MANAGING DIAGNOSTIC TROUBLE CODES IN A VEHICLE

A method of managing diagnostic trouble codes (DTCs) in a vehicle includes generating at a vehicle a plurality of DTCs output from one or more diagnostic subtasks; assigning an ordinal number to each DTC independent of time based on the order in which the DTC occurred at the vehicle; and wirelessly transmitting to a central facility the plurality of DTCs along with the ordinal numbers assigned to each DTC.

TECHNICAL FIELD

The present invention relates to vehicle diagnostics and more particularly to managing diagnostic trouble codes (DTCs) in a vehicle.

BACKGROUND

Modern vehicles include on-board systems that can monitor vehicle performance and diagnose problems with vehicle performance when necessary. These on-board systems can be carried out using devices having computer processing capability, such as a vehicle telematics unit, that receive vehicle data from one or more vehicle sensors and monitor vehicle performance. Using the received vehicle data, the on-board systems can determine that the performance of the vehicle is sub-optimal and output a diagnostic trouble code (DTC) that reflects this sub-optimal performance. Some vehicle conditions can cause the on-board system to generate a plurality of DTCs that collectively reflect what is happening at the vehicle.

When the vehicle generates the plurality of DTCs, it can be helpful for diagnosis purposes to know which DTC occurred first, second, third, etc. It is possible to use a clock that is located on the vehicle to determine when the vehicle generates each DTC. However, using a clock is challenging because it requires the presence of a clock, reliance on the accuracy of the clock, and the communication infrastructure needed to access the clock signal.

SUMMARY

According to an embodiment of the invention, there is provided a method of managing diagnostic trouble codes (DTCs) in a vehicle. The steps include generating at a vehicle a plurality of DTCs output from one or more diagnostic subtasks; assigning an ordinal number to each DTC independent of time based on the order in which the DTC occurred at the vehicle; and wirelessly transmitting to a central facility the plurality of DTCs along with the ordinal numbers assigned to each DTC.

According to another embodiment of the invention, there is provided a method of managing diagnostic trouble codes (DTCs) in a vehicle. The steps include generating at a vehicle a plurality of DTCs output from one or more diagnostic subtasks; storing each DTC of the plurality of DTCs at the vehicle along with a condition that caused each DTC; assigning an ordinal number that is independent of time to each stored DTC and condition; and wirelessly transmitting to a central facility the plurality of DTCs and their corresponding conditions along with the assigned ordinal numbers.

According to yet another embodiment of the invention, there is provided a system of managing diagnostic trouble codes (DTCs) in a vehicle. The system includes a vehicle telematics unit comprising a processor, computer-readable memory, and an antenna, wherein the vehicle telematics unit: receives vehicle operational data from one or more vehicle sensor modules; generates a plurality of DTCs that are output from one or more diagnostic subtasks carried out using the processor; assigns an ordinal number to each DTC independent of time based on the order in which the DTC occurred; and wirelessly transmits to a central facility the plurality of DTCs along with the ordinal number assigned to each DTC via the antenna.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT(S)

The method and system described below manages DTCs or other unit of diagnostic output in a vehicle by assigning an ordinal number to each DTC that is unrelated to time. A different ordinal number can be assigned or linked with each DTC of a plurality of DTCs. By using an ordinal number with each DTC, later analysis can reveal the order in which each DTC occurred and do so without attributing a time value to each DTC that is obtained from a clock. Given that the ordinal number can reveal the numerical order in which each DTC occurred, the use of such numbers can remove the use of a clock to record a time that each DTC occurred.

With reference toFIG. 1, there is shown an operating environment that comprises a mobile vehicle communications system10and that can be used to implement the method disclosed herein. Communications system10generally includes a vehicle12, one or more wireless carrier systems14, a land communications network16, a computer18, and a call center20. It should be understood that the disclosed method can be used with any number of different systems and is not specifically limited to the operating environment shown here. Also, the architecture, construction, setup, and operation of the system10and its individual components are generally known in the art. Thus, the following paragraphs simply provide a brief overview of one such communications system10; however, other systems not shown here could employ the disclosed method as well.

Vehicle12is depicted in the illustrated embodiment as a passenger car, but it should be appreciated that any other vehicle including motorcycles, trucks, sports utility vehicles (SUVs), recreational vehicles (RVs), marine vessels, aircraft, etc., can also be used. Some of the vehicle electronics28is shown generally inFIG. 1and includes a telematics unit30, a microphone32, one or more pushbuttons or other control inputs34, an audio system36, a visual display38, and a GPS module40as well as a number of vehicle system modules (VSMs)42. Some of these devices can be connected directly to the telematics unit such as, for example, the microphone32and pushbutton(s)34, whereas others are indirectly connected using one or more network connections, such as a communications bus44or an entertainment bus46. Examples of suitable network connections include a controller area network (CAN), a media oriented system transfer (MOST), a local interconnection network (LIN), a local area network (LAN), and other appropriate connections such as Ethernet or others that conform with known ISO, SAE and IEEE standards and specifications, to name but a few.

