Communication interface between a diagnostic tool and a motor vehicle.

Abstract

A method for managing communication between a motor vehicle and a remote vehicle diagnostic system installed on a computer not part of the motor vehicle. This method allows for the replacement of a physical communication interface with a virtual communication interface and the use of a simple OBD-Ethernet cable (401) to connect the computer to the vehicle. By emulating steps of the DoIP communication protocol, the method enables diagnostics by directly transmitting commands from the remote diagnostic system to a gateway in the vehicle. The gateway then redirects the commands to the relevant local diagnostic systems.The system according to the invention then receives responses from local diagnostic systems and transmits them to the remote diagnostic system. Figure for the abstract: 1.

Description

Title of the invention: Communication interface between a diagnostic tool and a motor vehicle.

[0001] The invention relates to a communication interface between a diagnostic tool and a motor vehicle. The invention further relates to a diagnostic tool equipped with such an interface.

[0002] The use of a diagnostic software tool is essential for the maintenance and repair of a motor vehicle. Such a tool makes it possible, for example, to check the condition and operation of the vehicle's computers or to verify the initial state of the vehicle before carrying out complex operations, such as a software update.

[0003] The diagnostic software tool is advantageously installed on a laptop computer. Hardware and software communication means, known as VCI (Vehicle Communication Interface), are implemented to allow communication between the diagnostic software tool installed on the computer and diagnostic software tools installed on the motor vehicle.

[0004] Motor vehicles are evolving towards increasingly complex systems, leading to changes in their electrical and electronic architecture. This evolution creates, in particular, a need for increased performance in the communication networks implemented within the vehicle or between the vehicle and its environment.

[0005] However, the hardware and software communication methods currently in use have drawbacks. In particular, the technical solutions currently implemented are expensive and rely on the use of a specific interface managing communication between the computer and the various electronic control units of the vehicle.

[0006] The object of the invention is to provide a system and a method implementing a communication interface between a diagnostic tool installed on a computer and diagnostic tools installed on a motor vehicle, the system and the method overcoming the drawbacks of existing communication interfaces between a diagnostic tool installed on a computer and diagnostic tools installed on a motor vehicle. In particular, the communication interface according to the invention is simple, efficient, and inexpensive to implement.

[0007] To this end, the invention relates to a method for managing communication between a motor vehicle and a remote diagnostic system for the motor vehicle installed on a computer not forming part of the motor vehicle, the motor vehicle comprising: - a first plurality of subsystems, including vehicle computers, - a second plurality of local diagnostic systems, each local diagnostic system being capable of providing a diagnosis of the state of at least one subsystem of the first plurality, - a central system, called the "central gateway", capable of communicating: (i) on the one hand with each local diagnostic system of the second plurality of local diagnostic systems, and (ii) on the other hand with the remote diagnostic system, according to a "diagnostic over IP" communication protocol. Furthermore, the process includes: - a step of connecting an OBD-Ethernet cable between the motor vehicle and the computer, including connecting one end of the OBD-Ethernet cable, which includes an Ethernet connector, to a connector on the computer, and connecting one end of the cable, which includes an OBD connector, to a connector on the motor vehicle, then - a configuration step, within the computer, of communication methods capable of enabling, via the OBD-Ethernet cable, the sending of messages to the central gateway of the motor vehicle and the reception of messages from the central gateway of the motor vehicle, then - a step of establishing communication between the remote diagnostic system and the central gateway, by executing on the computer a system emulating steps of the "diagnostic over IP" communication protocol between the remote diagnostic system and the central gateway.

[0008] In one embodiment, the step of configuring communication means capable of enabling, via the OBD-Ethernet cable, the sending of messages to the central gateway of the motor vehicle and the reception of messages from the central gateway of the motor vehicle comprises: - establishing an Ethernet connection between the computer and the central gateway of the motor vehicle, and - the creation of an initial TCP socket linked to an IP address and port associated with the remote diagnostic system, and - the creation of a second TCP socket attached to an IP address and a port associated with the central gateway.

