ISO 15031-3:2023

Road vehicles - Communication between vehicle and external equipment for emissions-related diagnostics - Part 3: Diagnostic connector and related electrical circuits: Specification and use

This document references the latest publication of SAE J1962. On-board diagnostic (OBD) regulations require road vehicles to be equipped with a standardized connector for purposes of access to OBD information by external test equipment. This document describes the requirements for the physical connection and associated pin usage to allow for standard access to the OBD data. This document is technically equivalent to SAE J1962 with the exception of the specific requirements identified and the specification of additional requirements related to right hand driven (RHD) vehicles.

Véhicules routiers — Communications entre un véhicule et un équipement externe pour le diagnostic relatif aux émissions — Partie 3: Connecteur de diagnostic et circuits électriques associés: spécifications et utilisation

General Information

• Status: Published
• Publication Date: 05-Feb-2023
• ICS: 13.040.50 - Transport exhaust emissions
• ICS: 43.040.10 - Electrical and electronic equipment
• ICS: 43.180 - Diagnostic, maintenance and test equipment
• Technical Committee: ISO/TC 22/SC 31 - Data communication
• Drafting Committee: ISO/TC 22/SC 31 - Data communication
• Current Stage: 6060 - International Standard published
• Start Date: 06-Feb-2023
• Due Date: 19-May-2023
• Completion Date: 06-Feb-2023

Relations

• Revises: ISO 15031-3:2016 - Road vehicles - Communication between vehicle and external equipment for emissions-related diagnostics - Part 3: Diagnostic connector and related electrical circuits: Specification and use
• Effective Date: 06-Jun-2022

Overview

ISO 15031-3:2023 is an international standard that specifies the diagnostic connector and related electrical circuits for communication between road vehicles and external equipment focused on emissions-related diagnostics. This standard ensures standardized physical connection and pin usage in on-board diagnostics (OBD), enabling external test devices to access vehicle diagnostic data.

The document references and aligns with the latest SAE J1962 publication but introduces additional requirements to accommodate right-hand driven (RHD) vehicles. It forms part of the broader ISO 15031 series designed to facilitate consistent, reliable emissions diagnostics globally.

Key Topics

• Standardized Diagnostic Connector (DLC)
  The core of ISO 15031-3:2023 is the specification of the physical data link connector (DLC) ensuring consistent communication interfaces for OBD access across vehicle makes and models.

• RHD Vehicle Requirements
  ISO 15031-3 updates SAE J1962 requirements, specifically addressing system performance, location, mounting security, and orientation tolerances for OBD connectors on right-hand drive vehicles to ensure accessibility and robustness.

• Connector Location and Mounting
  For RHD vehicles, the DLC must be located in the first-row foot well region and securely mounted to enable stable connection and disconnection during diagnostics. Mounting direction is limited to downward or rearward facing with a ±5° tolerance.

• Ethernet Support for DLC
  The standard incorporates support for Ethernet-based diagnostic communication following ISO 13400-4, outlining pin layouts and options for high-speed data communication within the vehicle diagnostic system.

• Additional Communication Line (ACL) for Pyrotechnic Devices
  Specification includes details for integrating an additional communication line on pin 15 for on-board pyrotechnic device control, aligned with ISO 26021-1 requirements for vehicle safety systems.

Applications

ISO 15031-3:2023 is essential for:

• Automotive Manufacturers
  Ensuring new vehicles comply with global OBD regulations by providing the specified DLC physical interface and electrical circuit requirements, including designs adaptive for RHD models.

• Diagnostic Tool Developers
  Creating standard external test equipment capable of interfacing with OBD data through standardized connectors and interpreting emissions diagnostics efficiently.

• Regulatory Bodies and Testing Facilities
  Supporting enforcement of emissions standards via consistent vehicle diagnostic access points, simplifying inspection and compliance testing processes.

• Service and Repair Centers
  Facilitating vehicle diagnostics by guaranteeing standardized access to on-board emissions-related data, regardless of vehicle origin or drivetrain orientation.

Related Standards

ISO 15031-3 is part of a comprehensive suite of standards for vehicle diagnostics and includes critical references such as:

• ISO 15031-1: Overview and use cases for vehicle-external equipment communication regarding emissions diagnostics.
• ISO 15031-2: Terminology guidance including terms, definitions, and acronyms critical for clear, consistent communication.
• ISO 13400-4: Ethernet-based high-speed data link connector specifications applicable for DLC Ethernet support.
• ISO 26021-1: Communication interface and connector layout for end-of-life activation of in-vehicle pyrotechnic devices.
• SAE J1962: Diagnostic connector specification forming the technical baseline for ISO 15031-3.

Additional related protocols and standards harmonized within this framework include ISO 9141-2, ISO 14230-4, ISO 11898-1 (CAN), SAE J1850, and OSI model conventions as per ISO/IEC 7498-1 and 10731.

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By adhering to ISO 15031-3:2023, stakeholders ensure interoperability, safety, and regulatory compliance in emissions diagnostics through a unified, internationally recognized diagnostic connector and electrical circuit standard for both left-hand and right-hand drive vehicles.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 15031-3
Third edition
2023-02
Road vehicles — Communication
between vehicle and external
equipment for emissions-related
diagnostics —
Part 3:
Diagnostic connector and related
electrical circuits: Specification and
use
Véhicules routiers — Communications entre un véhicule et un
équipement externe pour le diagnostic relatif aux émissions —
Partie 3: Connecteur de diagnostic et circuits électriques associés:
spécifications et utilisation
Reference number
© ISO 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 1
5 Conventions . 2
6 Technical requirements overview . 2
7 Physical layer . 2
7.1 PM – Data link connector (DLC) requirements . 2
7.1.1 PM – RHD vehicle DLC system performance requirements . 2
7.1.2 PM – RHD vehicle DLC location and position . 2
7.1.3 PM – RHD vehicle DLC securely mounted . 2
7.1.4 PM – RHD vehicle DLC mounting direction and tolerance . 2
7.2 PM – DLC Ethernet support layout . 3
7.3 PM – ACL for on-board pyrotechnic devices . 3
Bibliography . 4
iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 31,
Data communication.
This third edition cancels and replaces the second edition (ISO 15031-3:2016), which has been
technically revised.
The main changes are as follows:
— restructuration of the document;
— introduction of requirement numbers, names and definitions;
— update of the dated references to SAE J1962:201607.
A list of all parts in the ISO 15031 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
Introduction
The ISO 15031 series consists of a number of parts which, taken together, provide a coherent self-
consistent set of specifications to facilitate emissions-related diagnostics. ISO 15031-1 provides
an overview about communication between vehicle and external equipment for emissions-related
diagnostics. ISO 15031-2 through ISO 15031-7 are based on SAE recommended practices. This document
is based on SAE J1962 (diagnostic connector).
The first edition of this document was based on SAE J1962 and was inte
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