According to one embodiment, telematics unit30utilizes cellular communication according to either GSM or CDMA standards and thus includes a standard cellular chipset50for voice communications like hands-free calling, a wireless modem for data transmission, an electronic processing device52, one or more digital memory devices54, and a dual antenna56. It should be appreciated that the modem can either be implemented through software that is stored in the telematics unit and is executed by processor52, or it can be a separate hardware component located internal or external to telematics unit30. The modem can operate using any number of different standards or protocols such as EVDO, CDMA, GPRS, and EDGE. Wireless networking between the vehicle and other networked devices can also be carried out using telematics unit30. For this purpose, telematics unit30can be configured to communicate wirelessly according to one or more wireless protocols, such as any of the IEEE 802.11 protocols, WiMAX, or Bluetooth. When used for packet-switched data communication such as TCP/IP, the telematics unit can be configured with a static IP address or can set up to automatically receive an assigned IP address from another device on the network such as a router or from a network address server.

Apart from the audio system36and GPS module40, the vehicle12can include other vehicle system modules (VSMs)42in the form of electronic hardware components that are located throughout the vehicle and typically receive input from one or more sensors and use the sensed input to perform diagnostic, monitoring, control, reporting and/or other functions. Each of the VSMs42is preferably connected by communications bus44to the other VSMs, as well as to the telematics unit30, and can be programmed to run vehicle system and subsystem diagnostic tests. As examples, one VSM42can be an engine control module (ECM) that controls various aspects of engine operation such as fuel ignition and ignition timing, another VSM42can be a powertrain control module that regulates operation of one or more components of the vehicle powertrain, and another VSM42can be a body control module that governs various electrical components located throughout the vehicle, like the vehicle's power door locks and headlights. According to one embodiment, the engine control module is equipped with on-board diagnostic (OBD) features that provide myriad real-time data, such as that received from various sensors including vehicle emissions sensors, and provide a standardized series of diagnostic trouble codes (DTCs) that allow a technician to rapidly identify and remedy malfunctions within the vehicle. As is appreciated by those skilled in the art, the above-mentioned VSMs are only examples of some of the modules that may be used in vehicle12, as numerous others are also possible.

Vehicle electronics28also includes a number of vehicle user interfaces that provide vehicle occupants with a means of providing and/or receiving information, including microphone32, pushbuttons(s)34, audio system36, and visual display38. As used herein, the term ‘vehicle user interface’ broadly includes any suitable form of electronic device, including both hardware and software components, which is located on the vehicle and enables a vehicle user to communicate with or through a component of the vehicle. Microphone32provides audio input to the telematics unit to enable the driver or other occupant to provide voice commands and carry out hands-free calling via the wireless carrier system14. For this purpose, it can be connected to an on-board automated voice processing unit utilizing human-machine interface (HMI) technology known in the art. The pushbutton(s)34allow manual user input into the telematics unit30to initiate wireless telephone calls and provide other data, response, or control input. Separate pushbuttons can be used for initiating emergency calls versus regular service assistance calls to the call center20. Audio system36provides audio output to a vehicle occupant and can be a dedicated, stand-alone system or part of the primary vehicle audio system. According to the particular embodiment shown here, audio system36is operatively coupled to both vehicle bus44and entertainment bus46and can provide AM, FM and satellite radio, CD, DVD and other multimedia functionality. This functionality can be provided in conjunction with or independent of the infotainment module described above. Visual display38is preferably a graphics display, such as a touch screen on the instrument panel or a heads-up display reflected off of the windshield, and can be used to provide a multitude of input and output functions. Various other vehicle user interfaces can also be utilized, as the interfaces ofFIG. 1are only an example of one particular implementation.

Wireless carrier system14is preferably a cellular telephone system that includes a plurality of cell towers70(only one shown), one or more mobile switching centers (MSCs)72, as well as any other networking components required to connect wireless carrier system14with land network16. Each cell tower70includes sending and receiving antennas and a base station, with the base stations from different cell towers being connected to the MSC72either directly or via intermediary equipment such as a base station controller. Cellular system14can implement any suitable communications technology, including for example, analog technologies such as AMPS, or the newer digital technologies such as CDMA (e.g., CDMA2000) or GSM/GPRS. As will be appreciated by those skilled in the art, various cell tower/base station/MSC arrangements are possible and could be used with wireless system14. For instance, the base station and cell tower could be co-located at the same site or they could be remotely located from one another, each base station could be responsible for a single cell tower or a single base station could service various cell towers, and various base stations could be coupled to a single MSC, to name but a few of the possible arrangements.