[0009] In one embodiment, the step of establishing communication between the remote diagnostic system and the central gateway includes successive emulation, by an emulation system, of messages intended for the central gateway – a first message emulating a vehicle identification message, then - a second message emulating a routing activation message, reception of the second message by the central gateway inducing the creation by the central gateway of a TCP socket attached to an IP address and a port associated with the central gateway, then - a third message emulating a check of the central gateway's ability to respond to requests from the remote diagnostic system, then - a fourth message emulating a check of the central gateway's status.

[0010] In one embodiment, the method further comprises, following the step of establishing communication between the remote diagnostic system and the central gateway, a diagnostic step of at least one subsystem of the first plurality of subsystems, the diagnostic step comprising: - a first sub-step of selecting at least one subsystem of the first plurality to be diagnosed, then - a second sub-step of determining, for each at least one selected subsystem, one or more diagnostic operations to be performed, - then, a third sub-step of transmission by the remote diagnostic system of a command message of a first type to the emulation software via the first socket, the command message of a first type containing the diagnostic operations to be performed for each at least one subsystem selected from the first plurality of subsystems, - then, a fourth sub-step comprising: (i) generation by the emulation system of at least one command message of a second type respectively intended for at least one local diagnostic system associated with at least one selected subsystem, then ii) a transmission by the emulation system of at least one command message of a second type via the second socket to the central gateway, - then, a fifth sub-step comprising: i) a reception by the central gateway, via the second socket, of at least one command message of a second type, then ii) transmission, via the central gateway, of at least one command message of a third type to at least one selected local diagnostic system, then iii) reception, by at least one selected local diagnostic system, of at least one command message of the third type, then (iv) transmission, by at least one selected local diagnostic system, of a first-type response message to the central gateway, and then, a sixth sub-step comprising: i) a transmission, via the central gateway, through the second socket, of a response message of a second type to the emulation system, ii) then a transmission by the emulation system, via the first socket, of a third type response message to the remote diagnostic system.

[0011] In one embodiment, each command message of a second type created by the emulation software is structured according to the Diagnostic Over IP protocol, in particular each command message of a second type includes: - a message sending address, corresponding to an IP address of the remote diagnostic system, - a message destination address, corresponding to an IP address of a subsystem of the first plurality to be diagnosed, and - command messages in UDS format, which are generated by the emulation software.

[0012] In one embodiment, a response message of a first type from at least one selected local diagnostic system and transmitted to the central gateway is coded in binary format, and the transmission, by the emulation system, of a response message to the remote diagnostic system includes a conversion of the response message of a second type received by the emulation system, into a response message of a third type in hexadecimal format.

[0013] In one embodiment, the substep of selecting at least one subsystem of the first plurality to be diagnosed, and / or the substep of determining, for each at least one selected subsystem, one or more diagnostic operations to be performed, are implemented via a human-machine interface communicating with the remote diagnostic system.

[0014] The invention further relates to a method for diagnosing a motor vehicle comprising a step of implementing a method for managing communication between the motor vehicle and a diagnostic system according to the invention.

[0015] The invention also relates to a motor vehicle diagnostic device, comprising a motor vehicle and a remote motor vehicle diagnostic system installed on a computer not part of the motor vehicle, the device comprising means for implementing the diagnostic process according to the invention and / or means for implementing the management process according to the invention.

[0016] The attached drawing represents, by way of example, an embodiment of a communication interface according to the invention.

[0017] Figure 1 represents an embodiment of a system 1 according to the invention comprising - a motor vehicle 10, - a remote diagnostic system 20 of the motor vehicle 10, - a computer 30 not forming part of the motor vehicle 10, the remote diagnostic system 20 being installed on the computer 30, and - means 40 for implementing communication between the motor vehicle 10 and the remote diagnostic system 20.

