Diagnostic protocol search with improved efficiency

Abstract

The invention relates to diagnostic protocol search with improved efficiency. A system and method for efficiently determining diagnostic protocols used by vehicles in a service and suitably instantiating the service. The diagnostic protocol is checked for an expected electrical behavior exhibited at a pin of a diagnostic port of the vehicle. If an expected behavior is observed, a first protocol is designated to be used. If the expected behavior is not observed, other protocols are tested for appropriate designation.

Description

Technical Field

[0001] The present disclosure relates to vehicle diagnostics, and more particularly to utilizing a dedicated tool to perform vehicle diagnostic actions. Background Art

[0002] Modern vehicles utilize computing processors to control various functions of the vehicle. These processors communicate with each other and with external devices via a communication bus, commonly referred to as a diagnostic bus. The vehicle's diagnostic bus can be used to interface with external tools suitable for the user to obtain diagnostic information indicating the operating condition of one or more components of the vehicle.

[0003] However, different vehicles of different makes, models, and years of manufacture may be compatible with different diagnostic languages, referred to as diagnostic protocols. Different diagnostic protocols utilize different communication standards and messages. Interfacing with a diagnostic bus using the wrong diagnostic protocol is not only ineffective, but can also cause additional errors in the operation of components that communicate with the diagnostic bus. Therefore, it is important for a technician performing a diagnostic action or service action to utilize the correct diagnostic protocol when interfacing with the vehicle's diagnostic bus. Determining the appropriate diagnostic protocol for use with a particular vehicle can be a time-consuming process.

[0004] What is desired is a method for determining the specific diagnostic protocol used by the diagnostic bus of any vehicle. The method for determining should be accurate and efficient to provide a technician performing a diagnostic action or a service action with the ability to begin the desired action as quickly as possible. Summary of the invention

[0005] One aspect of the present disclosure is directed to a method for instantiating a vehicle diagnostic action. The method includes establishing electrical contact between a diagnostic tool and a plurality of pins of a diagnostic port of a vehicle. The method further includes monitoring the operating conditions of the plurality of pins of the diagnostic port. A first pin is monitored for a first expected voltage behavior relative to a neutral ground. A second pin is monitored for a second expected voltage behavior relative to the neutral ground. When both the first pin and the second pin exhibit the expected voltage behavior, a first diagnostic protocol is considered to be in use. Otherwise, if at least one of the pins does not exhibit the expected voltage behavior, a different protocol is considered to be in use. In response to this determination, an ordered protocol selection may be initiated to specify a specified protocol from an ordered list of compatible diagnostic protocols. Once a protocol has been determined and designated as an operating protocol, the diagnostic tool may generate a request for vehicle identification data to the vehicle. Once the vehicle identification data has been received, the diagnostic tool may determine the make, model, and year of manufacture of the vehicle to further interpret the diagnostic information provided by the vehicle during the remaining diagnostic action or service action.

[0006] Another aspect of the present disclosure is directed to a method for instantiating a vehicle diagnostic action. The method includes establishing electrical contact between a diagnostic tool and a plurality of pins of a diagnostic port of a vehicle. The method further includes monitoring the operating conditions of the plurality of pins of the diagnostic port. The first pin is monitored for a first expected impedance relative to a neutral ground. The second pin is monitored for a second expected impedance relative to the neutral ground. When both the first pin and the second pin exhibit an expected impedance, it is considered that a first diagnostic protocol is being used. Otherwise, if at least one of the pins does not exhibit an expected voltage behavior, it is considered that a different protocol is being used. In response to this determination, an ordered protocol selection may be initiated to specify a specified protocol from an ordered list of compatible diagnostic protocols. Once a protocol has been determined and designated as an operating protocol, the diagnostic tool may generate a request for vehicle identification data to the vehicle. Once the vehicle identification data has been received, the diagnostic tool may determine the make, model, and year of manufacture of the vehicle to further interpret the diagnostic information provided by the vehicle during the remaining diagnostic action or service action. In some embodiments, the impedance between the pins may be monitored as an additional check before determining whether the first protocol is suitable for use.

[0007] The above aspects and other aspects of the present disclosure will be explained in more detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a diagrammatic representation of the vehicle's diagnostic tools and diagnostic ports.

[0009] Figure 2 is a flow chart illustrating a method for instantiating a diagnostic action for a vehicle.

[0010] Figure 3 is a flow chart illustrating a method for instantiating a diagnostic action for a vehicle.