Computer18can be one of a number of computers accessible via a private or public network such as the Internet. Each such computer18can be used for one or more purposes, such as a web server accessible by the vehicle via telematics unit30and wireless carrier14. Other such accessible computers18can be, for example: a service center computer where diagnostic information and other vehicle data can be uploaded from the vehicle via the telematics unit30; a client computer used by the vehicle owner or other subscriber for such purposes as accessing or receiving vehicle data or to setting up or configuring subscriber preferences or controlling vehicle functions; or a third party repository to or from which vehicle data or other information is provided, whether by communicating with the vehicle12or call center20, or both. A computer18can also be used for providing Internet connectivity such as DNS services or as a network address server that uses DHCP or other suitable protocol to assign an IP address to the vehicle12.

Call center20is designed to provide the vehicle electronics28with a number of different system back-end functions and, according to the exemplary embodiment shown here, generally includes one or more switches80, servers82, databases84, live advisors86, as well as an automated voice response system (VRS)88, all of which are known in the art. These various call center components are preferably coupled to one another via a wired or wireless local area network90. Switch80, which can be a private branch exchange (PBX) switch, routes incoming signals so that voice transmissions are usually sent to either the live adviser86by regular phone or to the automated voice response system88using VoIP. The live advisor phone can also use VoIP as indicated by the broken line inFIG. 1. VoIP and other data communication through the switch80is implemented via a modem (not shown) connected between the switch80and network90. Data transmissions are passed via the modem to server82and/or database84. Database84can store account information such as subscriber authentication information, vehicle identifiers, profile records, behavioral patterns, and other pertinent subscriber information. Data transmissions may also be conducted by wireless systems, such as 802.11x, GPRS, and the like. Although the illustrated embodiment has been described as it would be used in conjunction with a manned call center20using live advisor86, it will be appreciated that the call center can instead utilize VRS88as an automated advisor or, a combination of VRS88and the live advisor86can be used.

Turning now toFIG. 2, there is shown an embodiment of a method200of managing diagnostic trouble codes (DTCs) in the vehicle12. The method200begins at step210by generating at the vehicle12a plurality of DTCs that are output from one or more diagnostic subtasks. Generally speaking, the vehicle12monitors a wide variety of vehicle functions using sensors that gather data relating to those functions. These sensors can monitor the temperature of vehicle components (e.g., the engine and the transmission via their respective fluids), the functionality of vehicle components (e.g., sensors in brake pads indicating significant wear) or of aspects of vehicle operation (e.g., odometer values or oxygen sensor data output). The vehicle telematics unit30can receive the data output by the sensors and use that data to generate one or more DTCs based on the data. In one example, data gathered by a sensor can be received at a vehicle system module42, which can then send the data to the vehicle telematics unit30via the communications bus44. Or in another example, the data can be received by the vehicle telematics unit30directly from a sensor.

Regardless of how the vehicle telematics unit30receives the data, the unit30can include one or more subtasks that analyzes the data and outputs DTCs or some other diagnostic output based on the data. Subtasks can be modular computer programs that are stored in memory54and executed by processor52. The subtasks are modular in the sense that two or more subtasks can work together (or be linked together) such that they collectively analyze the received data. In one example of how this can be accomplished, the data received from a sensor can include an identifier for each subtask that is linked by the Boolean operator AND. When the subtask (or subtasks) receives data, the subtask(s) can implement one or more diagnostic techniques to determine whether the data indicates that a vehicle function is outside of accepted or normal parameters. The subtask can make such a determination by comparing known ranges of acceptable data values with the received data values. When the received data is determined by the subtask to fall outside of the known range of acceptable data, the subtask (or linked subtasks) can generate a DTC.

The DTC that is generated can be followed by other DTCs, resulting in a plurality of DTCs. That is, the problem in vehicle function that is reflected by a first DTC may also be represented by one or more other, subsequent DTCs. Or one or more other, subsequent DTCs may reflect a different problem than the first DTC. But over a period of time, the vehicle telematics unit30or vehicle system module42can output more than one DTC or diagnostic output that reflects vehicle operation or some abnormal condition of vehicle operation/function. The method200proceeds to step220.