[0018] The motor vehicle 10 comprises - a first plurality 101 of motor vehicle subsystems, - a second plurality 102 of local diagnostic systems, a local diagnostic system of the second plurality being capable of providing a diagnosis of the state of at least one subsystem of the first plurality 101, - a central system 103, called the "central gateway", capable of communicating (i) on the one hand with each local diagnostic system of the second plurality 102, and (ii) on the other hand with the remote diagnostic system 20, according to a "diagnostic over IP" communication protocol.

[0019] In the remainder of this document, the local diagnostic systems of the second plurality 102 are referred to as "local diagnostic systems 102"

[0020] In one embodiment, the central gateway 103 is implemented by a computer of the motor vehicle 10.

[0021] The first plurality of subsystems 101 may include, for example: - a 1011 system for managing a traction motor of the motor vehicle 10, and / or - a 1012 system for managing exhaust gas emissions, and / or - a 1013 braking system.

[0022] In the remainder of this document, the term "diagnostics over IP" refers to a communication protocol used in the automotive industry for diagnosing vehicles via standard IP networks. This communication protocol allows diagnostic information to be transferred over IP networks, making it possible to diagnose and update vehicle systems remotely.

[0023] In the remainder of this document, the local diagnostic systems of the second plurality 102 are referred to as "local diagnostic systems 102". A local diagnostic system 102 is software implemented by a computer of the motor vehicle 10 to check the operation of one or more subsystems 1011, 1012, 1013 of the motor vehicle 10.

[0024] In one embodiment, the central gateway 103 is implemented by a computer of the motor vehicle 10. The central gateway 103 is a key element in the electronic architecture of the motor vehicle 10, in particular the gateway The central gateway interconnects the vehicle's various electronic subsystems, enabling communication between them while ensuring the security and efficiency of data flow. In other words, it links the different networks within the vehicle, allowing them to communicate even if they use different communication protocols. Furthermore, the central gateway implements secure message routing between the vehicle's various subsystems.10

[0025] In the described embodiment, the computer 30 is capable of running remote vehicle diagnostic software 301 and emulation software 302 for a communication protocol between the remote diagnostic software 301 and the central gateway 103. In one embodiment, the software 302 is implemented using a Python script. Optionally, the emulation software 302 could be integrated into the diagnostic software 301.

[0026] In the remainder of this document, the term "emulation" is used to refer to the reproduction of the behavior of a system or software. The emulation software 302 allows the remote diagnostic system to communicate with the central gateway 103 using a communication protocol that gateway 103 is capable of handling.

[0027] The means for implementing communication between the motor vehicle 10 and the computer 30 include, in particular: - an OBD-Ethernet 401 cable, - the 302 emulation software.

[0028] The OBD-Ethernet cable 401 is designed to connect the motor vehicle 10 equipped with an OBD-II port (i.e. a standardized "On-Board Diagnostics" port), to another device with an Ethernet port, in particular to the computer 30 on which the remote diagnostic system 20 is installed.

[0029] An embodiment of an OBD-Ethernet 401 cable is illustrated in [Fig. 2]. The 401 cable is shown as an electronic wiring diagram representing a connection between a male RJ45 connector 4011 and a component 4012, which may be a microcontroller or an integrated circuit. The 4011 connector is an Ethernet connector. Pins 1, 2, 3, and 6 of the 4011 connector are connected to pins 3, 11, 12, and 13 of the 4012 component, respectively.

[0030] Communication between the plurality 102 of local diagnostic systems of the motor vehicle 10 and the remote diagnostic system 20 is carried out via the central gateway 103 of the motor vehicle 10. In particular, via the OBD-Ethernet cable 401, the central gateway 103 is able to communicate with the remote diagnostic system 20 according to a diagnostic over IP protocol (called DoIP).

[0031] The emulation software 302 is also implemented by the remote computer 30 in order to: - to emulate the steps involved in establishing communication between the remote diagnostic system 20 installed on the remote computer and the central gateway 103 installed on the motor vehicle 10, and - to manage the format conversion of messages passing between the remote diagnostic system 20 and the local diagnostic systems of the second plurality 102.

