Apparatus for remote diagnosis of motor vehicles

Abstract

 An apparatus for remote diagnosis of motor vehicles comprising a connecting interface (10) for a connection to a control box (20) of a motor vehicle (21) and a local computer (30) connected to the interface (10) to receive from the control box (20), at least one main signal incorporating a main parameter (301) representative of an operating condition of the motor vehicle (21) and to generate a corresponding auxiliary signal (310) incorporating the main parameter (301); the apparatus (1) further comprises a remote computer (40) provided with receiving means (41) to receive the auxiliary signal (310) from the local computer (30) and a memory (50) for storage of a plurality of reference parameters (51), each associated with a corresponding response parameter (52) representative of an intervention to be carried out on the motor vehicle (21). The remote computer is also provided with a comparing block (60) to compare the main parameter (310) with the reference parameters (51), and with transmitting means (70) to send, depending on said comparison, a response signal (320) incorporating the response parameter (52) to the local computer (30).

Description

[0001] The present invention relates to an apparatus for remote diagnosis of motor vehicles.

[0002] It is known that motor vehicles are provided with electronic control boxes having the task of monitoring operation of the motor vehicle and informing the driver, usually through suitable signal lights, about arising of faults or malfunctions.

[0003] In more detail, the present trend of the market is to plan and introduce vehicles in which the control connections of the engine and the other vehicle members are made through high-speed networks and therefore every electromechanical device (arrows, lights, brakes, conditioner, etc.) internally contains a true control unit that is able to signal possible failures to the main control box in real time.

[0004] When the car's owner goes to a workshop for repair, the operator assigned to the task connects said control box to a local electronic computer (generally a conventional PC) through which a control on the car conditions is carried out so that the necessary servicing and repairing operations can be carried out.

[0005] Alternatively, some constructors presently propose a service for fault detection also using a remote server which co-operates with said local computer to establish the interventions to be carried out.

[0006] However, it is to be noted that each car brand uses control boxes and telecommunication protocols substantially of their own for the purpose of connecting the control box to the computer present in the workshop.

[0007] Therefore, in each workshop, in order that a full service may be supplied also with reference to different car brands and models, the local computer must be provided with a suitable software and sometimes with a suitable hardware associated therewith, for each brand present on the market.

[0008] Consequently, it is apparent that the costs to be borne by the managers of the different workshops are very high, exactly due to the number of apparatus and software programs that must be purchased in order to be able to offer a complete service to customers.

[0009] In addition, each software present on the market requires periodical updating, which obviously involves additional non negligible costs.

[0010] Still with reference to updating, it is also to be noted that in default of updating or if updating is not carried out correctly, due to lack of experience of unqualified mechanical operators in using data processing media, the correct operation of the whole system can be impaired, which will jeopardise the quality of the diagnoses carried out.

[0011] The present invention aims at solving the above mentioned drawbacks.

[0012] In particular, it is an aim of the present invention to make available an apparatus for remote diagnosis of motor vehicles enabling diagnoses to be carried out on motor vehicles of different brands, using a cheap hardware-software architecture which is characterised by a considerable structural simplicity.

[0013] It is a further aim of the present invention to provide an apparatus for remote diagnosis of motor vehicles making the updating operations of the prestored software surer and cheaper.

[0014] The foregoing and further aims are substantially achieved by an apparatus for remote diagnosis of motor vehicles having the features set out in the appended claims.

[0015] Further features and advantages will become more apparent from the detailed description of a preferred but not limiting embodiment of an apparatus for remote diagnosis of motor vehicles illustrated in the accompanying figures, in which:

• Fig. 1 shows a block diagram of the apparatus in accordance with the invention;
• Fig. 2 shows a block diagram of a device used in the apparatus seen in Fig. 1;
• Fig. 3 is a block diagram of another device used in the apparatus seen in Fig. 1;
• Fig. 4 is a block diagram of a further device present in the apparatus seen in Fig. 1;
• Fig. 5 diagrammatically shows the logic structure of a memory used in the device in Fig. 4.

[0016] The apparatus for remote diagnosis of motor vehicles in accordance with the present invention is generally identified with reference numeral 1 in the accompanying drawings.

[0017] Referring particularly to Fig. 1, apparatus 1 comprises a connecting interface 10, a local computer 30 and a remote computer 40.