At step220, each DTC of the plurality of DTCs is stored at the vehicle12along with the condition or data that caused each DTC. In one implementation, the DTC can be stored along with a segment of data that caused it. The segment of data can be interpreted to determine the condition that caused each DTC. However, it should be appreciated that in some implementations the DTCs can be stored without the segment of data. For instance, the method200can use a sensor buffer for the data that is output from the sensor. The sensor buffer can be included with the processor52used by the vehicle telematics unit30, included with the memory54, or implemented in another location at the vehicle12. In that way the data received by the subtask is maintained in the sensor buffer for a period of time, which can be set to an amount that is greater than the time used by a subtask to identify an abnormal condition using that data. When the subtask identifies an abnormal condition of vehicle operation or function, the vehicle telematics unit30or the vehicle system module42can capture the data used to identify that condition stored in the sensor buffer. The captured data can be associated with the DTC by the vehicle telematics unit30using its processing capability (processor52) and stored at the vehicle12(memory54). This association can be carried out with DTCs that occur or are generated subsequent to earlier ones. And each DTC along with the data captured from the sensor buffer can be stored at the vehicle12until the vehicle12determines when to wirelessly transmit the plurality of DTCs and buffer data to a central facility, such as a back office facility represented by the computer18or the call center20. The method200proceeds to step230.

At step230, an ordinal number that is independent of time is assigned to each DTC and condition or sensor data. When the DTC is output or generated, it can be associated with or assigned an ordinal number. And these ordinal numbers can be assigned without reference to the time at which the DTC is output. That is, the DTC may be issued without accessing clock data. For instance, the method200can begin assigning ordinal numbers to DTCs after a period of normal vehicle operation has been interrupted by a DTC. At that point, an ordinal buffer can be accessed by the vehicle telematics unit30to obtain an ordinal number that is assigned to the first DTC. Both the DTC and the assigned ordinal number (and optionally data from the sensor buffer if it is used) can be stored at the vehicle12in memory54until it is accompanied by other DTCs/ordinal numbers and sent to the central facility.

In one example, the vehicle12may be operating normally until data received by a sensor is sent to a subtask that determines the data falls outside of acceptable ranges. The subtask can then generate a first DTC, which can cause the vehicle telematics unit30to access the ordinal buffer and obtain a first ordinal number to assign to the first DTC. The first ordinal number and the first DTC can then be temporarily stored in memory54. Thereafter, a second DTC may be generated due to a related or unrelated vehicle condition. The vehicle telematics unit30can access the ordinal buffer to obtain another (second) ordinal number to assign to the second DTC. Like the first DTC and first ordinal number, the second DTC and second ordinal number can be temporarily stored in memory54until it is sent to the central facility. In this example, the first ordinal number can be “01” while the second ordinal number can be “02.” However, it should be appreciated that the value of the ordinal numbers is arbitrary as is the numbering system (i.e., binary, hexidecimal, etc.) and other values/numbering systems can be used so long as they assign values to the DTCs in an ordinal manner. It will be appreciated that steps210-230may occur iteratively for each DTC generated such that after step230is carried out for a particular DTC, the process of steps210-230repeats for the next DTC that occurs. The method200proceeds to step240.

At step240, the plurality of DTCs and their corresponding conditions are wirelessly transmitted to a central facility along with the assigned ordinal numbers. After assigning the first ordinal number to the first DTC, the method200can continue monitoring for additional DTCs (and assigning additional ordinal numbers) for a defined amount of time. This amount of time can be determined in a variety of different ways. For example, the determination of when to stop monitoring for additional DTCs and when to send the plurality of DTCs and ordinal numbers can be based on a predetermined number of ignition cycles (e.g., how many times a driver starts/stops the vehicle12). It is possible to send with the DTCs and ordinal numbers the data that caused the DTCs but as noted above in some implementations this data is omitted. After the vehicle telematics unit30has detected the first DTC, the unit30can continue monitoring for additional DTCs until a predetermined number of ignition cycles occur (e.g., five). Once that number of ignition cycles has been detected, the vehicle telematics unit30can access the plurality of DTCs and the ordinal numbers assigned to those DTCs and wirelessly transmit them to a central facility. In another example, the vehicle telematics unit30can be programmed to monitor for additional DTCs after the first DTC is generated/detected for a fixed amount of time (e.g., 24 hours) that has been established by a vehicle manufacturer and stored at the vehicle12. When this amount of time has passed, the vehicle telematics unit30can access the plurality of DTCs and the ordinal numbers assigned to those DTCs and wirelessly transmit them to a central facility. These are only two of many possible ways that a determination regarding when to send the plurality of DTCs and ordinal numbers can be carried out. Once received by the central facility, the plurality of DTCs can be analyzed according to the order in which they occurred, which is known as a result of their ordinal numbers. The method200then ends.