[0011] Figure 4 is a flow chart illustrating a method for instantiating a diagnostic action for a vehicle. DETAILED DESCRIPTION

[0012] The illustrated embodiments are disclosed with reference to the accompanying drawings. However, it is to be understood that the disclosed embodiments are intended to be merely examples that may be embodied in various and alternative forms. The figures are not necessarily drawn to scale, and some features may be exaggerated or minimized to show details of particular components. The specific structural and functional details disclosed are not to be construed as limiting, but rather as a representative basis for teaching those skilled in the art how to practice the disclosed concepts.

[0013] Figure 1A diagrammatic view of a vehicle 100 presented in service. In the context of this document, "service" is used to describe active changes to vehicle hardware or software (such as from a repair or maintenance action) as well as diagnostic operations used to determine the state of the vehicle. In the depicted embodiment, the vehicle 100 includes a consumer sedan, but the make and model of the vehicle may include any configuration without departing from the teachings disclosed herein. In some such embodiments, the vehicle 100 may include a sedan, a compact car, a light truck, a motorcycle SUV, an SUV, a side-by-side vehicle, a commercial transporter, a bus, a luxury sedan, a sport utility vehicle, a crossover, a full-size van, a minivan, a station wagon, a truck, or any other vehicle without departing from the teachings disclosed herein. In some embodiments, the vehicle 100 may include a boat or an aircraft without departing from the teachings disclosed herein.

[0014] The vehicle 100 includes a diagnostic port 101 having a plurality of pins 103. In the depicted embodiment, the diagnostic port 101 includes a port suitable for connecting using an on-board diagnostic (OBD) protocol, but other embodiments may include other configurations without departing from the teachings disclosed herein. In the depicted embodiment, each pin 103 is capable of receiving or transmitting an electrical signal, including an electrical signal that carries information. In the depicted embodiment, the diagnostic port 101 includes sixteen (16) pins 103, generally labeled as pins 1-16. In this depiction, the top row of pins 103 includes a group of pins 103-1 to 103-8 (pins 1 to 8 are outside the context of these teachings). The bottom row of pins 103 includes a group of pins 103-9 to 103-16 (pins 9 to 16 are outside the context of these teachings). To facilitate understanding of the illustration, pins 103-1, 103-6, 103-8, 103-9, 103-14 and 103-16 have been additionally labeled.

[0015] Vehicle 100 is carried out data communication with diagnostic tool 105 via data connection 107. In the depicted embodiment, diagnostic tool 105 includes special diagnostic processing equipment, but other embodiments may include other configurations without departing from the teaching disclosed herein. In such embodiments, diagnostic tool 105 can be embodied as mobile processing equipment, smart phone, tablet computer, laptop computer, wearable computing device, desktop computer, personal digital assistant (PDA) equipment, handheld processor device, dedicated processor device, processor system distributed on the network, processor system configured with wired or wireless communication, or any other alternative embodiment known to those of ordinary skill in the art. In any such embodiment, diagnostic tool 105 will have to have the mode of docking with diagnostic port 101.

[0016] In the depicted embodiment, data connection 107 comprises a wired electrical connection conforming to the OBD-II protocol standard, but other embodiments may include other connections without departing from the teachings disclosed herein.

[0017] The data connection 107 may include a wired connection (as depicted), or may include a wireless connection. A wired embodiment of the data connection 107 may include a TCP / IP connection, a local area network (LAN) connection, a plain old telephone service (POTS) connection, an Internet Protocol connection, an electrical wiring, a conductive channel, an electrical bus, an optical fiber path, or any other alternative embodiment known to those of ordinary skill in the art. A wireless embodiment of the data connection 107 may include, may be configured to communicate wirelessly via one or more of RF (radio frequency) specifications, cellular telephone channels (analog or digital), cellular data channels, Bluetooth specifications, Wi-Fi specifications, satellite transceiver specifications, infrared transmissions, Zigbee specifications, local area networks (LANs), wireless local area networks (WLANs), or any other alternative configurations, protocols, or standards known to those of ordinary skill in the art.

[0018] The diagnostic tool 105 is advantageously compatible with various diagnostic protocols that may be utilized by the vehicle 100 and the diagnostic port 101. Selecting the appropriate diagnostic protocol is important because sending messages formatted for an inappropriate protocol can produce undesirable results. Communications utilizing an inappropriate diagnostic protocol can result in misinterpreted data, create additional error conditions within the vehicle, and generally slow down service of the vehicle until the appropriate diagnostic protocol is determined and utilized instead.

[0019] Therefore, the process of determining and specifying a diagnostic protocol for use with the vehicle 100 should be accurately performed before any service action or diagnostic action occurs. Intelligent selection of a compatible diagnostic protocol for testing by the diagnostic tool 107 can reduce the time spent determining which protocol to use.