[0032] The central gateway 103 is also capable of communicating with local diagnostic systems via a vehicle communication interface, referred to hereafter as the "VCI interface". The VCI interface can incorporate various protocols and devices enabling the exchange of information between the central gateway 103 and the local diagnostic systems 102.

[0033] After communication is established between the remote diagnostic system 20, running on the computer 30, and the central gateway 103, the central gateway 103 is able to transmit requests from the remote diagnostic system 20 to the local diagnostic systems 101. The requests are transmitted in UDS (Unified Diagnostic Services) format. The central gateway 103 is also able to receive responses from the local diagnostic systems and to transmit these responses to the remote diagnostic system 20.

[0034] The system 1 according to the invention thus comprises the hardware and software means for implementing a method of managing communication between the remote diagnostic system 20 and the local diagnostic subsystems 102.

[0035] The management process according to the invention comprises the steps E1 to E5 described below, which take place successively.

[0036] In a first step 11, an OBD-Ethernet cable is connected between the motor vehicle 10 and the computer 30, comprising - a connection, to a connector on computer 30, of one end of the cable comprising an Ethernet connector, and - a connection, to a connector of the motor vehicle 10, of one end of the cable comprising an OBD connector.

[0037] In the remainder of this document, the OBD-Ethernet cable may be referred to as "cable 401".

[0038] Then we proceed to a second configuration step E2, in the computer, of means of communication capable of enabling, via cable 401, the sending of messages to the central gateway 103 of the motor vehicle 10 and the reception of messages from the central gateway 103 of the motor vehicle.

[0039] The second step E2 advantageously comprises - a sub-step E21 for establishing an Ethernet connection between the computer 30, including the remote diagnostic software 301, and the central gateway 103 of the motor vehicle 10, - a sub-step E22 for creating a first TCP socket, named "socket 402" in the rest of the document, linked to an IP address and a port associated with the remote diagnostic system 20, and - a sub-step E23 of creating a second TCP socket, named "socket 403" in the rest of the document, attached to an IP address and a port associated with the central gateway 103.

[0040] Then we proceed to a step E3 of establishing a communication between the remote diagnostic system 20 and the central gateway 103, by executing on the computer a system emulating steps of the communication protocol "diagnostic over IP" between the remote diagnostic system 20 and the central gateway 103. For this, the emulation system 302 implements a successive emulation of four messages M1, M2, M3, M4 intended for the central gateway 103.

[0041] As illustrated by [Fig.3], - a first message, Ml, emulates a vehicle identification message, then - a second M2 message emulates a routing activation message; reception of the second message by the central gateway 103 induces the creation by the central gateway 103 of the second TCP socket 403 attached to an IP address and a port associated with the central gateway 103, then - a third message M3 emulates a check of the ability of the central gateway 103 to respond to requests from the remote diagnostic system 20, then - a fourth message M4 emulates a check of a state of the central gateway 103.

[0042] In one embodiment, a vehicle identification message Ml identifies the vehicle in question, notably through the vehicle identification number or other identifying information such as the vehicle model or year of manufacture. The Ml message ensures that the diagnostic is indeed performed on the vehicle to be diagnosed and allows the diagnostic software to adapt its operations according to the specific characteristics of the vehicle.

[0043] In one embodiment, a routing activation message M2 enables the central gateway 103 to activate the routing of information between the remote diagnostic system 20 and the local diagnostic systems 102, ensuring that the data flow passes through the central gateway 103.

[0044] In one embodiment, an M3 message, verifying the capacity of the central gateway 103 to respond to requests, aims to ensure that the The gateway is capable of processing diagnostic requests sent by the remote diagnostic system 20 and responding to them correctly. Emulating the M3 message allows for a kind of connectivity or operational status test, ensuring that the central gateway 103 is ready to transmit the information requested by the remote diagnostic system 20.

[0045] In one embodiment, a gateway status check message M4 allows verification that the central gateway 103 is functioning correctly, for example that the central gateway 103 is connected to the local diagnostic systems 102.

