ISO 17978-1:2026

• Abstract:

  This document: gives an overview of the ISO 17978 series; specifies rules and basic principles for the service-oriented vehicle diagnostics (SOVD), conforming to the extended vehicle (ExVe) methodology, as specified in the ISO 20077 series; defines general terms.

• Status: Published
• Publication Date: 21-May-2026
• ICS: 01.040.43 - Road vehicle engineering (Vocabularies)
• ICS: 43.040.15 - Car informatics. On board computer systems
• Technical Committee: ISO/TC 22 - Road vehicles
• Drafting Committee: ISO/TC 22 - Road vehicles
• Current Stage: 6060 - International Standard published
• Start Date: 22-May-2026
• Due Date: 17-Apr-2026
• Completion Date: 22-May-2026

ISO 17978-1:2026 is an International Standard from ISO for road vehicles. It gives general information, definitions, rules and basic principles for service-oriented vehicle diagnostics (SOVD) in the extended vehicle (ExVe) context. It is the opening part of the ISO 17978 series, so it sets the common framework used by the later parts.

What does ISO 17978-1:2026 specify?

ISO 17978-1:2026 defines the shared frame for the ISO 17978 series: the scope of SOVD, the main rules and basic principles, and the general terms used across the series. It is written for the ExVe methodology in the ISO 20077 series and gives the terminology and conventions needed to read the rest of the SOVD documents.

Part	What it covers
ISO 17978-1	General information, definitions, rules and basic principles
ISO 17978-2	Use cases definition
ISO 17978-3	Application programming interface (API)

The document is organized into clauses on scope, normative references, terms and definitions, abbreviated terms, the series overview, conventions for rule and basic-principle identifiers, and the rules and basic principles themselves.

What are the key requirements of ISO 17978-1:2026?

ISO 17978-1:2026 does not define the full API behavior. Instead, it sets the design framework that SOVD solutions have to follow, especially when they interact with ExVe architecture, other diagnostic protocols, and multiple service users.

• Clause 5 places Part 1 as the overview of the series. It also points readers to Part 2 for use cases and Part 3 for the API, which matters because Part 1 is the entry point, not the implementation manual.
• Clause 6 defines the identifier format for rules and basic principles, using an element for the type, a number and a version. In practice, this lets teams cite a specific rule or principle unambiguously when writing requirements or test cases.
• Rule R_001 brings in the rules from ISO 20077-2:2018 and ties them to vehicle safety and security across the life cycle. That means SOVD design has to be aligned with vehicle protection, not only diagnostic convenience.
• BP_001 carries over the basic principles of ISO 20077-2:2018 and reflects the vehicle manufacturer’s two roles: vehicle designer/developer and service provider. This separation matters when post-sale diagnostics and repair are organized.
• BP_002 says SOVD must coexist with other diagnostic protocols. In practice, a task may use SOVD, another protocol, or a mix, depending on what is most efficient for the ECU, HPC and network path.
• BP_003 leaves the ExVe manufacturer to choose SOVD, another protocol, or both according to system needs and constraints. This is important when performance, hardware limits or software simplicity affect the diagnostic path.
• BP_004 allows a classic diagnostic adapter (CDA) to be placed inside or outside the physical vehicle. That gives flexibility in how legacy or protocol-translating functions are deployed.
• BP_005 says the ExVe manufacturer manages CDA updating according to vehicle configuration and evolution. In practice, CDA compatibility has to be maintained as ECUs and software change over the vehicle life cycle.
• BP_006 requires the SOVD implementation to manage concurrent access, using priorities, locking, or both. This matters when several diagnostics operators request operations at the same time through one or more ExVe interfaces.

What terms does ISO 17978-1:2026 define?

• service-oriented vehicle diagnostics (SOVD) - the diagnostic approach addressed by the ISO 17978 series.
• extended vehicle (ExVe) - an entity that extends beyond the physical vehicle and includes the road vehicle, off-board systems, external interfaces and their data communication.
• classic diagnostic adapter (CDA) - software that translates between SOVD and another diagnostic protocol.
• diagnostics operator - a natural person who performs a diagnostic procedure.
• high performance computer (HPC) - an in-vehicle device with high computing capacity, typically hosting multiple virtualized guest systems.
• rule - a fundamental design requirement to be complied with when designing an ExVe.
• use case - a sequence of interactions with a defined goal and measurable result.
• remote - an operation performed from a distance, where the operator is not co-located with the vehicle and the vehicle is connected through an external network.

Who uses ISO 17978-1:2026?

ISO 17978-1:2026 is used by vehicle manufacturers acting as ExVe manufacturers, diagnostic and service providers, and teams designing connected vehicle architectures. It is relevant for repair and maintenance, software update, configuration, access to fault information and data records, quality improvement, component development, system integration, fleet management, vehicle inspection, roadside assistance, insurance, and regulatory or type-approval activities.

Which standards are used with ISO 17978-1:2026?

ISO 20077-2:2018 is the normative reference. It provides the ExVe design methodology and the rules and basic principles that ISO 17978-1 applies to SOVD.

ISO 20077-1:2017 is used for shared terms such as ExVe, remote, diagnostics and use case. ISO 17978-2 defines SOVD use cases, and ISO 17978-3 defines the self-describing REST API based on HTTP, including the capability description and the mapping to UDS-based entities. ISO 14229-1 is cited in the bibliography as the UDS application-layer reference.

What does the ISO 17978-1:2026 document contain?

ISO 17978-1:2026 contains the series overview, abbreviated terms, the convention for identifying rules and basic principles, and six basic principles plus one rule. It also includes figures that show the OSI layers used in SOVD, the structure of the ISO 17978 series, and examples of co-located and remote diagnostic operation.

