ISO 22901-3-2018 PDF

Full title and description

Road vehicles — Open diagnostic data exchange (ODX) — Part 3: Fault symptom exchange description (FXD). This International Standard defines a machine-readable model and exchange format for representing fault‑symptom algorithms implemented as diagnostic software in electronic control units (ECUs), enabling standardized data exchange between software/function suppliers and vehicle manufacturers.

Abstract

ISO 22901-3:2018 specifies the FXD (Fault symptom eXchange Description) portion of the ODX family: an XML‑based, machine‑readable representation of diagnostic fault‑detection algorithms, associated calibration values and metadata so that tools can automatically generate documentation (summary sheets, repair & maintenance information), perform tool‑based validation and support lifecycle processes for ECU diagnostic functions.

General information

• Status: Published (International Standard; reviewed and confirmed in 2025).
• Publication date: February 2018 (Edition 1, 2018‑02).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 43.180 (Diagnostic, maintenance and test equipment for road vehicles).
• Edition / version: Edition 1 (2018).
• Number of pages: 198 pages.

Scope

ISO 22901-3:2018 defines a structured, machine‑readable description (FXD) of fault symptom algorithms used for on‑board diagnostics. The scope covers the information model, required elements and data structures necessary to describe how a detected condition (symptom) is derived from ECU data, including inputs, thresholds, timing, calibration parameters and metadata needed by downstream tools (documentation generators, diagnostic testers, validation suites). The intention is to standardize exchange between function/software suppliers and vehicle manufacturers and to enable automated processing of diagnostic logic.

Key topics and requirements

• Definition of the FXD information model for describing fault symptom algorithms and associated calibration values.
• XML representation and schema rules enabling tool‑readable exchange.
• Elements to express symptom inputs (signals/PIDs/parameters), logical conditions, thresholds, timing and hysteresis behavior.
• Metadata to link FXD content to ECU, software versions, variant coding and toolchain identifiers.
• Requirements to support generation of summary sheets and repair & maintenance information from FXD content.
• Guidance for interoperability with other ODX parts and with MVCI tool interfaces (alignment with related diagnostics standards).
• Examples and normative structures to support consistent authoring and tool implementation.

Typical use and users

Primary users are vehicle manufacturers (OEMs), ECU and diagnostic‑function suppliers, diagnostic tool vendors, test and validation teams, and aftermarket tool developers. Typical uses include: exchanging diagnostic detection logic between suppliers and OEMs; feeding automated documentation and type‑approval summary sheets; configuring diagnostic tools and test rigs; and supporting verification and validation of ECU diagnostic functions during development and production.

Related standards

ISO 22901-3 is part of the ODX family. Closely related documents include ISO 22901-1:2008 (ODX — Data model specification) and ISO 22901-2:2011 (ODX — Emissions‑related diagnostic data). The ODX model is intended to work with the Modular Vehicle Communication Interface (ISO 22900 series) and with diagnostic communication protocols such as those described in ISO 14229 (UDS) and ISO 15765 (DoCAN) in practical toolchains.

Keywords

ODX, FXD, fault symptom, diagnostic algorithm, ECU, vehicle diagnostics, XML, machine‑readable diagnostic data, diagnostic data exchange, ODX Part 3.

FAQ

Q: What is this standard?

A: ISO 22901-3:2018 is the part of the Open Diagnostic Data Exchange (ODX) suite that specifies the Fault symptom eXchange Description (FXD): a machine‑readable format to describe diagnostic fault‑detection algorithms for ECUs.

Q: What does it cover?

A: It covers the information model, required data elements and XML representation needed to express how symptoms are detected from ECU data (inputs, thresholds, timing, calibration values, metadata) so tools can consume, validate and generate documentation and test artefacts.

Q: Who typically uses it?

A: OEMs, ECU/function suppliers, diagnostic tool vendors, test & validation engineers and aftermarket diagnostic tool developers use it to exchange diagnostic logic and to automate documentation and tool configuration.

Q: Is it current or superseded?

A: This edition was published in February 2018. According to ISO's review record the publication was reviewed and confirmed in 2025 and therefore remained current following that review; it is still the standing edition as of February 28, 2026.

Q: Is it part of a series?

A: Yes — ISO 22901-3 is Part 3 of the ODX series. Other parts include ISO 22901-1 (data model specification) and ISO 22901-2 (emissions‑related diagnostic data). The ODX family is intended to interoperate with ISO 22900 MVCI and vehicle diagnostic communication protocols.

Q: What are the key keywords?

A: FXD, ODX, fault symptom, diagnostic algorithm, ECU, XML, diagnostic data exchange, vehicle diagnostics.