[0018] It is to be pointed out that the remote computer 40 must be set to co-operate with a plurality of terminals (in the present context identified as local computers 30) so as to define a system of the centralised type in which the remote computer 40 is able to supply its diagnostic capacities together with all stored information relating thereto to each terminal.

[0019] The connecting interface 10 is connected to a control box of a motor vehicle 21 and allows an exchange of signals between the control box 20 itself and apparatus 1 in order to detect possible faults or malfunctions of the motor vehicle 21 and to adjust operation of the devices present on the motor vehicle 21 itself.

[0020] The control box 20 is connected with a plurality of sensors, each of which is associated with a respective device present on board the motor vehicle 21; each sensor has the task of monitoring operation of an electromechanical apparatus of the motor vehicle 21 (arrows, lights, brakes, conditioner, etc., for example) and signalling possible failures to the control box 20.

[0021] For carrying out connection with the control box 20, the connecting interface 10 is provided with a connector 12 having a plurality of electric terminals 12a, each of which is set to engage a respective electric terminal 22 of said control box 20; in this way an electric connection is established between control box 20 and interface 10, which allows an exchange of signals between the sensors present on motor vehicle 21 and apparatus 1.

[0022] The electric terminals 12a of connector 12 (generally called PINs) can be of a varying number, 3 to 16 for example, so that they can adapt themselves to the output ports of the control boxes in vehicles of different brands.

[0023] Therefore, not all the electric terminals 12a will be always used for signal exchange between apparatus 1 and control box 20; for the purpose of selecting the electric terminals 12a that are really necessary for said connection between apparatus 1 and control box 20, the connecting interface 10 comprises an activation block 13 the function of which is to selectively activate, upon reception of a suitable input signal that will be better described in the following, a predetermined number of electric terminals 12a, depending on the requirements of each control box.

[0024] Preferably, the activation block 13 consists of a multiplexer/demultiplexer.

[0025] It is further to be noted that connector 12 can be removably mounted on the interface 10 structure, so that it can be removed or replaced by a different connecting element, should the features of the control box 20 call for it; in this case, the activation block 13 and the remaining circuitry of the interface 10 must be such arranged that interfacing of same with the substitute connector is also possible.

[0026] By means of the logic-circuit structure hitherto described, apparatus 1 is able to receive at least one main signal 300 from the control box 20, which main signal incorporates a main code 302 identifying a given device of motor vehicle 21, and one main parameter 301 representative of an operating condition of said device.

[0027] The contents of the main signal 300 must be then transmitted to the local computer 30; to this aim, the connecting interface 10 is provided with a processing circuit 11 connected with said control box 20 to receive the main signal 300.

[0028] Depending on the type of main signal 300 received, the processing circuit 11 carries out suitable processing of said signal, thereby obtaining a corresponding auxiliary signal 310. The auxiliary signal 310 is then sent to the local computer 30.

[0029] In more detail, the processing circuit 11 is drivable between at least one first and one second operating conditions.

[0030] In the first operating condition the processing circuit 11 carries out a voltage-level translation of the main signal 30, thereby obtaining said auxiliary signal 310. This first operating condition will be typically used if the main signal 300 from the control box 20 is a signal of the serial type.

[0031] In the second operating condition the processing circuit 11 carries out a much more complicated processing of the main signal 300; in fact, the main signal 200 is demodulated, selection of the main parameter 301 and main code 302 is carried out and said codes are incorporated in the auxiliary signal 310, so that they can be received by the local computer 30.

[0032] The second operating condition is activated when the control box 20 is set to transmit information through a CAN protocol; in fact the data received by means of this protocol are not directly insertable in the serial port of the PC 30, and therefore a suitable processing is required to obtain correct transfer of the parameters.

[0033] Practically, the processing circuit 11 can consist of two distinct circuit portions, each dedicated to one of the two above stated operations; the first and second operating conditions of the processing circuit 11 will correspond therefore to a selective use of one of said circuit portions.

[0034] For piloting the processing circuit 11 between the first and second operating conditions, the connecting interface 10 is provided with suitable control means 14 which, depending on the information inputted thereto, carries out activation of the operating condition of the processing circuit 11 that is the most appropriate for each individual case.

