as the vehicle memory and the main controller in the vehicle side control unit, and the vehicle memory stores the relevant vehicle information that is used to execute a vehicular device control process. Therefore, the vehicle side control unit can practically serve as the information writing tool by adding the tool side connector and the attachment detector and by using the main controller as the information transfer control unit. Therefore, the information writing tool does not have to be designed and developed from scratch, by only reserving one of the vehicle side control unit as the information writing tool. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Objects, features, and advantages of the present disclosure will become more apparent from the following detailed description made with reference to the accompanying drawings, in which: 
         FIG. 1  is a front/top/back view of a vehicle information writing tool of the present disclosure; 
         FIG. 2  is an exploded view of a modification of the vehicle information writing tool of the present disclosure; 
         FIG. 3  is an exploded view of another modification of the vehicle information writing tool of the present disclosure; 
         FIG. 4  is an illustration of combination of the vehicle information writing tools; 
         FIG. 5  is an illustration of an outline operation scheme of a vehicle information writing system; 
         FIG. 6  is an illustration of communication conditions displayed on a display unit of a connector; 
         FIG. 7  is a block diagram of the vehicle information writing tool in an exemplary configuration; 
         FIG. 8  is a block diagram of a vehicle side control unit in an exemplary configuration; 
         FIG. 9  is a flowchart of a detailed operation scheme of the vehicle information writing system; 
         FIG. 10  is a flowchart of another detailed operation scheme of the vehicle information writing system; 
         FIG. 11  is a block diagram of the vehicle information writing tools in another exemplary configuration; 
         FIG. 12  is a block diagram of a vehicle side control unit having the vehicle information wiring tool in an exemplary configuration; and 
         FIG. 13  is a block diagram of an example of an ID set unit of the vehicle side control unit. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present disclosure are described with reference to the drawings in the following. 
       FIG. 1  is an external view of an example of a vehicle information writing tool of the present disclosure.  FIG. 7  is a block diagram of the vehicle information writing tool showing an exemplary configuration of its electric components.  FIG. 8  is a block diagram of a vehicle side control unit (i.e., an ECU) in an exemplary configuration. The ECU, or a vehicle side control unit  100  in  FIG. 8 , is connected to a vehicle information writing tool  1  shown in  FIG. 7 . 
     The vehicle side control unit  100  in  FIG. 8  has a vehicle side nonvolatile memory  311  for storing vehicle information that is specific to each of the various vehicle specifications, a main controller  310  having a microprocessor for executing control processes of vehicular electric devices by referring to the vehicle information, and a vehicle side connector  110  that detachably connects the vehicle information writing tool  1  when vehicle information is written in the vehicle side nonvolatile memory  311 . The main controller  310  serves as a memory writing unit for writing the vehicle information in the vehicle side nonvolatile memory  311  when the vehicle information is transferred from the writing tool  1  through the connector  110 . 
     As shown in  FIG. 7 , the writing tool  1  is configured as an information writing tool  1  that is used in a connected condition to the vehicle side connector  110 . More practically, the writing tool  1  has (i) a tool side nonvolatile memory  211  that stores the vehicle information specific to only one shipping destination from among various versions of vehicle information respectively prepared for each of the specifications corresponding to the different shipping destinations of a certain vehicle type, (ii) a tool side connector  11  that detachably connects the vehicle side connector  110  for the transfer of the vehicle information to the vehicle side nonvolatile memory  311 , (iii) a connection detection switch SW 4  that is, as a connector attachment detection unit, switched for detecting attachment of the vehicle side connector  110  to the tool side connector  11  when the tool side connector  11  is attached to the vehicle side connector  110 , and (iv) an information transfer control unit  210  for starting a transfer process of written information in the tool side nonvolatile memory  211  to the vehicle side nonvolatile memory  311  upon detecting the attachment of the tool side connector  11  to the vehicle side connector  110 . The tool side nonvolatile memory  211  and the information transfer control unit  210  are implemented on a circuit board  20 . As shown in  FIG. 1 , the writing tool  1  has a tool housing  2  that houses the above circuit board  20 , and the tool side connector  11  connected to the circuit board  20  is integrally disposed on an outer face of the tool housing  2   
     As for the information transfer control unit  210  of the vehicle information writing tool  1 , the electric power is supplied from the vehicle side through the tool side connector  11  and the vehicle side connector  110 . That is, as shown in  FIG. 8 , the vehicle side control unit  100  has a power supply circuit  314  for supplying an electric power caused by a battery voltage of a vehicle battery to a power terminal of the vehicle side connector  110 . 
