On-Board Diagnostics

J1962 Diagnostic Connector Equivalent to ISO/DIS 15031-3: December 14, 2001
J2012 Diagnostic Trouble Code Definitions
J1939 Recommended Practice for a Serial Control and Communications Vehicle Network
J1979 E/E Diagnostic Test Modes
J1930 Electrical/Electronic Systems Diagnostic Terms, Definitions, Abbreviations, and Acronyms – Equivalent to ISO/TR 15031-2
J1978 OBD II Scan Tool – Equivalent to ISO/DIS 15031-4: December 14, 2001
J2819 TP2.0 Vehicle Diagnostic Protocol
J1699/2 OBD II Related SAE Specification Verification Test Procedures
J1699/3 OBD II Compliance Test Cases
J2012 Diagnostic Trouble Code Definitions Equivalent to ISO/DIS 15031-6
J2809 Honda Diagnostic Serial Data Link Protocol – ABS/VSA System
J2818 Keyword Protocol 1281
J2819 TT2.0
J1708 Serial Data Communications Between Microcomputer Systems in Heavy-Duty Vehicle Applications.

Programmable ECUs

J2534/1 Recommended Practice for Pass-Thru Vehicle Programming
J2534/2 Optional Pass-Thru Features
J2534/3 Conformance Test Cases

Vehicle Networks

J2740 General Motors UART Serial Data Communications
J1213 Glossary of Vehicle Networks for Multiplexing and Data Communications
J2610 Serial Data Communication Interface

CAN

J2284/1 High Speed CAN (HSC) for Vehicle Applications at 125 Kbps
J2284/2 High Speed CAN (HSC) for Vehicle Applications at 250 Kbps
J2284/3 High-Speed CAN (HSC) for Vehicle Applications at 500 Kbps
J2866 SafeCAN: Using CAN in Real-time Deterministic and Safety-Critical Applications
J2411 Single Wire CAN Network for Vehicle Applications

Class A Multiplexing

J2057/1 Class A Application/Definition
J2057/2 Class A Multiplexing Actuators
J2057/3 Class A Multiplexing Sensors
J2057/4 Class A Multiplexing Architecture Strategies

Class B Data Communication Network Messages

J1850 Class B Data Communications Network Interface
J2178/1 Class B Data Communication Network Messages – Detailed Header Formats and Physical Address Assignments
J2178/2 Class B Data Communication Network Messages – Part 2: Data Parameter Definitions
J2178/3 Class B Data Communication Network Messages – Part 3: Frame IDs for Single-Byte Forms of Headers
J2178/4 Class B Data Communication Network Messages–Message Definitions for Three Byte Headers

LIN

J2602/1 LIN Network for Vehicle Applications
J2602/2 LIN Network for Vehicle Applications Conformance Test

ISO

ISO (International Organization for Standardization) is the world's largest developer and publisher of International Standards.

ISO is a network of the national standards institutes  of 163 countries, one member per country,

with a Central Secretariat in Geneva, Switzerland, that coordinates the system (source www.iso.org)

Following standards (relevant for diagnostics) were published by ISO:

- ISO 9141 CARB requirements for intervhange of digital information
- ISO 14230-1/2/3/4 KeyWord Protocol 2000 (Physical Layer / K-Line, Data Link Layer / Transport Protocol, Application Layer / Services and OBD)
- ISO 15765-1/2/3/4 Diagnostics over CAN (Physical Layer / CAN, Transport Protocol, Implementation / Services, and OBD)
- ISO 22900-2 D-PDU API (Protocol data unit API)
- ISO 14229-1 Unified Diagnostic Services UDS (Diagnostic Services)
- ISO 13209-1 OTX (Open Test sequence eXchange format)
- ISO 15031-1/2/3/4/5/6 OBD (emission related communication, terms, connector, external equipment, services, DTCs) <SAE J1979>
- ISO 11898-1/2/3/5 CAN (Data Link Layer, high speed medium access, low speed and fault-tolerant interface and low power mode for high speed medium).
- ISO 13400-1/3 DoIP (Diagnostics over IP, wired vehicle interface)
- ISO 11519-4 <SAE J1850>
- ISO 27145 Road vehicles -- Implementation of World-Wide Harmonized On-Board Diagnostics (WWH-OBD) communication requirements <CAN or TCP/IP>
- ISO 13400 Diagnostic communication between test equipment and vehicle over Internet Protocol (DoIP)  
- ISO 16081 UDS o FlexRay

SAE

SAE International is a global association of more than 128,000 engineers and related technical experts in the aerospace, automotive and commercial-vehicle industries.