[0046] In one embodiment, the method according to the invention further comprises a fourth step E4 illustrated by [Fig. 4]. In step E4, a communication process is implemented between - an emulation software 302, - a remote diagnostic software 301, and - the second plurality 102 of local diagnostic systems relating to the first plurality of subsystems of the motor vehicle 10, the means of implementing communication including the first and second socket-TCP 402, 403 and the central gateway 103 of the motor vehicle 10.

[0047] The description of the sequence of steps E4 refers to various so-called "command" messages and so-called "response" messages - the term "command message" referring to a message containing information relating to a diagnostic request on at least one subsystem of the motor vehicle 10, - the term "response message" referring to a message containing information relating to diagnostic results of at least one diagnosed subsystem.

[0048] Reference is also made to different types of command messages and different types of response messages, for example, "a command message of the first type" and "a command message of the second type." The notion of "command message type" or "response message type" is used to signify that the format of a message changes as it travels between the 302 emulation software and a subsystem of the motor vehicle.

[0049] Thus, the expression "a command message of a first type" means "a command message defined according to a first format," or "a command message encoded according to a first format." For example, the "format" may refer to an encoding of a message in binary format, or in hexadecimal format.

[0050] In a first substep E41, the remote diagnostic system 20 selects subsystems 1011, 1012, 1013 of the motor vehicle from which it wishes to perform the diagnosis. The selection of the subsystems to be diagnosed can be done automatically by the remote diagnostic system 20; alternatively or in addition, the selection of the subsystems to be diagnosed can be done manually by an operator using a human-machine interface 303 implemented by the computer 30. The first substep E41 advantageously includes sending a message M41 between the human-machine interface 303 and the remote diagnostic system 20, the message M41 including the selection of the subsystems to be diagnosed 1011, 1012, 1013.

[0051] Next, in a second substep E42, one or more diagnostic operations to be performed are automatically or manually selected for each subsystem 1011, 1012, 1013. For example, the diagnostic operation could be an error code reading. The second substep E42 advantageously includes sending M42 messages between the human-machine interface 303 and the remote diagnostic system 20, the M42 messages containing the respective selections of the diagnostic operations to be performed on each of the subsystems to be diagnosed 1011, 1012, 1013.

[0052] Next, in a third sub-step E43, the remote diagnostic system 20 sends a command message M43 of a first type to the emulation software 302 via the first socket 402. The M43 message of a first type contains information necessary for the emulation software 302 to generate command messages M44 of a second type, intended to be processed by the central gateway 103.

[0053] Thus, in a fourth substep E44, the emulation software 302 processes the content of the first-type command message M43 in order to generate second-type command messages M44 intended for processing by the central gateway 103. Each second-type command message M44 created by the emulation software 302 is structured according to the Diagnostic Over IP protocol; in particular, each message includes: - a source address corresponding to the address of the remote diagnostic system 20, - a destination address corresponding to the address of the computer that will be diagnosed, and - command messages in UDS format, which are generated by the 302 emulation software.

[0054] The second type M44 command messages are transmitted to the central gateway 103 via the second socket 403.

[0055] In a substep E45, the central gateway 103 interprets the second-type command messages M44 and then individually distributes messages from order of a third type M45 respectively to the local diagnostic systems concerned 102.

[0056] Then, the local diagnostic systems 102 receive the third-type M45 command messages from the central gateway 103. The local diagnostic systems 102 then process the UDS commands contained in the third-type command messages and then transmit first-type R45 response messages to the central gateway relating to the received UDS commands. The R45 response messages sent by the local diagnostic systems 102 are then transmitted to the central gateway 103.