[0020] A very common family of diagnostic protocols in modern vehicles is the Controller Area Network (CAN) protocol. The CAN protocol exists broadly in two categories: "Busy CAN" (sometimes called "Noisy CAN") can be observed using passive observation of the pins of the diagnostic port 101. Busy CAN signals will be passively observable by the diagnostic tool 107 without first sending a request for information. Observation of busy CAN signals can be done by observing coherent data traffic that conforms to the CAN protocol: observing modulation on specific pins 103 that are interpreted by the diagnostic tool 105 as CAN messages, even if no message is requested.

[0021] However, the so-called "Silent CAN" protocol utilizes CAN formatting and messages but exhibits no passively detectable coherent data traffic at the diagnostic port. However, the Silent CAN protocol does exhibit electrically measurable behavior at the pins of the diagnostic port 101 that can be measured without sending a request for information.

[0022] In conventional methods, an ordered list of compatible protocols is checked in a specific order chosen so as not to introduce additional error signals or other complications in the service that may be caused by improperly formatted messages. In such a sequence, the CAN is usually checked near the end of the ordered list due to subtle differences in the messages sent. However, because the CAN protocol is so common, and because even silent CAN protocols exhibit measurable behavior, it is advantageous to perform these measurements to determine if a CAN protocol is present as early as possible in the process to minimize the time spent determining the diagnostic protocol that the diagnostic tool 105 should specify for use.

[0023] The CAN signal can be measured using the voltage or impedance at pins 103-6 and 103-14. Because these measurements do not require interaction between the diagnostic tool 105 and any processor of the vehicle 100, the identity determination of the CAN protocol can occur much faster than call and response checks for other protocols.

[0024] In the depicted embodiment, the voltages of pins 103-6 (pin 6) and 103-14 (pin 14) may be checked in comparison to the neutral ground of the pins. If both pins 103-6 and 103-14 exhibit expected voltage behavior, then it may be assumed that the vehicle 100 utilizes the CAN protocol.

[0025] In the depicted embodiment, the CAN signal will exhibit a dynamic voltage signal on pins 103-6 and 103-14, whose peak value varies between 0V and 5V relative to ground. The signal should also have an average peak value between 0V and 5V, and in the depicted embodiment, the signal will exhibit an average peak value of 2.5V. Some tolerances, such as a 10% difference from the average peak value, may also be exhibited without departing from the teachings disclosed herein. If each of pins 103-6 and 103-14 exhibits the expected voltage signal, it can be inferred that the vehicle 100 utilizes the CAN protocol and the diagnostic tool 105 can instantiate a service function.

[0026] Although in the depicted embodiment, measurements are performed on pins 103-6 and 103-14, other embodiments may utilize other pins or additional pins to address different "busy" protocols without departing from the teachings disclosed herein. Although in the depicted embodiment, each of pins 103-6 and 103-14 is measured to test the same expected voltage behavior, other embodiments may utilize different expected voltage behaviors for one or more of the tested pins without departing from the teachings disclosed herein.

[0027] Alternatively, the diagnostic tool 105 may measure the impedance of pins 103-6 and 103-14 to evaluate the CAN signal. In the depicted embodiment, if pins 103-6 and 103-14 each exhibit an expected impedance relative to ground, it may be inferred that the vehicle 100 utilizes the CAN protocol.

[0028] In the depicted embodiment, the CAN signal will exhibit an impedance value of between 50 ohms and 70 ohms relative to ground on pins 103-6 and 103-14. In this depicted embodiment, the expected impedance of each pin is an expected impedance value of 60 ohms relative to ground. Some tolerances, such as a 10% difference in impedance value, may be exhibited otherwise without departing from the teachings disclosed herein. If each of pins 103-6 and 103-14 exhibits the expected impedance relative to ground, it can be inferred that the vehicle 100 utilizes the CAN protocol and the diagnostic tool 105 can instantiate a service function.

[0029] Although in the depicted embodiment, measurements are performed on pins 103-6 and 103-14, other embodiments may utilize other pins or additional pins to address different "busy" protocols without departing from the teachings disclosed herein. Although in the described embodiment, each of pins 103-6 and 103-14 is measured to test the same expected impedance, other embodiments may utilize different expected impedances for one or more of the tested pins without departing from the teachings disclosed herein.

[0030] In another alternative measurement, the CAN protocol will exhibit an expected impedance between pins 103-6 and 103-14. The diagnostic tool 105 can measure the impedance across the two pins, and if the measurement exhibits the expected impedance, it can be inferred that the pins are using the CAN protocol. In the depicted embodiment, the expected impedance across the pins is in the range of 100 ohms and 140 ohms. The nominal expected impedance across the pins is 120 ohms, although some tolerances, such as a 10% difference from the impedance value, may otherwise be exhibited without departing from the teachings disclosed herein.

