OBD2 Standards documents

SAE standards documents on OBD-II

J1962 - Defines the connector used for the OBD-II interface.

J1850 - Defines a serial data protocol. There are 2 kinds - 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 DTCs 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

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 14320 no data

ISO 15031: Communication between vehicle and external equipment for emissions-related diagnostics, International Organization for Standardization, 2010.

Part 1: General information and use case definition

Part 2: Guidance on terms, definitions, abbreviations and acronyms

Part 3: Diagnostic connector and related electrical circuits, specification and use

Part 4: External test equipment

Part 5: Emissions-related diagnostic services

Part 6: Diagnostic trouble code definitions

Part 7: Data link security

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