ISO 15765-4-2021 PDF

Full title and description

Road vehicles — Diagnostic communication over Controller Area Network (DoCAN) — Part 4: Requirements for emissions-related systems. This International Standard defines requirements for CAN‑based communication between a vehicle's in‑vehicle network and the diagnostic link connector to support emissions‑related diagnostics and external test equipment interoperability.

Abstract

Specifies requirements to enable CAN‑based diagnostic communication to establish, maintain and terminate communication with devices connected to the vehicle diagnostic link connector. It focuses on emissions‑related system requirements and the behaviours needed for plug‑and‑play operation with external test equipment; it does not mandate in‑vehicle CAN network architecture.

General information

• Status: Published
• Publication date: 30 July 2021 (Edition published July 2021)
• Publisher: International Organization for Standardization (ISO)
• ICS / categories: 43.180 (Diagnostic, maintenance and test equipment); 43.040.15 (Car informatics, on‑board computer systems)
• Edition / version: Edition 4 (2021)
• Number of pages: 25 (ISO edition page count)

Key bibliographic details from the ISO publication record and national standards bodies.

Scope

This part of ISO 15765 specifies the requirements for Controller Area Network (CAN) based diagnostic communication between the in‑vehicle network and the vehicle diagnostic link connector specifically for emissions‑related systems. It defines behaviors and timing needed for establishing, maintaining and terminating communication with external test equipment and connected devices; it deliberately does not prescribe vehicle internal CAN architecture.

Key topics and requirements

• Requirements for CAN‑based diagnostic communication paths between the vehicle network and the diagnostic link connector.
• Behavioral and timing requirements to support emissions‑related diagnostics and interoperability with external test equipment.
• OSI layer requirements (network/transport/service interfaces) necessary to support diagnostic services used for OBD/WWH‑OBD and other emissions diagnostics.
• Compatibility and interaction with transport protocols (DoCAN / ISO‑TP) and application layer services such as UDS (ISO 14229) and OBD service sets (ISO 15031 / SAE J1979).
• Notes on applicability to Classical CAN and CAN FD (standard does not mandate which CAN variant other referencing standards must require).
• Requirements to enable plug‑and‑play operation between vehicles and external test equipment for legislated emissions testing.

Summary synthesised from the standard and complementary normative documents.

Typical use and users

Used by vehicle OEM integration teams, ECU and module suppliers, diagnostic tool and scan‑tool manufacturers, regulatory bodies and test laboratories, and service/repair organizations that implement or verify emissions‑related diagnostic access and interoperability. The standard is used when designing vehicle diagnostic interfaces, developing external test equipment, and verifying compliance with emissions diagnostic regulations.

Related standards

Commonly referenced and related documents include other parts of the ISO 15765 series (Part 1 — general information and use cases; Part 2 — transport protocol / ISO‑TP), ISO 14229 (UDS session and service layers), ISO 15031 (OBD communications and service sets), ISO 27145 (WWH‑OBD), ISO 11898 (CAN physical/data link), ISO 26021 (end‑of‑life pyrotechnic activation) and applicable SAE diagnostics specifications (for example SAE J1979). Implementers should consult these documents together for complete diagnostic system design.

Keywords

DoCAN, ISO 15765‑4, emissions diagnostics, OBD, WWH‑OBD, UDS, ISO‑TP, CAN, CAN FD, diagnostic link connector, transport protocol, external test equipment, ECU, scan tool.

FAQ

Q: What is this standard?

A: ISO 15765‑4:2021 is Part 4 of the DoCAN family: an ISO standard that defines requirements for CAN‑based diagnostic communication between the vehicle network and the diagnostic link connector specifically for emissions‑related systems.

Q: What does it cover?

A: It covers behavioural, timing and interface requirements needed to establish, maintain and terminate CAN‑based diagnostic communication to support emissions testing and interoperability with external test equipment; it does not prescribe vehicle internal CAN network architecture.

Q: Who typically uses it?

A: Vehicle manufacturers, ECU suppliers, diagnostic tool makers, regulatory test labs and service/repair organisations that implement or verify emissions‑related diagnostics and diagnostic interfaces.

Q: Is it current or superseded?

A: ISO 15765‑4:2021 (Edition 4) was published in July 2021 and replaces the 2016 edition; it is the current ISO edition published in 2021 according to the ISO bibliographic record. Users should confirm national adoption/confirmation status in their country before compliance work.

Q: Is it part of a series?

A: Yes — it is one part of the ISO 15765 DoCAN series (Parts 1, 2, 3 historically, and Part 4). Implementations normally use ISO 15765‑2 (transport/ISO‑TP) together with session/application standards such as ISO 14229 (UDS) and emissions‑specific documents like ISO 15031 and ISO 27145.

Q: What are the key keywords?

A: DoCAN, CAN, CAN FD, ISO‑TP, UDS, OBD, WWH‑OBD, diagnostic link connector, emissions diagnostics, transport protocol, external test equipment.