[0031] Although in the depicted embodiment, measurements are performed across pins 103 - 6 and 103 - 14 , other embodiments may utilize other pins or additional pins to address different diagnostic protocols without departing from the teachings disclosed herein.

[0032] In some embodiments, the diagnostic tool 105 can measure voltage and impedance to ensure accuracy in determining the CAN protocol without departing from the teachings disclosed herein. In such embodiments, because each electrical measurement is much faster than the call and response cycles of other known diagnostic protocols, it is still advantageously faster to quickly determine the CAN protocol on average because the most desired protocol is the CAN protocol.

[0033] In the depicted embodiment, if the CAN protocol is not discerned via electrical measurements, the diagnostic tool 105 instead initiates an ordered protocol selection to determine a specified protocol for use with the vehicle 100. The ordered protocol selection relies on an ordered list of compatible diagnostic protocols that are compatible with the diagnostic tool 105. In the depicted embodiment, the diagnostic tool 105 is compatible with the CAN protocol, but is also compatible with additional protocols. Additional protocols include ISO 9141, ISO 14230, J1850 VPW, or J1850 PWM. Without departing from the teachings disclosed herein, other embodiments may utilize different protocol lists with additional or different protocol compatibilities. Without departing from the teachings disclosed herein, the ordered list of compatible diagnostic protocols may be sorted in any order.

[0034] Once the diagnostic protocol utilized by the vehicle 100 is determined, service can begin. In the depicted embodiment, the first step in service is the instantiation of vehicle identification data, such as a vehicle identification number (VIN), used to describe the vehicle 100. The diagnostic tool 105 requests the vehicle identification data from the vehicle 100 via the diagnostic port 101. In the depicted embodiment, the diagnostic tool 105 can determine the exact make, model, and year of manufacture of the vehicle 100 based on the vehicle identification data, either in a lookup function of the internal memory (not shown) of the diagnostic tool 105 or by consulting an external database (not shown). Once the make, model, and year of manufacture of the vehicle 100 are determined along with the diagnostic protocol, the diagnostic tool 105 has enough information to easily interpret all diagnostic messages generated by the vehicle 100 during service.

[0035] Figure 2 is a diagram of a vehicle (such as vehicle 100; see Figure 1 ) and diagnostic tools (such as diagnostic tool 105; see Figure 1 ) between a plurality of devices.

[0036] The method begins at step 200 where a diagnostic tool and a diagnostic port (such as diagnostic port 101; see Figure 1 ) establish an electrical connection between. In the depicted embodiment, the diagnostic port includes a port that complies with the on-board diagnostic type II protocol (OBD-II), and other embodiments may include other diagnostic port configurations without departing from the teachings disclosed herein.

[0037] After electrical contact is established, at step 202, the diagnostic port is passively observed for messages that conform to the first protocol. In the depicted embodiment, the first protocol is the CAN protocol, but other embodiments may utilize other first protocols without departing from the teachings disclosed herein. In the depicted embodiment, the diagnostic port is observed for a predetermined amount of time, which defines a predetermined observation window. The predetermined observation window may advantageously be selected to conform to the message transmission and reception frequency of the first diagnostic protocol, or a multiple thereof. If messages are observed, the first diagnostic protocol may be specified for use by the diagnostic tool (see step 208). Otherwise, the method proceeds to step 204 to check the first protocol using electrical measurements.

[0038] At step 204, multiple pins of the diagnostic port are monitored for expected voltage behavior. In the depicted embodiment, 2 pins are monitored using two sub-steps 204a and 204b, but other embodiments may include a different number of sub-steps without departing from the teachings disclosed herein. In the depicted embodiment, sub-step 204a measures pin 6 of the diagnostic port, and sub-step 204b measures pin 14 of the diagnostic port, but other embodiments may include different or additional pins without departing from the teachings disclosed herein.

[0039] In the depicted embodiment, sub-steps 204a and 204b occur at least partially simultaneously, but other embodiments may process their sub-steps in any order, partially simultaneously, or fully simultaneously without departing from the teachings disclosed herein.

[0040] In the depicted embodiment, pin 6 and pin 14 are monitored for the expected voltage of the CAN signal relative to ground. The CAN signal will exhibit a dynamic voltage signal on pin 6 and pin 14 with a peak value varying between 0V and 5V relative to ground. The monitored signal should additionally have an average peak value between 0V and 5V, and in the depicted embodiment should exhibit an average peak value of 2.5V. Some tolerances, such as a 10% difference from the average peak value, may additionally be exhibited without departing from the teachings disclosed herein.