[0035] The local computer 30 (Fig. 3) has the function of first of all receiving said auxiliary signal 310 and transmitting it to the remote computer 40; the latter, as better clarified in the following, is set to return a response signal 320, depending on the auxiliary signal 310 received, said response signal 320 incorporating a response parameter 52 representative of an intervention to be carried out on said vehicle 21.

[0036] The response signal 320 is received by the local computer 30 that will carry out selection of the information contained in the response signal 320 and process it in a suitable manner. In fact, the local computer 30 is first of all provided with displaying means 32 to display said response parameter 52, if required; in this manner, the necessary instructions can be directly supplied to an operator that is positioned in the vicinity of the local computer 30.

[0037] The local computer 30 is further provided with a transfer block 33 designed to select the response parameter 52 present in the response signal 320 and transmit it to the connecting interface 10; in this way, the control box 20 can be directly supplied with a command or adjustment signal to automatically carry out servicing or setting operations on the devices present on motor vehicle 21.

[0038] The local computer 30 further comprises transmitting means 34 designed to select, within the response signal 320, the first and second parameters 55a, 55b and to transmit them to the connecting interface 10; in more detail, the first parameter 55a is sent to the command means 14 to enable the same to suitably pilot the processing circuit 11, whereas the second parameter 55b is sent to the activation block 13 to enable the latter to select the electric terminals 12a of connector 12 depending on the user's requirements.

[0039] The local computer 30 generally consists of a conventional PC, and is located within the workshop at which repair or servicing of vehicle 21 is to be carried out; advantageously, communication between the interface 10 and local computer 30 takes place through wireless technology and, more particularly, through use of the BlueTooth protocol. Therefore, both the interface 10 and the local computer 30 are provided with a suitable connecting module (not shown in the accompanying drawings) allowing physical connecting means for data exchange not to be used.

[0040] It is apparent that use of these technologies gives the whole system a great flexibility and adaptability of use.

[0041] The local computer 30 can be embodied either (as above mentioned) by a conventional PC, or by a less sophisticated terminal exclusively provided with the necessary hardware for implementation of the above described functions.

[0042] In addition, the local computer 30 may also comprise suitable communication means both of the visual and verbal type, to supply additional information to the remote computer 40 and the person operating close thereto.

[0043] By way of example, it is to be considered in this connection a webcam for transmission of images and films in a digital format from the workshop where the local computer 30 is and the hardware-software packages capable of enabling a vocal communication between the operator at the workshop and the person operating with the remote computer 40; the latter will be obviously provided with the necessary technology for reception of said information.

[0044] The remote computer 40, as above mentioned, receives the auxiliary signal 310 and outputs a response signal 320, to supply the control box 20 and/or the operator present at the workshop with the necessary information for intervention on motor vehicle 21.

[0045] The remote computer 40 first of all comprises a memory 50 on which all data necessary for identification of motor vehicle 21 and a correct servicing or repair of the same are stored.

[0046] In more detail, as diagrammatically shown in Fig. 5, memory 50 first of all comprises a plurality of tables 54 each of which contains a plurality of identification codes 53, each of said codes being associated with a corresponding reference parameter 51 and a corresponding response parameter 52; practically, said tables 54 are each defined by an ordered succession of lines each of which contains an identification code 53, a reference parameter 51 and a response parameter 52.

[0047] Each of tables 54 refers to a predetermined motor vehicle brand, and the data therein contained are used for servicing and repair of the different models of said brand; tables 54, as better clarified in the following, are selected each time depending on a command signal entered by the operator by means of the local computer 30.

[0048] Each identification code 53 indicates a given device present on vehicle 21; in this way within memory 50 and the related tables 54 the rectified parameters for each device can be found.

[0049] The reference parameters 51 can consist of either individual values or ranges defined by their end values; these reference parameters 51 are representative of the correct operation of the device to which they refer.

[0050] By comparing the information from the control box 20 and the suitably selected reference parameters 51, it is therefore possible to detect failures and malfunctions.

[0051] The response parameters 52 are on the contrary representative of interventions that must be carried out on motor vehicle 21 when problems arise; the response parameters 52 can be simple instructions for the person operating in the workshop where the local computer 30 is, or adjustment signals that, transmitted to the control box 20, enable automatic servicing of the devices connected thereto.

[0052] Memory 50 is further provided with a setting register 55 in which a plurality of first parameters 55a and second parameters 55b is stored. Each pair defined by a first parameter 55a and the second parameter 55b associated therewith is used to set operation of interface 10, depending on the type of motor vehicle 21 to be repaired.