     In addition, as shown in  FIG. 7 , the vehicle information writing tool  1  has a tool side communication circuit  212  to be connected to the tool side connector  11 . The information transfer control unit  210  transfers the vehicle information to the vehicle side control unit  100  through the tool side communication circuit  212 . Further, as shown in  FIG. 8 , a vehicle side communication circuit  312  to be connected to the vehicle side connector  110  is disposed on the vehicle side control unit  100 , enabling the vehicle information received by the vehicle side communication circuit  312  to be written in the vehicle side nonvolatile memory  311 . 
     In  FIG. 7 , the above-mentioned tool side nonvolatile memory  211  and the tool side communication circuit  212  are connected to the information transfer control unit  210  of the vehicle information writing tool  1 . The tool side nonvolatile memory  211  may be implemented as a read-only memory (ROM) if the contents of the vehicle information are not changed, for example. On the other hand, if the contents of the vehicle information are changed, the memory  211  may be implemented as an EEPROM, a flash memory or the like. The tool side communication circuit  212  is implemented as an interface IC of a vehicular communication bus (e.g., as a CAN bus or a LIN bus), and is connected to a tool communication terminal  202 . Though the tool communication terminal  202  is simplified in  FIG. 7 , the terminal  202  has multiple pins disposed thereon for compliance to the relevant communication standard. 
     The above-described components, that is, the information transfer control unit  210 , the tool side nonvolatile memory  211 , and the tool side communication circuit  212  respectively receives an electric power from a regulator IC  220  that serves as a power circuit implemented on the circuit board  20 . The input of the regulator IC  220  is connected to a tool power supply terminal  201  through the above-mentioned detection switch SW 4  and a noise filter  221 . Further, the ground of each of the circuit elements is unified to be connected to a ground terminal  203  of the tool  1  as shown in  FIG. 7 . 
     As already described with reference to  FIG. 1 , the tool side connector  11  has, in a cylindrical socket  5  disposed on one side of the housing  2  having a rectangular parallelepiped shape, a power terminal pin  11   p , a ground terminal pint  11   g , and multiple communication terminal pins  11   c . The power terminal pin  11   p  is connected to the tool power supply terminal  201 , the ground terminal pin  11   g  is connected to the tool ground terminal  203 , and the multiple communication terminal pins  11   c  are connected to the tool communication terminal  202 . Further, a switch portion of the connection detection switch SW 4  is disposed on an outer face of the housing  2  in a protruding manner, for detecting the connection of the tool side connector  11  on the vehicle side connector  110 . That is, when the switch portion of the connection detection switch SW 4  is pressed by the vehicle side connector  110 , the connection detection switch SW 4  is turned on. On the other hand, when the tool side connector  11  is pulled out from the vehicle side connector  110 , a pressing force applied to the switch portion of the connection detection switch SW 4  is released, thereby turning off the connection detection switch SW 4 . 
     The vehicle information writing tool  1  has a communication condition indicator  222  for displaying a communication condition with the vehicle side control unit  100  as shown in  FIG. 7 . That is, the indicator  222  changes its color, for example, according to the communication condition. The indicator  222  is controlled by communication condition information from the vehicle side communication circuit  312  in  FIG. 8 . The communication condition information is received by the tool side communication circuit  212 , and the contents of the communication condition information are reflected to a display condition of the indicator  222  under control of the information transfer control unit  210 . That is, for example, the color of the indicator  222  is changed according to the communication condition information. 
     The communication condition indicator  222  is, in the present embodiment, formed by using light emitting diodes (LEDs), which can change their color, for the purpose of indicating the communication conditions in different colors. As shown in  FIG. 1 , the tool hosing  2  has a transparent portion  3 , and the transparent portion  3  lets the light from the LED of the indicator  222  go therethrough. The transparent portion  3  has a marking  3 D that specifies a vehicle type and/or a shipping destination handled by the vehicle information writing tool  1  represented by text as shown in  FIG. 1 . In the present embodiment, the text of the marking  3 D is formed by using a transparent material, with its surroundings formed by using non-transparent material, thereby making the text marking stand out from the surroundings in a color of the LED, which reflects the communication condition between the writing tool  1  and the vehicle side control unit  100 . The indicator  222  may be formed by using a dot-matrix display, a 7-segment LED display, or other type of displays. That is, as far as being capable of displaying the communication condition by using text, numerical figures, icons or the like, the indicator  222  may be formed by using any type of display device. 
