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Automotive Diagnostic Systems - From OBD to Open Diagnostics Exchange format
 

Automotive Diagnostic Systems - From OBD to Open Diagnostics Exchange format

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Like in other fields, in automotive fault diagnosis, humans were increasingly removed from the loop, and computers took over until we are now at the stage of on-board diagnosis (OBD). Sensors are ...

Like in other fields, in automotive fault diagnosis, humans were increasingly removed from the loop, and computers took over until we are now at the stage of on-board diagnosis (OBD). Sensors are attached to various components, such as a cooling system's thermostat, and a wire runs from that through a harness and to a terminal block, which, in turn, is plugged into a diagnostic machine outside the car.

Find out more about Automotive Diagnostic Systems here: http://bit.ly/automotive-diagnostics

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    Automotive Diagnostic Systems - From OBD to Open Diagnostics Exchange format Automotive Diagnostic Systems - From OBD to Open Diagnostics Exchange format Document Transcript

    • Advanced automotive diagnostic systems From OBD to Open Diagnostics Exchange format (ODX) and limits and potentials of standardization processes Before getting to ODX, itself, we need a quick review of OBD. Electronic ignitions and fuel injection systems were the first major steps in getting away from mechanical fuel delivery and ignition. Being able to control the volume of fuel and sparking it at the right time are critical in controlling emissions, as well as making the vehicle more fuel efficient. Miniaturization and developments in computer technology enabled a closer control over that efficiency, and, along with it, the monitoring of contaminants. All the while the technology was unfolding it was realized that not only that it was beneficial but that it needed standardization. The diagnostic codes needed to be read in a manner better than specialized machines. A brief word is needed about standardization processes. They do not often occur in a convivial environment, as there are many competing commercial interests. Many times, a corporation will invest millions of dollars in developing a product, hoping that others will follow suit. There is a catch, however, if people can become dependent upon the way that product acts, then, the developers stand potentially to gain enormously from patent rights. A classic case of dependency was with the fiber optic FC (“ferrule connector”). During the early 1990s, there were many fights in the Electronic Industries Association and Institute for Electrical and Electronics Engineers standards committees among fiber optic cable developers about which standard was to prevail. It would be more convenient for everyone to follow, but more important, if everyone had to use company Xs product because it was the standard, then that dependency would be established. The same is true for automotive diagnostic equipment being standardized. Major corporations will send representatives to these standardization committees to thrash out the issues and present their arguments. While not the usual decorum, physical fights have been known to break out at these standardization meetings. In 1988 the Society of Automotive Engineers argued for a uniform diagnostic connector and standardized test signals. After it became apparent that the original OBD was not going to be very useful for universal use or for governments to incorporate into air quality legislation----------------------------------------------------------------------------------------------------------------------------------- IQPC GmbH | Friedrichstr. 94 | D-10117 Berlin, Germany t: +49 (0) 30 2091 3330 | f: +49 (0) 30 2091 3263 | e: eq@iqpc.de | w: www.iqpc.de Visit IQPC for a portfolio of topic-related events, congresses, seminars and conferences: www.iqpc.de