[0057] Then, in a sixth substep E46, the central gateway 103 transmits response messages of a second type R46 to the emulation software 302 via the second socket 403. The response messages sent in binary format by the local diagnostic systems 102 are then converted by the emulation software 302 into the final format known to the remote diagnostic system 20, in particular into hexadecimal format. Next, the emulation software 302 transmits, via the first socket 402, to the remote diagnostic system 20 response messages of a third type R461 converted into the final format. The remote diagnostic system 20 is then able to process the R461 responses from the local diagnostic systems 102. The processing applied to the responses from the local diagnostic systems 102 may include displaying the status of a diagnosed subsystem.

[0058] The invention also relates to a method for diagnosing a motor vehicle comprising an implementation of the method for managing communication between the motor vehicle 10 and a diagnostic system 20 according to the invention.

[0059] Overall, the system and method according to the invention make it possible to replace a physical communication interface (VCI) with a virtual communication interface, using a simple OBD-Ethernet cable to connect the computer to the vehicle. The system and method according to the invention make it possible to perform diagnostics by directly transmitting UDS commands from a remote diagnostic system (the remote diagnostic system being installed on a remote computer not part of the vehicle) to a central gateway in the motor vehicle. The central gateway then redirects the UDS commands to the relevant local diagnostic systems. The system according to the invention then receives responses from the local diagnostic systems and transmits them to the remote diagnostic system.

[0060] The system according to the invention has several advantages over systems known in the prior art. Indeed, it allows for a significant reduction in costs and greater simplicity in manufacturing and use.

[0061] Due to the simplicity of manufacture and the low cost of an OBD-Ethernet cable, a system according to the invention can be more readily available within the company for different users.

[0062] Furthermore, by replacing specific hardware with a simple OBD-Ethernet cable and a Python script, the system according to the invention allows for efficient diagnosis while remaining compatible with developments in the automotive industry.

Claims

Demands

1. A method for managing communication between a motor vehicle (10) and a remote diagnostic system (20) of the motor vehicle installed on a computer (30) not forming part of the motor vehicle (10), the motor vehicle comprising: - a first plurality (101) of subsystems, in particular the motor vehicle's control units, - a second plurality (102) of local diagnostic systems, a local diagnostic system being capable of providing a diagnosis of the state of at least one subsystem of the first plurality (101), - a central system (103), referred to as the "central gateway", capable of communicating: (i) on the one hand with each local diagnostic system of the second plurality (102) of local diagnostic systems, and (ii) on the other hand with the remote diagnostic system (20), according to a "diagnostic over IP" communication protocol.the method being characterized in that it comprises: - a step (E1) of connecting an OBD-Ethernet cable between the motor vehicle (10) and the computer (30), comprising connecting one end of the OBD-Ethernet cable comprising an Ethernet connector to a connector on the computer (30), and connecting one end of the cable comprising an OBD connector to a connector on the motor vehicle (10), then - a step (E2) of configuring, in the computer (30), communication means capable of enabling, via the OBD-Ethernet cable, the sending of messages to the central gateway (103) of the motor vehicle and the reception of messages from the central gateway (103) of the motor vehicle (10), then - a step (E3) of establishing communication between the remote diagnostic system (20) and the central gateway (103),by executing on the computer (30) a system (302) emulating steps of the "diagnostic over IP" communication protocol between the remote diagnostic system (20) and the central gateway (103).

2. A management method according to the preceding claim, characterized in that step (E2) of configuring communication means capable of enabling, via the OBD-Ethernet cable (401), the sending of messages to the central gateway (103) of the motor vehicle (10) and the reception of messages from the central gateway (103) of the motor vehicle (10) includes: - the establishment of an Ethernet connection between the computer (30) and the central gateway (103) of the motor vehicle (10), and - the creation of a first TCP socket (402) attached to an IP address and a port associated with the remote diagnostic system (20), and - the creation of a second TCP socket (403) attached to an IP address and a port associated with the central gateway (103).