       FIG. 2  is a modification of the connector  1 , in which an opening of the tool housing  2  is closed by the circuit board  20 . That is, the circuit board  20  serves as a cover wall of the opening of the tool housing  2 . The tool side connector  11  is formed as a protrusion from the outside of the board  20 . Further,  FIG. 3  shows another modification of the connector  1 . That is, a socket portion  5  of the connector  1  is integrally formed with the circuit board  20 , to be serving as a lid  2 B of an opening of the housing  2 . When the circuit board  20  is inserted into a body  2 A of the housing  2  from the opening, the lid  2 B is engaged with the body  2 A. 
     The vehicle side control unit  100  in  FIG. 8  has the vehicle side nonvolatile memory  311 , the vehicle side communication circuit  312 , a load drive circuit (i.e., a driver circuit of in-vehicle electronic devices under control of the ECU) and the switch read circuit  313  disposed on a circuit board  120  for connection to the main controller  310 . The above-mentioned vehicle information is memorized, together with control software of the in-vehicle electronic devices, in the vehicle side nonvolatile memory  311 , which is composed of an EEPROM, a flash memory, or a one-time ROM. The vehicle side communication circuit  312  is composed of the interface IC of the above-mentioned vehicular communication bus, as is the tool side communication circuit  212 , and is connected to a communication terminal  302  in the circuit board  120 . The output of the load drive circuit is connected to a load connection terminal  304 . 
     The switch read circuit  313  has a group of switches  364  connected thereto through a switch terminal  353 . The group of switches  364  serves as an ID setting unit. The group of switches  364  is formed as a group of DIP switches  364  in the present embodiment. The group of DIP switches  364  is used for setting a vehicle ID that is specific to a certain vehicle type and specification. That is, when one vehicle is shipped to a certain destination having a specification that is suitable to that destination, the vehicle side control unit has a certain vehicle ID that specifies that shipping destination and specification. Thus, the vehicle ID is used to determine that the vehicle information writing tool  1  matches with the designated shipping destination and specification of that vehicle. A diode  305  disposed on each of the inputs of the group of DIP switches  364  is used to prevent a leading-in current from the ground in case of alternation of input polarity of battery voltage +B due to superposition of alternator voltage as well as preventing the input terminals of the switch read circuit  313  from breakage by the static electricity. 
     The ID setting unit may have a different configuration from the above-described form that is realized by using the DIP switches. That is, as long as being capable of setting electrically-retrievable information that uniquely corresponds to a certain ID, any mechanism can be used. For example, by utilizing jumper terminal units J 1  to J 5  between voltage-dividing resistors Rj 1  to Rj 5  connected in a series to a signal voltage VCC as shown in  FIG. 13 , the divided voltage of adjacent voltage-dividing points can be distributed to be input to A/D conversion ports of the main controller  310  in a suitable manner for representing a certain ID based on a combination of jumper positions of jumpers JA to JD. In the present embodiment, each of the jumper terminal units J 1  to J 5  is configured to selectively set a jumper between two adjacent voltage-dividing points, thereby enabling to change the level of the analog input voltage by the amount of one voltage-dividing resistor, depending on the jumper position being on the ground side or the signal voltage VCC side. That is, in other words, the analog input voltage of the A/D conversion ports can be controlled to represent an ON (i.e., one) state and an OFF (i.e., zero) state of a certain digit, for ID coding. 
     The switch read circuit  313  reads the setting of the DIP switches  364 , and generates a vehicle side  1 D signal that is input to the main controller  310 . On the other hand, the tool side nonvolatile memory  211  of the writing tool  1  in  FIG. 7  stores a tool side ID that specifies the vehicle type and specification relevant to the vehicle information in the memory  211 . When the writing tool  1  is connected to the vehicle side control unit  100 , the tool side ID is transferred to the vehicle side control unit  100 , and the vehicle side control unit  100  examines the received tool side ID for determining whether the tool side ID matches the vehicle side ID. If the IDs match with each other, the vehicle side control unit  100  allows the writing tool  1  to transfer the vehicle information. If the IDs do not match, the transfer of the vehicle information is prohibited. The matching examination may be performed on the writing tool side, by transferring the vehicle side ID from the vehicle to the writing tool  1 . 