    • pertaining to automobiles, it was realized that further work was needed. Hence, came the OBD-II development. Yet, there still exist many problems in standardization. For example, automobile manufacturers use five basic OBD-II protocols: • J1850 PWM • J1850 VPW • ISO9141 • ISO14230 (also known as Keyword Protocol 2000) • CAN (ISO15765/SAEJ2480) [9] Chrysler, as well as every European manufacturer and the majority of the Asian manufacturers use ISO 9141 circuitry. GM uses SAE variable pulse width modulation (VPM) patterns, while Ford uses SAE J1850 pulse width modulation (PWM) patterns. These three communicate with the standard 16-pin, J1962 connector, but there are different protocols. One can differentiate between the pin usage by inspection. Systems using the ISO 9141 protocol locate a pin in position number 7 and a pin in either position number 2 or 10 position. SAE protocol-based systems do not have pins with connections in position number 7. There are systems called OBD-II that are compliant with laws and goes by the name of “European OBD (EOBD). There also is the Japanese variety, called ‘JOBD’ [10]. Specifically standard to the OBD-II are: • Type of connectors and number of pins – 16 • Signaling protocols that can be used – limited to the five • Format of messages • A list of what is to be monitored • Methods for data coding • Power pin that can connect to the car battery • List of diagnostic trouble codes (DTC). [11]----------------------------------------------------------------------------------------------------------------------------------- IQPC GmbH | Friedrichstr. 94 | D-10117 Berlin, Germany t: +49 (0) 30 2091 3330 | f: +49 (0) 30 2091 3263 | e: eq@iqpc.de | w: www.iqpc.de Visit IQPC for a portfolio of topic-related events, congresses, seminars and conferences: www.iqpc.de
    • Based on all this ODX was able to be created. As indicated by its name, “Open Diagnostics Exchange format”, or ODX, the industry was moving towards a uniform way of OBD. The Association for Standardization of Automation and Measuring Systems [12] is responsible for the ODX. ASAM was initiated by German car manufacturers and, in its own words, “...provides standards for data models, interfaces and syntax specifications for a variety of applications, such as testing, evaluation and simulation.” Actually, ODX is a “market name”, the actual name being “Data Model for ECU [electronic control unit] Diagnostics (also: Open Diagnostic Data Exchange Format) V2.2.0 18 May 2008 [13].” Since 1998, numerous automobile manufacturers from all around the world have joined, and jointly, they create standards for International Organization for Standards (ISO) approval [14]. The ODX, created in 2002, went numerous revisions, and is stable enough for use. There were 25 core members, 19 companies, and three countries that formed the standard [A report by the ODX ISO project leader, A. Schleicher is available on-line [15]. As specified by the ISO website: The ODX specification contains the data model to describe all diagnostic data of a vehicle and physical ECU, e.g. diagnostic trouble codes, data parameters, identification data, input/output parameters, ECU configuration (variant coding) data and communication parameters. ODX is described in Unified Modelling Language (UML) diagrams and the data exchange format uses Extensible Mark-up Language (XML). The ODX modelled diagnostic data describe: • protocol specification for diagnostic communication of ECUs; • communication parameters for different protocols and data link layers and for ECU software; • ECU programming data (Flash); • related vehicle interface description (connectors and pinout); • functional description of diagnostic capabilities of a network of ECUs; • ECU configuration data (variant coding). The purpose of ISO 22901-1:2008 is to ensure that diagnostic data from any vehicle manufacturer is independent of the testing hardware and protocol software supplied by any test equipment manufacturer. [16]----------------------------------------------------------------------------------------------------------------------------------- IQPC GmbH | Friedrichstr. 94 | D-10117 Berlin, Germany t: +49 (0) 30 2091 3330 | f: +49 (0) 30 2091 3263 | e: eq@iqpc.de | w: www.iqpc.de Visit IQPC for a portfolio of topic-related events, congresses, seminars and conferences: www.iqpc.de