SAE International's core competencies are life-long learning and voluntary consensus standards development.

SAE International's charitable arm is the SAE Foundation, which supports many programs, including A World In Motion® and the Collegiate Design Series (source www.sae.org).

Following standards (relevant for diagnostics) were published by SAE:
- SAE J2434-1/2 Pass Thru (standard vehicle interface for reprogramming, optional feature)

SERIAL COMMUNICATION INTERFACES

Basically the diagnostic communication is an serial data exchange between the so called client (tester) and server (ECU – electronic control unit).

Currently standardized interfaces on the OBD connector are:

- K-Line (ISO 14230), up to 128 kBd (typical 9600 or 10400 Bd)
- CAN (ISO 11898), up to 1 MBd (typical 50/100 kBd for low speed and 500 kBd for high speed)
- Ethernet (ISO 14300, next generation of vehicle access, up to 1Gbit, typical 10 Mbit)

COMMUNICATION PROTOCOLS

Main objective of a protocol is the definition of timing parameters, requests and responses to read and write data (commands),

where the execution of commands is done in order to so called sessions and sessions were activated by security access level using seed&key mechanism.

Typical r/w commands are: session handling, identification data, variant coding, update programming, fault memory, sensor test etc.

Basically there are three types of standardized diagnostic communication protocols:

- OBD (ISO 15301-5 and ISO 14230-4), Modes used on K-Line and CAN 
- KWP2000 (ISO 14230-3), Services are used on K-Line and CAN 
- UDS (ISO 14229-1), Services are used on CAN and Ethernet

CAN physical layer standards

There are several CAN physical layer standards:

‡ ISO 11898-1: CAN Data Link Layer and Physical Signaling
‡ ISO 11898-2: CAN High-Speed Medium Access Unit
‡ ISO 11898-3: CAN Low-Speed, Fault-Tolerant, Medium-Dependent Interface
‡ ISO 11898-4: CAN Time-Triggered Communication 
‡ ISO 11898-5: CAN High-Speed Medium Access Unit with Low-Power Mode 
‡ ISO 11898-6: CAN High-speed medium access unit with selective wake-up functionality

‡ ISO 11992-1: CAN fault-tolerant for truck/trailer communication

‡ ISO 11783-2: 250 kbit/s, Agricultural Standard

‡ SAE J1939-11: 250 kbit/s, Shielded Twisted Pair (STP)
‡ SAE J1939-15: 250 kbit/s, Unshielded Twisted Pair (UTP) (reduced layer)

‡ SAE J2411: Single-wire CAN (SWC)

DIAGNOSTIC INTERFACES

The diagnostic interfaces provide a communication link between OBD system and external test equipment.

There are three physical diagnostic interfaces:

1) SAE J1850 (ISO 11519-4) – Class B data communication interface:

two alternative physical implementations:

single-wired 10.4 kbit/s VPW (Variable Pulse Width) and two-wired differential 41.6 kbit/s PWM (Pulse Width Modulation).

Application: mainly GM and Ford.

2) ISO 9141-2 / ISO 14230 – K-line interface:

10.4 kbit/s, single-wired interface, compatible with UART/SCI byte/word interface.

The optional L-line is used only during initialization.

Application: most European and Asian manufacturers, also Chrysler and GM.

3) ISO 15765-4 (ISO 11898) – CAN interface:

high speed two-wired differential interface, 500 kbit/s.

Application: will be mandatory after model year 2008.

UDS - 全球统一车载电脑(ECU) 自诊断服务 标准号 ISO-14229 : 2006 (ECU制造标准)

WWH-OBD 全球统一车载电脑(ECU) 自诊断终端 标准号 ISO-27145 : 2006 (解码器标准)

MCD - 全球统一 车辆 M_测量 C_标定 D_诊断 (网络服务 + 远程或本地)

ODX - 开放的汽车XML数据库标准 ASAM MCD3 核心就是使用ODX 标准数据库 标准号 ISO-22901

VCI - 汽车通讯接口

MVCI - 模块化汽车通讯接口 标准号 ISO-22900 (靠ODX数据库控制通讯)

VAS5054A - 符合 ISO-22900 标准的 VCI