ISO 13400-3:2016

Overview

ISO 13400-3:2016 - Road vehicles - Diagnostic communication over Internet Protocol (DoIP) - Part 3: Wired vehicle interface based on IEEE 802.3 - defines the physical (layer 1) and data link (layer 2) requirements for IP-based vehicle diagnostics using Ethernet. Focused on 100BASE-TX (and fallback 10BASE-T), the standard specifies how a vehicle’s Ethernet interface (DoIP Edge Node) and external test equipment must be wired, signalled and behaved to ensure reliable DoIP communication.

Key topics and technical requirements

• Physical and data-link baseline: Mandates support for IEEE 802.3 100BASE-TX and backward support for 10BASE-T as a fallback.
• Signal and wiring schematics: Requirements for twisted‑pair link segments, stub lengths and maximum cable lengths to ensure robust operation in automotive environments.
• PHY/MAC and Auto‑Negotiation: Support for Auto‑Negotiation and Auto‑MDI(X) to handle patch vs. cross‑over cable types and link speed negotiation.
• Activation/deactivation lines: Defines activation line behaviour so the DoIP Edge Node Ethernet controller can be enabled/disabled when test equipment is connected or removed; includes two activation-line circuit options and Spice simulation guidance.
• Discovery/identification: Mechanisms for discovery and identification of the in‑vehicle diagnostic Ethernet interface.
• Connector requirements: Mechanical and electrical diagnostic connector specifications, including isolation (1 500 V for 1 min between transformer coils per IEC 60950-1/IEEE 802.3) and identification of two Ethernet pin assignments.
• Compatibility and test equipment: Test equipment interface requirements and recommendations for ensuring interoperability with vehicle implementations.

Practical applications

• Vehicle diagnostics and repair tools (UDS/DoIP) for garages and service centers
• OEM/ECU manufacturers implementing DoIP-capable in‑vehicle gateways and Edge Nodes
• Diagnostic test equipment and interface hardware vendors (cable, connector, PHY design)
• Vehicle software update, calibration and flashing campaigns that require a stable IP-based link
• Conformance labs validating physical/data-link behaviour and activation-line operation

Who should use this standard

• Automotive OEMs and tier‑1 suppliers designing DoIP interfaces
• Diagnostic tool manufacturers and service tool integrators
• Test and validation engineers responsible for vehicle Ethernet interfaces
• Regulatory and homologation teams using standardised diagnostic channels

Related standards

• ISO 13400-1 / ISO 13400-2 (DoIP architecture, transport/network layers)
• ISO 14229 (UDS - unified diagnostic services)
• IEEE 802.3 (Ethernet physical/data‑link specifications)
• IEC 60950-1 (safety / isolation referenced)

Keywords: ISO 13400-3, DoIP, 100BASE-TX, IEEE 802.3, vehicle Ethernet, diagnostic interface, activation line, DoIP Edge Node, Auto-MDI(X), diagnostic connector.