[0053] The first parameter 55a is representative of an operating condition of the processing circuit 11; practically, the first parameter 55a states, at the vehicle with which it is associated, whether the processing circuit 11 must operate in the first or in the second operating conditions for data exchange with the control box 20.

[0054] The second parameter 55b defines, still depending on the type of vehicle taken into consideration, which electric terminals 12a must be used for a physical connection between connector 12 and the I/O port of the control box 20.

[0055] The remote computer 40 further comprises a receiving block 42 to receive a selection command 330, entered by the user by means of said local computer 30; the selection command 330 practically consists of one or more data for univocal identification of motor vehicle 21, so that the system diagnosis can be carried out correctly.

[0056] In a preferred embodiment, the selection command 330 can be defined by the motor vehicle frame number; in this case, memory 50 will be provided with an appropriate database, updated with the information progressively sent from the different constructors, in which all frame numbers of the circulating cars are added.

[0057] In this manner with each motor vehicle it is possible to associate a first and a second parameters 55a, 55b and a series of identification codes 53, reference parameters 51 and response parameters 52 relating to devices present on the motor vehicle itself.

[0058] The remote computer 40 further comprises a first selection circuit 44 connected to the receiving block 42 for the purpose of selecting within the setting register 55, the first and second parameters 55a, 55b concerning the motor vehicle identified by the selection command 330.

[0059] A transmitting block 46 connected with the first selection circuit 44, carries out incorporation of the selected first and second parameters 55a, 55b into a setting signal 340 that is then sent to the interface 10 through the local computer 30. In this way, the control means 14 and activation block 13 can receive the first and second parameters 55a, 55b respectively and thus adjust the processing circuit 11 and connector 12.

[0060] A second selection circuit 45 carries out selection of a table 54 in memory 50, still based on the selection command 330, so that the comparison operations to be described in the following can be correctly performed.

[0061] The remote computer 40 is also provided with receiving means 41 connected to the local computer 30 to receive the auxiliary signal 310 therefrom, which signal like the main signal 300 incorporates a main code 302 and a main parameter 301.

[0062] The remote computer 40 is further provided with a comparing block 60 connected to both the receiving means 41 and memory 50; in this manner, the comparing block 60 can compare the data contained in the main signal 300 with those stored on memory 50 in order to evaluate the conditions of the examined devices by means of the control box 20 and interface 10.

[0063] In more detail, selecting means 80 selects a reference parameter 51 and a response parameter 52 depending on the main code 302; the comparing means 60 then compares the main parameter 301 with the selected reference parameter 51. Depending on the outcome of said comparisons, transmitting means 70 suitably associated with the comparing block 60 will send the response signal 320 to the local computer 30; this response signal in particular shall contain at least the previously selected response parameter 52.

[0064] From the point of view of operation, the following is to be pointed out as regards apparatus 1.

[0065] When a motor vehicle 21 is taken to the workshop where the local computer 30 is, connection between the local computer 30 and the control box 20 of the motor vehicle 21 is obtained by means of the connecting interface 10.

[0066] First of all, the operator enters a selection command 330 into the local computer 30, to enable the system to identify motor vehicle 21 in an univocal manner and carry out a correct diagnosis; in particular, as above mentioned, the selection command can consist either of the car frame number or, alternatively, of a sequence of data concerning the brand, model and specific characteristics of the vehicle itself.

[0067] The selection command 330 is transmitted to the remote computer 40 receiving it through the receiving block 42 and using the information contained in this signal for activating the different procedures that will lead to the execution of a diagnosis.

[0068] Firstly, through the first selection circuit 44 the first and second parameters 55a, 55b corresponding to motor vehicle 21 are selected within the setting register 55; the first and second parameters 55a, 55b are then incorporated into a setting signal 340 that, through the local computer 30, is sent to the connecting interface 10.

[0069] The first parameter 55a, in particular, is inputted to the control means 14 so that the processing circuit 11 can be piloted in the required operating condition for the specific case; the second parameter 55b is sent to the activation block to select the electric terminals 12a of connector 12 necessary for physical connection with the control box 20.