     The main controller  310 , the vehicle side nonvolatile memory  311 , the vehicle side communication circuit  312 , the switch read circuit  313 , and the load drive circuit, respectively receives a power voltage from the regulator ID  320  that serves as a power circuit on the circuit board  120 . The input of the regulator IC  320  is connected to a vehicle power supply terminal  351  that receives the battery voltage +B through a noise filter  321  by in-vehicle the pitcher and the catcher. The grounds (not shown in the drawing) of each of the circuit elements are unified, and are connected to a ground terminal  354  that leads to a ground line of a vehicle body. Further, on the vehicle side connector  110  of the circuit board  120 , a connector side power terminal  301 , a communication terminal  302  and connector side ground terminal  303  are formed, respectively for connection to a power terminal pin, a ground terminal pin and a communication terminal pin of the tool side connector  1  through said the vehicle side connector  110 . The connector side ground terminal  303  is connected to the ground terminal  354  through a ground conductor formed on the circuit board  120 . 
     The battery voltage +B input into the vehicle power supply terminal  351  is also distributed to the connector side power terminal  301  through the power supply circuit  314 . The power supply circuit  314  is a power switch circuit that switches between supply and shut-off of the battery voltage +B to be supplied to the connector side power terminal  301  in response to an instruction from the main controller  310 . On the other hand, to an IG terminal  352  of the circuit board  120 , an ignition switch signal from the vehicle side is input through a pull-down resistor  373  and an adjustment resistor  374 , toward the main controller  310 . The main controller  310  turns on the power supply circuit  314  when the ignition switch signal is input, for supplying the battery voltage +B to the connector side power terminal  301 . If the vehicle information writing tool  1  is connected to the vehicle side connector  110  when the circuit  314  is turned on, the battery voltage +B is supplied to the tool power supply terminal  201  of  FIG. 7  as the power voltage. Then, the connection detection switch SW 4  is turned on at the same time, the battery voltage +B is supplied to the information transfer control unit  210  through the regulator IC  220  the information transfer control unit  210 , for enabling the operation of the control unit  210  for information transfer to the vehicle side control unit  100 . On the other hand, when the ignition switch signal is not input, the power supply circuit  314  is turned off, and the battery voltage +B is not supplied to the connector side power terminal  301 . Thus, the vehicle information writing tool  1  is not operable even if it is connected to the vehicle side connector  110 . 
     Assuming that the vehicle side control unit  100  controls a lighting system of the vehicle, and that an auto lamp-off function for automatically turning off the head lamps and tail lamps (i.e., for preventing inadvertent lamp on at the time of parking) is either recommended or mandated, under the circumstance that “daytime running light” is mandated/recommended in North America (especially in Canada), the fact that, depending on the shipping destination, same type vehicles may have different vehicle information for different function/specification is apparent. Likewise, if the vehicle side control unit  100  controls security related functions or buzzer related function, the vehicle side control unit  100  must accommodate prohibition of an answer-back buzzer function in association with the smart-entry function in some destinations. Therefore, the vehicle information is different depending on the vehicle type and/or vehicle specification that customizes the same vehicle type to specific requirements of the shipping destination. 
     If the control unit  100  described above has an irreparable trouble, the control unit  100  has to be replaced with a new one. In that case, if the replaced control unit  100  is designed to be shipped to a different destination by mistake, the control unit  100  may allow a function that is prohibited in the shipping destination, or may not comply with the regulation of the shipping destination due to inoperability of the required function. 
     In the present disclosure, as shown in  FIG. 4 , the vehicle information writing tool  1  is prepared for every one of multiple specifications that are produced as a matrix of multiple vehicle types and multiple shipping destinations. That is, three shipping destinations including North America, Domestic, Europa are multiplied by the two vehicle types A and B to yield six different destination-vehicle type combinations, in which two or three different specifications are respectively arranged, thereby leading to a total of eleven vehicle information writing tools  1 , due to the one to one correspondence of the specifications and the writing tool  1 . Thus, each of the eleven different writing tools  1  stores respectively different vehicle information in the tool side nonvolatile memory  211  for realizing the intended vehicle specification. The dealers in the respective shipping destinations receive a set of writing tools  1  that include the required vehicle specifications for each of the vehicle types. 