[0041] At step 206, if each of pin 6 and pin 14 exhibits the expected voltage signal behavior, the diagnostic port is considered to utilize the CAN protocol, and this protocol is designated as the protocol to be used at step 208. If one or both pins do not exhibit the expected voltage behavior, the CAN protocol cannot be inferred, but instead the method continues to step 210, where the next protocol from the ordered list of compatible protocols is tested instead. In the depicted embodiment, the ordered list of compatible protocols may include ISO 9141, ISO 14230, J1850 VPW, or J1850 PWM. Without departing from the teachings disclosed herein, other embodiments may include different protocol combinations with different or additional protocols. Without departing from the teachings disclosed herein, other embodiments may include different orders within the ordered list of protocols.

[0042] If the next protocol is not confirmed as the correct protocol to be used at step 212, the method proceeds to step 214 where it is determined whether the ordered list of compatible protocols has been exhausted. If the list has been exhausted, the method ends at step 216 because the vehicle in service does not utilize a diagnostic protocol that is compatible with the diagnostic tool. However, if the ordered list has not been exhausted, the method instead returns to step 210 where the next protocol in the ordered list is tested.

[0043] When a compatible protocol is found and confirmed to be suitable for use with the vehicle at step 212 , the method proceeds to step 218 where the protocol is designated for use in service.

[0044] Once a protocol is specified for use (either utilizing the CAN protocol at step 208 or utilizing one of the compatible protocols from an ordered list at step 218), the method proceeds to step 220 to request vehicle identification data from the vehicle in service. In the depicted embodiment, the vehicle identification data includes a vehicle identification number (VIN), but other embodiments may utilize different or additional data for vehicle identification purposes without departing from the teachings disclosed herein. After receipt of the vehicle identification data from the vehicle, at step 222, the vehicle is identified by the make, model, and year of manufacture of the vehicle. Once the diagnostic protocol, make, model, and year of manufacture are identified, the service has been appropriately instantiated and different methods for service actions or diagnostic actions can be performed.

[0045] Figure 3 is a diagram of a vehicle (such as vehicle 100; see Figure 1 ) and diagnostic tools (such as diagnostic tool 105; see Figure 1) between a plurality of devices.

[0046] The method begins at step 300, where a diagnostic tool and a diagnostic port (such as diagnostic port 101; see Figure 1 ) between the electrical contacts. In the depicted embodiment, the diagnostic port includes a port that complies with the On-Board Diagnostics Type II protocol (OBD-II), other embodiments may include other diagnostic port configurations without departing from the teachings disclosed herein.

[0047] After establishing electrical contact, the diagnostic port is passively observed for messages conforming to the first protocol at step 302. In the depicted embodiment, the first protocol is the CAN protocol, but other embodiments may utilize other first protocols without departing from the teachings disclosed herein. In the depicted embodiment, the diagnostic port is observed for a predetermined amount of time, which defines a predetermined observation window. The predetermined observation window may advantageously be selected to conform to the message transmission and reception frequency of the first diagnostic protocol, or a multiple thereof. If messages are observed, the first diagnostic protocol may be specified for use by the diagnostic tool (see step 308). Otherwise, the method proceeds to step 304 to check the first protocol using electrical measurements.

[0048] At step 304, a plurality of pins of the diagnostic port are monitored for expected impedance values. In the depicted embodiment, two sub-steps 304a and 304b are utilized to monitor 2 pins, but other embodiments may include a different number of sub-steps without departing from the teachings disclosed herein. In the depicted embodiment, sub-step 304a measures the impedance of pin 6 of the diagnostic port relative to ground, and sub-step 304b measures the impedance of pin 14 of the diagnostic port relative to ground. Other embodiments may include different or additional pins without departing from the teachings disclosed herein.

[0049] In the depicted embodiment, sub-steps 304a and 304b occur at least partially simultaneously, but other embodiments may process their sub-steps in any order, partially simultaneously, or fully simultaneously without departing from the teachings disclosed herein.

[0050] In the depicted embodiment, pin 6 and pin 14 are monitored for an expected impedance relative to ground that is measured in accordance with the CAN protocol. The CAN protocol will present an impedance of 50-70 ohms relative to ground on each of pin 6 and pin 14. In the depicted embodiment, each of pin 6 and pin 14 is expected to present an impedance of 60 ohms relative to ground. Some tolerances may additionally be presented, such as a 10% difference in impedance, without departing from the teachings disclosed herein.