[0070] It is to be noted that a preliminary communication step can be also carried out before the remote computer 40 generates and outputs the setting signal 340; during this preliminary step the remote computer 40, depending on the received selection command, transmits a predetermined number of preliminary information to the local computer 30, which information concerns the type of connector to be used for example, and other practical expedients to be adopted to set connection between the interface 10 and control box 20.

[0071] The thus transmitted preliminary information is displayed through the displaying means 32 of the local computer 30, so that the operator can receive the necessary instructions to perform the connecting operations.

[0072] Depending on the selection command 330 one of the tables 54 contained in memory 50 is also selected, so that the identification codes 53, reference parameters 51 and response parameters 52 concerning motor vehicle 21 are conveniently set for subsequent processing.

[0073] In the light of the above, it is apparent that to each table 54 a first and a second parameters 55a, 55b correspond; in other words, with reference to the same vehicle, the first and second parameters 55a, 55b define the modalities for connection between interface 10 and control box 20, whereas the data contained in table 54 associated with said first and second parameters 55a, 55b are used for obtaining the diagnosis concerning said vehicle.

[0074] Once connection between apparatus 1 and control box 20 has been established, said control box transmits the main signal 300 containing a main code 302 and a main parameter 301 to the interface 10. The interface 10, by means of the processing circuit 11, processes the main signal 300 and obtains the corresponding auxiliary signal 310.

[0075] The data contained in the two signals are substantially the same (main code 302 and main parameter 301); the only difference resides in the physical characteristics of the two signals. In fact, to enable the auxiliary signal 310 to be entered into the local computer 30 (and to be subsequently sent to the remote computer 40 at a sufficiently high speed) said signal must be of the serial type defined between predetermined voltage levels; the main signal 300 outputted from the control box 20 can be, on the contrary, of two different types.

[0076] A first main signal can be of the serial type, but defined between different voltage levels with respect to those required by the local computer 30; therefore, in this case the processing circuit 11 will be set to its first operating condition and will carry out the necessary translation of the voltage values, so as to adapt the received signal to the requirements of the local computer 30.

[0077] A second type of main signal 300 can be generated in accordance with the CAN protocol; in this second case, the main signal 300 does not contain the main code 302 and main parameter 301 alone, but it will also contain a series of additional information typical of said protocol.

[0078] The processing circuit 11 will be then set to its second operating condition, so that the CAN signal can be demodulated, the two data of interest read out and the auxiliary serial signal 310 generated for transmission to the local computer 30.

[0079] Once the local computer 30 has received the auxiliary signal 310, it immediately transmits it again to the remote computer 40 without carrying out any additional processing, so as to minimise the time used for exchange of information.

[0080] Connection between the local computer 30 and remote computer 40 can be obtained through the Internet for example (such as with a DSL connection) or by means of any other type of telematic network enabling remote communication between different computers; by way of example, technologies for mobile phones such as GSM, GPRS and UMTS are considered.

[0081] The remote computer 40 then receives the auxiliary signal 310 and the parameters incorporated thereinto; afterwards a comparison is carried out between the received data and those previously stored to evaluate the conditions of vehicle 21.

[0082] In particular, the main code 301 is compared with the identification codes 53 present in the previously selected table 54; should the main code 302 be the same as a given identification code 53, the selecting means 80 selects the reference parameter 51 and response parameter 52 associated with such an identification code 53 in table 54.

[0083] Practically, with the above described comparison the device of motor vehicle 21 to which the main signal 300 sent from the control box 20 refers, is recognised and in addition the suitable parameters for continuation of the diagnosis are selected.

[0084] The reference parameter 51 is then compared by the comparing block 60 with the main parameter 301; thus it is ascertained whether the device under examination has faults or failures.

[0085] The reference parameter 51 in fact represents a value (or a value range) relating to a correct operation of the device; should the main parameter 301 greatly diverge from these values, an intervention on vehicle 21 would be required. Therefore, in the last-mentioned case the transmitting means 70 generates the response signal 320 containing the response parameter 52 selected as above stated.

[0086] The response parameter can substantially be of two types. A first response parameter 52 consists of a series of information to be displayed on the displaying means of the local computer 40 to guide the operator in carrying out the necessary steps for repair.

[0087] A second response parameter 52 can be instead defined by one or more adjustment values that, directly transmitted to the interface 10 and therefrom to the control box 20, allow an automatic action of the control box itself on the concerned device.