    • Diagnostic tools and equipment While computerized automotive diagnosis was reserved initially for dealerships, not much time had elapsed until after market devices started appearing in auto parts stores. One can buy hand held devices that plug into the wiring harness of a car and determine what is wrong by reading diagnostic codes. However, these are not as complete as those devices available to dealership service technicians. At the dealerships, however, the devices are more complicated and give readouts that correspond to specifications described in automotive service manuals. Components other than the power train are diagnosed, such as airbags and brakes. Cars can be diagnosed while running, and some of the equipment includes display screens that give graphical representations of what is happening. The OBD-II standard requires a 16 pin female connector in the car that has the following configuration: 1. Manufacturer discretion. GM: J2411 9. - GMLAN/SWC/Single-Wire CAN. 2. Bus positive Line of SAE-J1850 PWM 10. Bus negative Line of SAE-J1850 PWM and SAE-1850 VPW only (not SAE-1850 VPW) 3. Ford DCL(+) Argentina, Brazil (pre 11. Ford DCL(-) Argentina, Brazil (pre OBD-II) 1997-2000, USA, Europe, etc. OBD-II) 1997-2000, USA, Europe, etc. Chrysler CCD Bus(+) Chrysler CCD Bus(-) 4. Chassis ground 12. - 5. Signal ground 13. - 6. CAN high (ISO 15765-4 and SAE- 14. CAN low (ISO 15765-4 and SAE- J2284) J2284) 7. K line of ISO 9141-2 and ISO 14230- 15. L line of ISO 9141-2 and ISO 14230- 4 4 8. - 16. Battery voltage [17] The nonstandard part is the allowance of the manufacturer to assign unspecified pins. The next logical step in complexity is an actual computer – desktop or laptop. These computers can accommodate any diagnostic setup with any of the OBD-II protocols. As can----------------------------------------------------------------------------------------------------------------------------------- IQPC GmbH | Friedrichstr. 94 | D-10117 Berlin, Germany t: +49 (0) 30 2091 3330 | f: +49 (0) 30 2091 3263 | e: eq@iqpc.de | w: www.iqpc.de Visit IQPC for a portfolio of topic-related events, congresses, seminars and conferences: www.iqpc.de
    • be expected, there is a greater depth of computation and analysis, along with higher screen resolution, and storage capacity to contain data on individual vehicles either for future retrieval or cross-vehicle analysis. Software varies, of course, but if one can imagine that something should be done with respect to OBD, in all probability, the application exists. From this level of computerization of OBD there emerged the XML-based data description format, the extensible markup language format, based on the hypertext markup language (HTML code used for web page development. With this format anyone, especially vehicle manufactures and their suppliers, can store and keep current data of the vehicle life cycle, including design, manufacturer, and maintenance data, in a standardized way. Both with hand-held and computer-based automotive diagnosis, those responsible for monitoring and enforcing vehicle emissions and safety standards can keep better track of various systems. So often in the past, the old methods of visual inspection and subjectivity in reading gauges and meters cannot keep pace with a technology demanding precise tolerances in measurements. Just a two percent variance on a sensor can mean the difference between whether the car operates within an acceptable limit or not. Not only for the automotive diagnostician but for the motorist various OBD-type devices are installed to warn the car owner of impending difficulties, with the idea that prevention of a problem is much simpler than repair. Sensor warning lights that give notice about problems concerning air bags, brakes or engine (such as “Check Engine” on the Chevrolet Cavalier) are a part of the chain of technology enabling accurate automotive diagnosis. Over the years, the value of flight data recorders has been realized. Knowing what brought down an airliner proves valuable in designing safer planes and improving how they are flown. The same applies to automobiles, and some insurance companies are giving discounts for the installation of a data recorder in automobiles. By monitoring the drivers behavior, it is thought that the safer drivers would pay a lower premium. The same system is being instituted for fleet drivers, as well [18]. Want to learn more about current technologies and developments in advanced automotive diagnostic systems? Visit our Download Centre for more articles, whitepapers and interviews: http://bit.ly/automotive-diagnostics----------------------------------------------------------------------------------------------------------------------------------- IQPC GmbH | Friedrichstr. 94 | D-10117 Berlin, Germany t: +49 (0) 30 2091 3330 | f: +49 (0) 30 2091 3263 | e: eq@iqpc.de | w: www.iqpc.de Visit IQPC for a portfolio of topic-related events, congresses, seminars and conferences: www.iqpc.de