     When the vehicle that has a broken vehicle side control unit  100  is brought to a dealer, the broken vehicle side control unit  100  causing a trouble is removed, and a supplemental vehicle side control unit that stores, in the vehicle side nonvolatile memory  311 , no written-in vehicle information that may differ depending on the shipping destinations for the same vehicle type is installed. Then, the vehicle information writing tool  1  corresponding to the relevant vehicle specification is connected to the vehicle side connector  110 , to write the vehicle information in the tool side nonvolatile memory  211  in the vehicle side nonvolatile memory  311  by transferring the information to the supplemental vehicle side control unit. As a result, the vehicle information for the different shipping destination or for the different specification is securely prevented to be written in the memory  311 . Further, the supplier of the supplemental vehicle side control units is not required to ship those units by writing the vehicle type/specification specific vehicle information in advance. Thus, the supplier is freed from hassles for preparing vehicle side control units for each of the different vehicle types and specifications, thereby dispense with the inventory control of different ECU products. 
     A systematic operation of writing the vehicle information involving the writing tool  1  and the control unit  100  is described with reference to a flowchart in  FIG. 9 . The illustration in  FIG. 5  shows an outline concept of vehicle information writing. In S 101 , the broken vehicle side control unit is replaced with a supplemental vehicle side control unit (i.e., an ECU), and, in S 102 , the tool side connector  11  of the vehicle information writing tool  1  is connected to the vehicle side connector  110  of the supplemental vehicle side control unit. Then, if an ignition switch signal is detected in S 103  (when an IG switch is turned on), a power supply is provided from the vehicle to the vehicle information writing tool  1  according to the above-mentioned procedure. When the vehicle information writing tool  1  detects the power supply, the writing tool  1  switches the communication condition indicator  222  from a non-lighted condition representing no-power supply to a lighted condition that is shown in  FIG. 6  at (a) portion. The color of the LED is, in this case, lighted in white. 
     Subsequently, the ID matching is performed in the above-described manner. If the writing tool is determined as not-matching, the writing process is concluded without information transfer and writing. On the other hand, when it is determined that the ID is matching and the writing tool is appropriate, the process proceeds to S 105  for transferring to the supplemental vehicle side control unit (i.e., an ECU) an inquiry signal that inquires if it is OK to start transferring the vehicle information. If, in S 106 , a response from the control unit that indicates that the transferring of the vehicle information is OK is received, the process proceeds to S 107  and the vehicle information stored in the tool side nonvolatile memory  211  is transferred to the vehicle side. The transferred information is received on the vehicle side, and the information is written in the nonvolatile memory  311  of the supplemental vehicle side control unit. When the transfer of the vehicle information is complete in S 108 , the process proceeds to S 109 , and the color of the communication condition indicator  222  is changed to a lighted condition that indicates a normal completion of information transfer (and writing), as shown in  FIG. 6  at (c) portion. That is, the LED color is changed to blue. On the other hand, when a response from the supplemental vehicle side control unit indicates that the start of information transfer is not OK in S 106 , or when the transferred vehicle information is not successfully written, the process proceeds to S 112 , and the communication condition indicator  222  is changed to a lighted condition that indicates the failure of the information transfer as shown in  FIG. 6  at (b) portion. That is, the LED color is changed to red. The communication condition indicator  222  is apparently changing its lighted condition according to the contents of information that reflects communication condition. That is, In other words, the color of the LED indicates the connector condition, or information transfer condition, thereby allowing a mechanic to confirm whether the vehicle information corresponding to a vehicle specification of a specific shipping destination of a certain vehicle type has been written to the ECU. 
     In either case, if the IG switch is turned off in S 116 , the power supply to the vehicle information writing tool  1  is shut off, and the communication condition indicator  222  is switched to the non-lighted condition representing no power supply. The user confirms this no power supply condition, for removing the vehicle information writing tool  1  from the vehicle side connector  110 . 
     Further, the vehicle information writing tool  1  may be operated without referring to an ignition switch signal. A flowchart in  FIG. 10  shows this process. In  FIG. 10 , like numbers represents like steps, and focus of the following description is put on the difference from  FIG. 9 . After connecting the writing tool  1  in S 102 , the power supply is provided from the vehicle side to the vehicle information writing tool  1  regardless of the condition of the ignition switch signal in S 1031 . In this case, the power supply circuit  314  in  FIG. 8  may be omitted and the battery voltage +B may be directly supplied to the connector side power terminal  301 . When the battery voltage +B is directly supplied to the terminal  301 , the writing tool  1  always has the power supply regardless of the signal condition. Therefore, the communication condition indicator  222  does not have the non-lighted condition indicative of no power supply. That is, in other words, the indicator  222  immediately turns on in the lighted condition in the color of white upon being connected to the vehicle side connector  110 . 