[0051] At step 306, if each of pin 6 and pin 14 exhibits the expected impedance, the diagnostic port is considered to utilize the CAN protocol, and this protocol is designated as the protocol to be used at step 308. If one or both pins do not exhibit the expected impedance, a busy CAN protocol cannot be inferred, but instead the method continues to step 310, where the next protocol from the ordered list of compatible protocols is tested instead. In the depicted embodiment, the ordered list of compatible protocols may include Quiet CAN, ISO 9141, ISO 14230, J1850 VPW, or J1850 PWM. Without departing from the teachings disclosed herein, other embodiments may include different protocol combinations with different or additional protocols. Without departing from the teachings disclosed herein, other embodiments may include different orders within the ordered list of protocols.

[0052] If the next protocol is not confirmed as the correct protocol to be used at step 312, the method proceeds to step 314 where it is determined whether the ordered list of compatible protocols has been exhausted. If the list has been exhausted, the method ends at step 316 because the vehicle in service does not utilize a diagnostic protocol that is compatible with the diagnostic tool. However, if the ordered list has not been exhausted, the method instead returns to step 310 where the next protocol in the ordered list is tested.

[0053] When a compatible protocol is found and confirmed to be suitable for use with the vehicle at step 312 , the method proceeds to step 318 where the protocol is designated for use in service.

[0054] Once a protocol is specified for use (either utilizing the CAN protocol at step 308 or utilizing one of the compatible protocols from an ordered list at step 318), the method proceeds to step 320 to request vehicle identification data from the vehicle in service. In the depicted embodiment, the vehicle identification data includes a vehicle identification number (VIN), but other embodiments may utilize different or additional data for vehicle identification purposes without departing from the teachings disclosed herein. After receipt of the vehicle identification data from the vehicle, at step 322, the vehicle is identified by the make, model, and year of manufacture of the vehicle. Once the diagnostic protocol, make, model, and year of manufacture are identified, the service has been appropriately instantiated and different methods for service actions or diagnostic actions can be performed.

[0055] Figure 4 is a diagram of a vehicle (such as vehicle 100; see Figure 1 ) and diagnostic tools (such as diagnostic tool 105; see Figure 1) between a plurality of devices.

[0056] The method begins at step 400, where a diagnostic tool and a diagnostic port (such as diagnostic port 101; see Figure 1 ) between the electrical contacts. In the depicted embodiment, the diagnostic port includes a port that complies with the On-Board Diagnostics Type II protocol (OBD-II), other embodiments may include other diagnostic port configurations without departing from the teachings disclosed herein.

[0057] After establishing electrical contact, the diagnostic port is passively observed for messages conforming to the first protocol at step 402. In the depicted embodiment, the first protocol is the CAN protocol, but other embodiments may utilize other first protocols without departing from the teachings disclosed herein. In the depicted embodiment, the diagnostic port is observed for a predetermined amount of time, which defines a predetermined observation window. The predetermined observation window may advantageously be selected to conform to the message transmission and reception frequency of the first diagnostic protocol, or a multiple thereof. If messages are observed, the first diagnostic protocol may be specified for use by the diagnostic tool (see step 408). Otherwise, the method proceeds to step 404 to check the first protocol using electrical measurements.

[0058] At step 404, multiple pins of the diagnostic port are monitored for expected impedance values. In the depicted embodiment, three sub-steps 404a, 404b, and 404c are utilized to monitor 2 pins, but other embodiments may include a different number of sub-steps without departing from the teachings disclosed herein. In the depicted embodiment, sub-step 404a measures the impedance of pin 6 of the diagnostic port relative to ground, and sub-step 404b measures the impedance of pin 14 of the diagnostic port relative to ground. Sub-step 404c measures the impedance across pin 6 and pin 14 as electrical terminals. Other embodiments may include different or additional pins without departing from the teachings disclosed herein.

[0059] In the depicted embodiment, sub-steps 404a and 404b occur at least partially simultaneously, and sub-step 404c occurs after each other sub-step has been completed. Other embodiments may process their sub-steps in any order, partially simultaneously, or completely simultaneously without departing from the teachings disclosed herein.

[0060] In the depicted embodiment, pin 6 and pin 14 are monitored for an expected impedance relative to ground for a CAN signal. The CAN signal will exhibit an impedance of 50-70 ohms relative to ground on each of pin 6 and pin 14. In the depicted embodiment, each of pin 6 and pin 14 is expected to exhibit an impedance of 60 ohms relative to ground. Some tolerances, such as a 10% difference in impedance, may otherwise be exhibited without departing from the teachings disclosed herein.

[0061] The impedance across pin 6 and pin 14 is additionally monitored for expected impedance. The CAN protocol will present an impedance of 100-140 ohms between pin 6 and pin 14. In the depicted embodiment, the expected impedance between pin 6 and pin 14 is 120 ohms. Some tolerance, such as a 10% difference in impedance, may additionally be presented without departing from the teachings disclosed herein.