3. A management method according to any one of the preceding claims, characterized in that the step (E3) of establishing communication between the remote diagnostic system (20) and the central gateway (103) comprises a successive emulation, by an emulation system (302), of messages (M1, M2, M3, M4) intended for the central gateway (103), - a first message (M1) emulating a message identifying the motor vehicle (10), then - a second message (M2) emulating a routing activation message, reception of the second message by the central gateway (103) inducing the creation by the central gateway (103) of a TCP socket attached to an IP address and a port associated with the central gateway (103), then - a third message (M3) emulating a check of the ability of the central gateway (103) to respond to requests from the remote diagnostic system (20),then - a fourth message (M4) emulating a check of the state of the central gateway (103).

4. A management method according to any one of the preceding claims, characterized in that it further comprises, following step (E3) of establishing communication between the remote diagnostic system and the central gateway, a step (E4) of diagnosing at least one subsystem of the first plurality (101) of subsystems, the diagnostic step (E4) comprising: - a first substep (E41) of selecting at least one subsystem of the first plurality (101) to be diagnosed, then - a second sub-step (E42) of determining, for each at least one selected subsystem, one or more diagnostic operations to be carried out, - then, a third sub-step (E43) of transmission by the remote diagnostic system (20) of a command message of a first type (M43) to the emulation software (302) via the first socket (402), the command message of a first type (M43) containing the diagnostic operations to be performed for each at least one subsystem selected from the first plurality (101) of subsystems, - then, a fourth sub-step (E44) comprising: (i) generation by the emulation system (302) of at least one command message of a second type (M44) respectively intended for at least one local diagnostic system (102) associated with the at least one selected subsystem, then (ii) a transmission by the emulation system (302) of at least one command message of a second type (M44) via the second socket (403) to the central gateway (103), - then, a fifth sub-step (E45) comprising: (i) a reception by the central gateway (103), via the second socket (403), of at least one command message of a second type (M44), then (ii) a transmission, via the central gateway (103), of at least one third-type command message (M45) to at least one selected local diagnostic system (102), then (iii) a reception, by at least one selected local diagnostic system (102), of at least one third-type command message (M45), then (iv) a transmission, by at least one selected local diagnostic system (102), of a first-type response message (R45) to the central gateway (103), - then, a sixth sub-stage (E46) comprising: (i) a transmission, by the central gateway (103), via the second socket (403) of a reply message of a second type (R46) to the emulation system (302), (ii) then a transmission by the emulation system (302), via the first socket (402) of a third type response message (R461) to the remote diagnostic system (20).

5. Management method according to the preceding claim, characterized in that each command message of a second type (M44) created by the emulation software (302) is structured in accordance with the Diagnostic Over IP protocol, in particular each command message of a second type (M43) includes: - a message sending address, corresponding to an IP address of the remote diagnostic system (20), - a message destination address, corresponding to an IP address of a subsystem of the first plurality (101) to be diagnosed and - command messages in UDS format, which are generated by the emulation software (302).

6. Management method according to any one of claims 4 or 5, characterized in that a response message of a first type (R45) from at least one selected local diagnostic system (102) and transmitted to the central gateway (103) is coded in binary format, and in that the transmission, by the emulation system (302), of a response message to the remote diagnostic system (20) includes a conversion of the response message of a second type (R46) received by the emulation system (302), into a response message of a third type (R461) in hexadecimal format.

7. Management method according to any one of claims 4 to 6, characterized in that the substep (E41) of selecting at least one subsystem of the first plurality (101) to be diagnosed, and / or the substep (E42) of determining, for each at least one selected subsystem, one or more diagnostic operations to be performed are implemented via a human-machine interface (303) communicating with the remote diagnostic system (20).

8. A method for diagnosing a motor vehicle (10) comprising a step of implementing a method for managing communication between the motor vehicle (10) and a diagnostic system (20) according to any one of the preceding claims.

9. A device (1) for diagnosing a motor vehicle (10), comprising a motor vehicle (10) and a remote diagnostic system (20) for the motor vehicle installed on a computer (30) not forming part of the motor vehicle, characterized in that it includes means for implementing the diagnostic process according to the preceding claim and / or means for implementing the management process according to any one of claims 1 to 7.