[0088] In the light of the above, it clearly appears that the function of the local computer 30 is almost exclusively that of a repeater, set to receive signals from the control box 20 and to transmit them to the remote computer 40 or, vice versa, to receive signals from the remote computer 40 and transmit them to the control box 20, without adding additional processing operations to those carried out by the remote computer 40.

[0089] The operations described above with reference to a single main signal 300, can be obviously repeated many times taking into account the same device of motor vehicle 21 or different devices suitably identified by the main code 302 associated therewith, so as to obtain a full diagnosis of motor vehicle 21.

[0090] It will be appreciated that data exchange between the different functional blocks described above must be carried out at high speed; in fact for a remote transmission (to the remote computer 40) of information from the control box 20, connection between the control box 20 and apparatus 1 remains always active, in order to avoid repeated new activations (that can for example consist of switching off and subsequent new switching on of the vehicle instrument board), which is clearly time-consuming.

[0091] In more detail, a maximum time T_max is defined that represents a limit value of the sum of the different delays introduced into the steps carried out in succession in order to obtain the analysis of the car conditions. The relation that must be complied with for an optimal operation of the system is the following:

wherein:

T_int represents the delay introduced by the connecting interface 10;

T_pc-off represents the delay introduced by the local computer 30;

T_line represents the delay introduced by the communication line for connection between the local computer 30 and remote computer 40;

T_ced represents the delay due to processing carried out by the remote computer 40.

[0092] In order to cause the delays introduced into the different transmission and processing steps to remain under the predetermined threshold, it is provided that both the remote computer 40 and the local computer 30 be controlled through "interrupt" procedures or by means of the NT technology in the Windows operating system, which will enable a particularly precise management of the defined hierarchy between the operations that each machine has to carry out.

[0093] Conveniently, the remote computer 40 can therefore define a centralised structure, even at a national level, to which all workshops through respective local computers 30 and the connecting interfaces 10 associated therewith can be connected to carry out diagnoses on cars of any brand.

[0094] In addition to the above, the remote computer 40 can be provided with a suitable storage register to contain the information relating to each diagnosis carried out and in this way create a history file of the digital type of the various operations performed; this file is particularly advantageous because it enables the speed, accuracy and reliability of the diagnoses subsequently carried out to be improved, exactly due to the possibility offered to the remote computer 40 to get information from a wide database with which the information concerning each case under examination can be compared.

[0095] The invention achieves important advantages.

[0096] First of all, by means of the above described structure a remote diagnosis system for motor vehicles can be obtained which is capable of operating in a precise and correct manner on motor vehicles of all the brands present on the market.

[0097] This system in addition has a simple and cheap hardware-software structure above all with reference to the set of instruments that each operator working in a workshop must have at his/her disposal.

[0098] In addition, due to remote control and transmission of most of the prestored information and of the substantial processing operations that must be carried out for diagnosis, updating of the different databases is greatly simplified and the related costs drastically reduced.

[0099] A further advantage is found in the limited bulkiness of the instruments present in each workshop; in fact, with only the connecting interface 10 and a conventional PC it is possible to operate on any brand of vehicles.

Claims

1. An apparatus for remote diagnosis of motor vehicles, comprising:

- a connecting interface (10) for a connection between said apparatus (1) and a control box (20) of a motor vehicle (21);

- a local computer (30) connected to said interface (10) to receive at least one main signal (300) from said control box (20), said main signal incorporating a main parameter (301) representative of an operating condition of said motor vehicle (21), and to generate a corresponding auxiliary signal (310) incorporating at least said main parameter (301),

characterised in that it further comprises:

- a remote computer (40) provided with:

- receiving means (41) connected with said local computer (30) to receive said auxiliary signal (310) therefrom;

- a memory (50) to contain a plurality of reference parameters (51), associated each with a corresponding response parameter (52), the latter being representative of an intervention to be carried out on said motor vehicle (21);

- a comparing block (60) connected to said receiving means (41) to compare said main parameter (301) with said reference parameters (51);

- transmitting means (70) connected to said comparing block (60) to send a response signal (320) incorporating said response parameter (52) to said local computer (30), depending on said comparison.

2. An apparatus as claimed in claim 1, characterised in that said memory (50) further contains a plurality of identification codes (53), each of them being representative of a corresponding device of said motor vehicle (21) and being associated with a respective reference parameter (51) and the corresponding response parameter (52).