     In S 1032 , all doors of the vehicle are closed, and, in S 1033 , all doors of the vehicle are locked. Then, the process proceeds to S 1051  to send an inquiry signal from the writing tool  1  to the supplemental vehicle side control unit (i.e., an ECU), inquiring whether starting of transferring the vehicle information is OK. Then, in S 106  to S 109 , the same procedure is taken as  FIG. 9 . Then, in S 1011 , after confirming the LED color, the process proceeds to S 111  for disconnecting the writing tool  1  from the vehicle side connector  110  if the LED color of the indicator  222  is either blue (=successful transfer) or red (=transfer failure). If the condition of the indicator  222  corresponds none of the above two conditions, it is determined as communication failure, and the contents of the communication failure is determined after proceeding to S 1012 . 
     The indicator  222  may be configured to only represent a power voltage supply condition to the information transfer control unit  210  as shown in  FIG. 11 . In that case, the detection condition of the connection detection switch SW 4  is detected by the switch read circuit  213 , and the information transfer control unit  210  receives the detection signal from the read circuit  213  for controlling the lighted condition of the indicator  222 . In other words, because the indicator  222  is configured to receive the power supply through the tool power supply terminal  201 , the indicator  222  is not switched to the lighted condition without the supply of the battery voltage +B to the tool power supply terminal  201 , even when the connection detection switch SW 4  is turned on, 
       FIG. 12  shows an example of the function of the vehicle information writing tool added to the vehicle side control unit  100  of  FIG. 8  (i.e., a tool function added vehicle side control unit). In  FIG. 12 , the writing tool  1  of  FIG. 7  is incorporated to the control unit  100 . However, the writing tool  1  of  FIG. 11  may be incorporated to the control unit  100 . In  FIG. 12 , the reference numerals in parentheses show correspondence of the components in the control unit  100  to respective components in the writing tool  1  in  FIG. 7 . More practically, the microprocessor serving as the main controller  310  corresponds the information transfer control unit  210 , and the vehicle side nonvolatile memory  311  corresponds to the tool side nonvolatile memory  211 , and the vehicle side communication circuit  312  corresponds to the tool side communication circuit  212 , respectively. That is, in other words, the components  310 ,  311 ,  312  in the control unit  100  respectively provide, besides their original functions, the function of the components  210 ,  211 ,  212  of the writing unit  1  in a combined manner. Further, same as in  FIG. 7 , the communication condition indicator  222 , the tool power supply terminal  201 , the tool communication terminal  202 , the tool ground terminal  203 , and the tool side connector  11  are added to  FIG. 12 . The tool power supply terminal  201  is connected to the vehicle power supply terminal  351  on the circuit board  120 , and the connection detection switch SW 4  is added to the circuit between the terminal  201  and the switch SW 4 . Further, the tool ground terminal  203  is connected to the ground terminal  354 , and the tool communication terminal  202  is connected to the vehicle side communication circuit  312 , respectively. 
     The vehicle side nonvolatile memory  311  has a control program for controlling the vehicle information transfer and display of the communication condition indicator  222  added thereto. The main controller  310  executes the control program for transferring the vehicle information in the memory  311  to the supplemental vehicle side control unit according to the process described in  FIGS. 9 and 10  while the tool side connector  11  is connected to the vehicle side connector  110  of the supplemental vehicle side control unit. The vehicle information in the vehicle side nonvolatile memory  311  is used by the vehicle side control unit  100  in  FIG. 12  for controlling the vehicular electric devices. Therefore, the vehicle information in the nonvolatile memory  311  specifies only the relevant vehicle type and relevant vehicle specification. Thus, the vehicle side control unit  100  can only be used as the vehicle information writing tool for the supplemental vehicle side control unit that matches the relevant vehicle type/specification. In this case, the vehicle side ID uniquely set by the DIP switches  364  on the vehicle side control unit  100  that serves as the writing tool is considered as the tool side ID, and is compared with the vehicle side ID in the supplemental vehicle side control unit that is going to have the vehicle information written therein. When the ID is matching, the transfer of the vehicle information is allowed, and, when the ID is not matching, the transfer of the vehicle information is prohibited. 
     Such changes, modifications, and summarized schemes are to be understood as being within the scope of the present disclosure as defined by appended claims.