[0062] At step 406, if each of pin 6 and pin 14 exhibits the expected impedance in its respective sub-step of step 404, then the diagnostic port is deemed to utilize the CAN protocol, and this protocol is designated as the protocol to be used at step 408. If one or both pins do not exhibit the expected impedance, then the CAN protocol cannot be inferred, but instead the method continues to step 410 where the next protocol from the ordered list of compatible protocols is tested instead. In the depicted embodiment, the ordered list of compatible protocols may include ISO 9141, ISO 14230, J1850 VPW, or J1850 PWM. Without departing from the teachings disclosed herein, other embodiments may include different protocol combinations with different or additional protocols. Without departing from the teachings disclosed herein, other embodiments may include different orders within the ordered list of protocols.

[0063] If the next protocol is not confirmed as the correct protocol to be used at step 412, the method proceeds to step 414 where it is determined whether the ordered list of compatible protocols has been exhausted. If the list has been exhausted, the method ends at step 416 because the vehicle in service does not utilize a diagnostic protocol that is compatible with the diagnostic tool. However, if the ordered list has not been exhausted, the method instead returns to step 410 where the next protocol in the ordered list is tested.

[0064] When a compatible protocol is found and confirmed to be suitable for use with the vehicle at step 412 , the method proceeds to step 418 where the protocol is designated for use in service.

[0065] Once a protocol is specified for use (either utilizing the CAN protocol at step 408 or utilizing one of the compatible protocols from an ordered list at step 418), the method proceeds to step 420 to request vehicle identification data from the vehicle in service. In the depicted embodiment, the vehicle identification data includes a vehicle identification number (VIN), but other embodiments may utilize different or additional data for vehicle identification purposes without departing from the teachings disclosed herein. After receipt of the vehicle identification data from the vehicle, at step 422, the vehicle is identified by the make, model, and year of manufacture of the vehicle. Once the diagnostic protocol, make, model, and year of manufacture are identified, the service has been appropriately instantiated and different methods for service actions or diagnostic actions can be performed.

[0066] Although exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the disclosed apparatus and methods. Instead, the words used in the specification are descriptive rather than restrictive, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure claimed. The features of various implementing embodiments may be combined to form further embodiments of the disclosed concepts.

Claims

1. A method for instantiating a vehicle diagnostic action, the method comprising: establishing electrical contact between a plurality of pins of a diagnostic tool and a diagnostic port of a vehicle; monitoring the first pin and the second pin for messages conforming to a first diagnostic protocol; In response to receiving a message conforming to the first diagnostic protocol within a predefined observation window, designating the first diagnostic protocol as a designated protocol for use by the diagnostic tool; In response to not receiving a message that complies with the first diagnostic protocol within the predefined observation window, monitoring the first pin for a first expected voltage behavior relative to neutral ground; monitoring a second pin for a second expected voltage behavior relative to the neutral ground, responsive to both the first pin exhibiting the first expected voltage behavior and the second pin exhibiting the second expected voltage behavior, designating the first diagnostic protocol as the designated protocol, In response to the first pin not exhibiting the first expected voltage behavior or the second pin not exhibiting the second expected voltage behavior, initiating ordered protocol selection to specify the specified protocol from an ordered list of compatible diagnostic protocols; sending a request for vehicle identification data from the diagnostic tool to the diagnostic port in the specified protocol; as well as In response to receiving the vehicle identification data from the diagnostic port, a make and model of the vehicle is generated.

2. The method according to claim 1, wherein: The diagnostic port comprises an on-board diagnostic (OBD) port, the first pin is pin 6 of the OBD port, and the second pin is pin 14 of the OBD port.

3. The method according to claim 1, wherein: The first diagnostic protocol is a Controller Area Network (CAN) protocol.

4. The method according to claim 3, wherein: The ordered list of compatible diagnostic protocols further includes an ISO9141 protocol, an ISO 14230 protocol, a J1850 VPW protocol, or a J1850 PWM protocol.

5. The method according to claim 3, wherein: The first expected voltage behavior is a dynamic voltage with an average peak value between 0V and 5V, and the second expected voltage behavior is a dynamic voltage with an average peak value between 0V and 5V.

6. The method according to claim 5, wherein: The first expected voltage behavior is a dynamic voltage with an average peak value of 2.5V, and the second expected voltage behavior is a dynamic voltage with an average peak value of 2.5V. 7 . The method of claim 1 , wherein the first expected voltage behavior is a dynamic voltage with an average peak value between 0V and 5V, and the second expected voltage behavior is a dynamic voltage with an average peak value between 0V and 5V.