    • References [1] VAD - http://acronyms.thefreedictionary.com/Vehicle+Automated+Diagnostic+System [2] http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=930966 [3] http://en.wikipedia.org/wiki/On-board_diagnostics#cite_note-3 - 1994 Corvette Service Manual, Book 2. General Motors Corporation. December 1993. pp. 6E3–A-166: 6E3–A-223. [4] http://en.wikipedia.org/wiki/On-board_diagnostics#EOBD [5] CCR Title 13 Section 1968.1 and 40 CFR Part 86 Section 86.094 [6] European emission standards Directive 98/69/EC - http://eur- lex.europa.eu/LexUriServ/LexUriServ.do?uri=CONSLEG:1998L0069:19981228:EN:PDF [7] http://en.wikipedia.org/wiki/On-board_diagnostics#cite_note-2 [8] http://en.wikipedia.org/wiki/On-board_diagnostics [9] http://www.obd-codes.com/faq/obd-ii-protocols.php [10] http://www.cvel.clemson.edu/auto/systems/OBD.html [11] http://en.wikipedia.org/wiki/On-board_diagnostics#EOBD [12] ASAM - http://www.asam.net/home/ [13] http://www.asam.net/home/standards/?no_cache=1&pointer=3 [14] http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=41207 [15] https://docs.google.com/viewer?url=http://www.testing- expo.com/europe/07txeu_conf/pres/day_2/day_2_3.pdf&embedded=true&chrome=true. [16] http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=41207 [17] http://en.wikipedia.org/wiki/On-board_diagnostics#EOBD [18] http://en.wikipedia.org/wiki/On-board_diagnostics#cite_note-3 [19] http://en.wikipedia.org/wiki/IEEE_12207 [20] http://www.chinavasion.es/wifi-obdii-diagnostics-tool-apple-ipad-iphone-ipod-touc-p- 1757.html [21] https://docs.google.com/viewer?url=http://www.elmelectronics.com/DSheets/ELM322DS.pdf &embedded=true&chrome=true [22] http://www.kwp2000.info/supported_cars----------------------------------------------------------------------------------------------------------------------------------- IQPC GmbH | Friedrichstr. 94 | D-10117 Berlin, Germany t: +49 (0) 30 2091 3330 | f: +49 (0) 30 2091 3263 | e: eq@iqpc.de | w: www.iqpc.de Visit IQPC for a portfolio of topic-related events, congresses, seminars and conferences: www.iqpc.de
    • [23] http://en.wikipedia.org/wiki/Controller_area_network, https://docs.google.com/viewer?url=http://focus.ti.com/lit/an/sloa101a/sloa101a.pdf&embed ded=true&chrome=true, http://zone.ni.com/devzone/cda/tut/p/id/2732 Further Reading http://www.google.com.mx/search?q=OBD&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en- US:official&client=firefox-a http://de.wikipedia.org/wiki/ODX http://www.cvel.clemson.edu/auto/systems/OBD.html https://docs.google.com/viewer?url=http://www.vector.com/portal/medien/cmc/press/PDG/O DX_HanserAutomotive_200612_PressArticle_EN.pdf&embedded=true&chrome=true http://en.wikipedia.org/wiki/European_emission_standards http://www.testing-expo.com/europe/07txeu_conf/pres/day_2/day_2_3.pdf https://docs.google.com/viewer?url=http://www.vector.com/portal/medien/cmc/press/PDG/O DX_HanserAutomotive_200612_PressArticle_EN.pdf&embedded=true&chrome=true https://docs.google.com/viewer?url=http://www.autoshop101.com/forms/h46.pdf&embedded =true&chrome=true http://www.epa.gov/obd/questions.htm http://www.epa.gov/obd/regtech/heavy.htm – OBD not yet required for heavy duty vehicles. http://en.wikipedia.org/wiki/On-board_diagnostics http://www.iqpc.com/Event.aspx?id=475354----------------------------------------------------------------------------------------------------------------------------------- IQPC GmbH | Friedrichstr. 94 | D-10117 Berlin, Germany t: +49 (0) 30 2091 3330 | f: +49 (0) 30 2091 3263 | e: eq@iqpc.de | w: www.iqpc.de Visit IQPC for a portfolio of topic-related events, congresses, seminars and conferences: www.iqpc.de
    • http://en.wikipedia.org/wiki/On-board_diagnostics#EOBD http://www.epathchina.com/citroen-and-peugeot-on-board-diagnostic-system-p-51.html In the U.S. various states have requirements, California being the traditional leader, here. e.g.: http://www.arb.ca.gov/msprog/obdprog/obdprog.htm, http://www.deq.virginia.gov/mobile/mobobd.html, https://docs.google.com/viewer?url=http://www.anr.state.vt.us/air/airtoxics/docs/onboarddia gnosticspamphlet.pdf&embedded=true&chrome=true, http://www.tn.gov/environment/apc/vehicle/obd.shtml https://docs.google.com/viewer?url=http://www.elmelectronics.com/DSheets/ELM322DS.pdf &embedded=true&chrome=true http://www.obd-codes.com/faq/obd-ii-protocols.php http://www.permoveo.ltd.uk/TechnicalResources/EOBDOBD2Whatsthedifference.aspx----------------------------------------------------------------------------------------------------------------------------------- IQPC GmbH | Friedrichstr. 94 | D-10117 Berlin, Germany t: +49 (0) 30 2091 3330 | f: +49 (0) 30 2091 3263 | e: eq@iqpc.de | w: www.iqpc.de Visit IQPC for a portfolio of topic-related events, congresses, seminars and conferences: www.iqpc.de