3. An apparatus as claimed in claim 2, characterised in that said main signal (300) further incorporates a main code (302) representative of a corresponding device of said motor vehicle (21), said main parameter (301) being in particular representative of an operating condition of said corresponding device, said auxiliary signal (320) also incorporating said main code (302).

4. An apparatus as claimed in claim 3, characterised in that said remote computer (40) is further provided with selecting means (80) connected with said receiving means (41) to compare said main code (302) with said identification codes (53), and to select the reference parameter (51) and response parameter (52) associated with said identification code (53) that is substantially the same as said main code (302), said comparing block (60) comparing the main parameter (302) with the selected reference parameter (51), said response signal (320) incorporating the selected response parameter (52).

5. An apparatus as claimed in anyone of the preceding claims, characterised in that said memory (50) comprises a plurality of tables (54), each of them being associated with a corresponding brand of motor vehicles (21), each of said tables (54) containing:

- a plurality of identification codes (53), each being representative of a respective device of a motor vehicle of said corresponding brand;

- a plurality of reference parameters (51), associated each with a respective identification code (53);

- a plurality of response parameters (52), associated each with a corresponding identification code (53) and with the reference parameter (51) associated therewith, each of said response parameters (52) being representative of an intervention to be carried out on a motor vehicle (21) of said corresponding brand,

said tables (54) being selectively identified depending on a selection command (330) entered by said operator into said local computer (30), the latter being provided with a transmitting block (31) to send said selection command (330) to said remote computer (40).

6. An apparatus as claimed in anyone of the preceding claims, characterised in that said local computer (30) is further provided with displaying means (32) to display said response parameter (52).

7. An apparatus as claimed in anyone of claims 1 to 5, characterised in that said local computer (30) further comprises a transfer block (33) to receive said response signal (320) and send at least the response parameter (52) incorporated in said response signal (320) to said control box (20).

8. An apparatus as claimed in anyone of the preceding claims, characterised in that said connecting interface (10) comprises a processing circuit (11) connected to said control box (20) to receive said main signal (300) and transmit said auxiliary signal (310) to said remote computer (40), said processing circuit (11) being drivable between a first operating condition, at which it carries out a voltage-level translation of said main signal (300) to obtain said auxiliary signal (310) and a second operating condition at which it demodulates said main signal (300) to select said main parameter (301) and incorporate it into said auxiliary signal (310).

9. An apparatus as claimed in anyone of the preceding claims, characterised in that said interface (10) further comprises:

- a connector (12) having a plurality of electric terminals (12a) suitable for connection to corresponding electric terminals (22) of said control box (20) to receive said main signal (300) and preferably send said response parameter (52) to said control box (20);

- an activation block (13) preferably defined by a multiplexer/demultiplexer, to select a predetermined number of said electric terminals (12a) in order to receive said main signal (300) and preferably send said response parameter (52) to said control box (20).

10. An apparatus as claimed in claims 8 and 9, characterised in that said memory (50) is further provided with a setting register (55) having, for each of said motor vehicle brands, a first parameter (55a) representative of an operating condition of said processing circuit (11) and a second parameter (55b) representative of the electric terminals (12a) to be selected through said activation block (13).

11. An apparatus as claimed in claim 10, characterised in that said remote computer (40) further comprises:

- a receiving block (42) to receive said selection command (330);

- a first selection circuit (44) connected with said receiving block (42) to select said first and second parameters (55a, 55b) in said setting register (55), depending on said selection command (330);

- a transmitting block (46) connected to said first selection circuit (44) to generate a setting signal (340) incorporating said selected first and second parameters (55a, 55b) and intended for said interface (10);

- a second selection circuit (45) to select a predetermined one of said tables depending on said selection command (330).

12. An apparatus as claimed in claim 1, characterised in that said local computer (30) comprises transmitting means (34) to receive said response signal (320) and transmit said second parameter (55b) to the activation block (13) of said interface (10), to enable said activation block (13) to select said electric terminals (12a) depending on said second parameter (55b).

13. An apparatus as claimed in claim 11 or 12, characterised in that said interface (10) further comprises control means (14) connected to said local computer (30) to receive said first parameter (55a) and pilot said processing circuit (11) between the first and second operating conditions, depending on said first parameter (55a).

Drawing