The examples show how SOVD compares with other diagnostic protocols, how a CDA can be placed and updated, and how multiple diagnostics operators can access the ExVe at the same time. In practice, the document is used to support system design, interface planning and diagnostic operation across the vehicle life cycle.

International
Standard
ISO 17978-1
First edition
Road vehicles — Service-oriented
2026-05
vehicle diagnostics (SOVD) —
Part 1:
General information, definitions,
rules and basic principles
Véhicules routiers — Diagnostic Véhicule Orienté Services
(SOVD) —
Partie 1: Informations générales, définitions, règles et principes
de base
Reference number
© ISO 2026
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 . 4
5 Overview of the ISO 17978 series . . 5
6 Conventions for identifying rules and basic principles and for specifying their content . 6
7 Rules and basic principles . 6
7.1 General .6
7.2 Rules .7
7.3 Basic principles .7
7.3.1 Basic principle 001 (BP_001) .7
7.3.2 Basic principle 002 (BP_002) .8
7.3.3 Basic principle 003 (BP_003) .8
7.3.4 Basic principle 004 (BP_004) .9
7.3.5 Basic principle 005 (BP_005) .10
7.3.6 Basic principle 006 (BP_006) .10
Bibliography .13

iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
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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
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This document was prepared by ISO/TC 22, Road vehicles, Subcommittee SC 31, Data communication.
A list of all parts in the ISO 17978 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 introduction of high performance computers (HPCs) in vehicles is associated with changes in the classical
electronic and electrical vehicle architectures. Besides classical distributed embedded electronic control
unit (ECU) architectures, domain- or zone-based architectures are also available. These architectures also
extend beyond the physical vehicle.
This extends the focus from checking hardware to also checking the functionality of applications. It requires
the recording of data such as memory usage, processor load, and the number of active services, as well as the
collection of log and trace files.
These topics result in challenges regarding the management of the vehicle life cycle. Some aspects to be
considered are:
— faster release and update cycles;
— increased requirements such as data protection and cybersecurity;
— state-of-the-art diagnostic API using current information technologies.
The ISO 17978 series define an API which standardizes the methods for:
— discovering the SOVD capabilities;
— performing diagnostics;
— (re-)configuring and re-programming;
— allowing the introduction of new functionalities.
Figure 1 shows the OSI layers of the ISO 17978 series.

v
a
Communication protocol.
b
Network technology depending on E/E vehicle network architecture.
Figure 1 — OSI layers of SOVD
vi
International Standard ISO 17978-1:2026(en)
Road vehicles — Service-oriented vehicle diagnostics
(SOVD) —
Part 1:
General information, definitions, rules and basic principles
1 Scope
This document:
— gives an overview of the ISO 17978 series;
— specifies rules and basic principles for the service-oriented vehicle diagnostics (SOVD), conforming to
the extended vehicle (ExVe) methodology, as specified in the ISO 20077 series;
— defines general terms.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 20077-2:2018, Road Vehicles — Extended vehicle (ExVe) methodology — Part 2: Methodology for designing
the extended vehicle
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
basic principle
design principle that is considered when designing an extended vehicle (3.8)
[SOURCE: ISO 20077-2:2018, 3.1]
3.2
capability
ability of a system, component or function to execute a defined task or provide a specific service
Note 1 to entry: Capabilities refer to concrete actions or functions that can be performed, such as executing a diagnostic
routine, retrieving sensor data, modifying configuration parameters or accessing logs.

3.3
classic diagnostic adapter
software that translates between the service-oriented vehicle diagnostics (SOVD) and another diagnostic
protocol
Note 1 to entry: The other diagnostic protocol may be a protocol that is not intended for diagnostic. Figure 2 shows
classic diagnostic adapter-enabling communication between SOVD and two other diagnostic protocols.
Figure 2 — Example of a classic diagnostic adapter that transcodes a SOVD API into different
diagnostic protocols
3.4
co-located
located in the same place as the vehicle
EXAMPLE Co-located diagnostics (3.6), co-located access.
Note 1 to entry: Figure 3 illustrates a co-located diagnostics operator (3.5) in relation to an extended vehicle (3.8).
Key
responsible operator
NOTE The colours used in this figure refer to the ones in ISO 20077-1.
Figure 3 — Co-located diagnostics operator using different network technologies and ExVe
interfaces
3.5
diagnostics operator
natural person that performs a diagnostic procedure
Note 1 to entry: A diagnostics operator can work at any service provider.

Note 2 to entry: In the ISO 17978 series, a co-located (3.4) diagnostics operator is responsible for the diagnostic
process.
3.6
diagnostics
diagnostic process
process including the detection process of possible vehicle malfunctions, the identification of the likely root
cause of these malfunctions and the appraisal of its relevance for the operation of the vehicle
[SOURCE: ISO 20077-1:2017, 3.2]
3.7
electronic control unit
embedded computing device used for vehicle control functions
3.8
extended vehicle
entity, still in accordance with the specifications of the vehicle manufacturer, that extends beyond the
physical boundaries of the road vehicle and consists of the road vehicle, off-board systems, external
interfaces and the data communication between the road-vehicle and the off-board systems
Note 1 to entry: Road vehicles without off-board systems and road vehicles equipped with telematics units are
extended vehicles.
[SOURCE: ISO 20077-1:2017, 3.5]
3.9
ExVe manufacturer
vehicle manufacturer responsible for the extended vehicle (3.8)
3.10
High performance computer
device owning high capacity of computing within the vehicle
Note 1 to entry: A high performance computer used in the ISO 17978 series typically hosts multiple virtualized guest
systems.
3.11
remote
performed on a vehicle from a distance where the operator responsible for the concerned operation is not
co-located (3.4) to the vehicle and where the vehicle is connected via an
...