    • Appendix – Automotive diagnostic standards documents SAE standards documents on OBD-II • J1962 - Defines the physical connector used for the OBD-II interface. • J1850 - Defines a serial data protocol. There are 2 variants- 10.4 kbit/s (single wire, VPW) and 41.6 kbit/s (2 wire, PWM). Mainly used by US manufacturers, also known as PCI (Chrysler, 10.4K), Class 2 (GM, 10.4K), and SCP (Ford, 41.6K) • J1978 - Defines minimal operating standards for OBD-II scan tools • J1979 - Defines standards for diagnostic test modes • J2012 - Defines standards trouble codes and definitions. • J2178-1 - Defines standards for network message header formats and physical address assignments • J2178-2 - Gives data parameter definitions • J2178-3 - Defines standards for network message frame IDs for single byte headers • J2178-4 - Defines standards for network messages with three byte headers* • J2284-3 - Defines 500K CAN Physical and Data Link Layer • J2411 - Describes the GMLAN (Single-Wire CAN) protocol, used in newer GM vehicles. Often accessible on the OBD connector as PIN 1 on newer GM vehicles. SAE standards documents on HD (Heavy Duty) OBD • J1939 - Defines a data protocol for heavy duty commercial vehicles ISO standards • ISO 9141: Road vehicles — Diagnostic systems. International Organization for Standardization, 1989. • Part 1: Requirements for interchange of digital information • Part 2: CARB requirements for interchange of digital information • Part 3: Verification of the communication between vehicle and OBD II scan tool • ISO 11898: Road vehicles — Controller area network (CAN). International Organization for Standardization, 2003. • Part 1: Data link layer and physical signalling • Part 2: High-speed medium access unit • Part 3: Low-speed, fault-tolerant, medium-dependent interface • Part 4: Time-triggered communication----------------------------------------------------------------------------------------------------------------------------------- IQPC GmbH | Friedrichstr. 94 | D-10117 Berlin, Germany t: +49 (0) 30 2091 3330 | f: +49 (0) 30 2091 3263 | e: eq@iqpc.de | w: www.iqpc.de Visit IQPC for a portfolio of topic-related events, congresses, seminars and conferences: www.iqpc.de
    • • ISO 14230: Road vehicles — Diagnostic systems — Keyword Protocol 2000, International Organization for Standardization, 1999. • Part 1: Physical layer • Part 2: Data link layer • Part 3: Application layer • Part 4: Requirements for emission-related systems • ISO 15765: Road vehicles — Diagnostics on Controller Area Networks (CAN). International Organization for Standardization, 2004. • Part 1: General information • Part 2: Network layer services ISO 15765-2 • Part 3: Implementation of unified diagnostic services (UDS on CAN) • Part 4: Requirements for emissions-related systems Taken directly from: http://en.wikipedia.org/wiki/On-board_diagnostics#cite_note-3 This does not include the current ODX standard ISO 22901-1:2008.About IQPC:IQPC provides tailored conferences, large events, seminars and internal training programmes formanagers around the world. Topics include current information on industry trends, technicaldevelopments and regulatory rules and guidelines. IQPCs conferences are market leading events, highlyregarded for their opportunity to exchange knowledge and ideas for professionals from various industries.IQPC has offices in major cities across six continents including: Berlin, Dubai, London, New York, SaoPaulo, Singapore, Johannesburg, Sydney and Toronto. IQPC leverages a global research base of bestpractices to produce an unrivaled portfolio of problem-solving conferences. Each year IQPC offersapproximately 2,000 worldwide conferences, seminars, and related learning programs.----------------------------------------------------------------------------------------------------------------------------------- IQPC GmbH | Friedrichstr. 94 | D-10117 Berlin, Germany t: +49 (0) 30 2091 3330 | f: +49 (0) 30 2091 3263 | e: eq@iqpc.de | w: www.iqpc.de Visit IQPC for a portfolio of topic-related events, congresses, seminars and conferences: www.iqpc.de