8. The method according to claim 7, wherein: The first expected voltage behavior is a dynamic voltage with an average peak value of 2.5V, and the second expected voltage behavior is a dynamic voltage with an average peak value of 2.5V.

9. The method according to claim 1, wherein: The vehicle identification data includes a vehicle identification number (VIN).

10. A method for instantiating a vehicle diagnostic action, the method comprising: establishing electrical contact between a plurality of pins of a diagnostic tool and a diagnostic port of a vehicle; monitoring the first pin and the second pin for messages conforming to a first diagnostic protocol; In response to receiving a message conforming to the first diagnostic protocol within a predefined observation window, designating the first diagnostic protocol as a designated protocol for use by the diagnostic tool; In response to not receiving a message that complies with the first diagnostic protocol within the predefined observation window, measuring a first impedance seen by the diagnostic tool between the first pin and neutral ground, measuring a second impedance seen by the diagnostic tool between the second pin and neutral ground, comparing the first impedance and the second impedance to expected impedances, in response to both the first impedance and the second impedance exhibiting the expected impedance, designating a first diagnostic protocol as the designated protocol, in response to one of the first impedance or the second impedance not exhibiting the expected impedance, initiating ordered protocol selection to specify the designated protocol from an ordered list of compatible diagnostic protocols; sending a request for vehicle identification data from the diagnostic tool to the diagnostic port in the specified protocol; as well as In response to receiving the vehicle identification data from the diagnostic port, a make and model of the vehicle is generated.

11. The method according to claim 10, wherein: The expected impedance is between 50 ohms and 70 ohms.

12. The method according to claim 11, wherein: The expected impedance is 60 ohms.

13. The method according to claim 10, wherein: The expected impedance is a first expected impedance, and the method further comprises the steps of: measuring a third impedance seen by the diagnostic tool between the first pin and the second pin; comparing the third impedance to a second expected impedance; designating the first diagnostic protocol used by the diagnostic tool as the designated protocol in response to the first impedance exhibiting the first expected impedance, the second impedance exhibiting the first expected impedance, and the third impedance exhibiting the second expected impedance; and In response to one of the first impedance not exhibiting the first expected impedance, the second impedance not exhibiting the first expected impedance, or the third impedance not exhibiting the second expected impedance, the ordered protocol selection is initiated to specify the specified protocol from the ordered list of compatible diagnostic protocols.

14. The method according to claim 13, wherein: The second desired impedance is between 100 ohms and 140 ohms.

15. The method according to claim 14, wherein: The second expected impedance is 120 ohms.

16. The method according to claim 10, wherein: The diagnostic port comprises an on-board diagnostic (OBD) port, the first pin is pin 6 of the OBD port, and the second pin is pin 14 of the OBD port.

17. The method according to claim 10, wherein: The first diagnostic protocol is a Controller Area Network (CAN) protocol.

18. The method according to claim 17, wherein: The ordered list of compatible diagnostic protocols further includes an ISO9141 protocol, an ISO 14230 protocol, a J1850 VPW protocol, or a J1850 PWM protocol.

19. A method for selecting a diagnostic protocol to be used by a diagnostic tool during a diagnostic activity of a vehicle, the method comprising: establishing electrical contact between the diagnostic tool and a plurality of pins of a diagnostic port of the vehicle; monitoring a first pin and a second pin for messages conforming to a controller area network (CAN) protocol; In response to receiving a message conforming to the CAN protocol within a predefined observation window, designating the CAN protocol as a designated protocol for use by the diagnostic tool; and In response to not receiving a message conforming to the CAN protocol within the predefined observation window, monitoring the first pin for a first expected voltage behavior relative to neutral ground; monitoring a second pin for a second expected voltage behavior relative to the neutral ground, In response to both the first pin exhibiting the first expected voltage behavior and the second pin exhibiting the second expected voltage behavior, designating the CAN protocol as the designated protocol, In response to the first pin not exhibiting the first expected voltage behavior or the second pin not exhibiting the second expected voltage behavior, initiating ordered protocol selection to specify the specified protocol from an ordered list of compatible diagnostic protocols; in, The ordered protocol selection includes testing each of the ordered list of compatible diagnostic protocols until a compatible diagnostic protocol is found to be used by the diagnostic port.

20. The method according to claim 19, wherein: The ordered list of compatible diagnostic protocols includes, wherein the ordered list of compatible diagnostic protocols further includes the ISO 9141 protocol, the ISO 14230 protocol, the J1850 VPW protocol, or the J1850 PWM protocol.

Images