ISO 11451-2:2025

Overview

ISO 11451-2:2025 - Road vehicles - Vehicle test methods for electrical disturbances from narrowband radiated electromagnetic energy - Part 2: Off-vehicle radiation sources - specifies a standardized method to test the immunity of passenger cars and commercial vehicles to continuous narrowband electromagnetic fields originating from sources external to the vehicle. Applicable regardless of propulsion type (ICE, diesel, electric motor) and adaptable to other vehicle types, this fifth edition updates charging-mode test setups and adds wireless power transfer (WPT) considerations. The standard works alongside ISO 11451-1, which defines general conditions, definitions and basic test principles.

Key topics and technical requirements

• Test conditions and location: Defined environmental and facility requirements for reproducible off-vehicle radiated immunity testing.
• Test instrumentation: Requirements for field-generating devices, antennas, transmission line systems (TLS), and field probes used for calibration and measurement.
• Field calibration and field uniformity: Calibration procedures (including updated 4-probe calibration applicable up to 6 GHz) and field uniformity criteria (modified up to 6 GHz with an added measurement position and averaging methods).
• Vehicle test set-up: Detailed vehicle placement, shielded-enclosure constraints, antenna/TLS placement and orientation rules, plus guidance for testing vehicles in different power/charging conditions.
• Charging-mode configurations: Specific procedures for vehicles:
  • Not connected to the grid
  • Charging mode 1/2 (AC powered without communication)
  • Charging mode 3/4 (AC or DC with communication)
  • Wireless charging (WPT) - newly included in this edition
• Test procedure and reporting: Test planning, stepwise calibration, the vehicle test process, monitoring/stimulation of the device under test (DUT), and required test report contents.
• Performance classification & uncertainty: Annex A defines Function Performance Status Classification (FPSC); Annex B addresses instrumentation uncertainty; Annexes C and D cover multi-signal testing and large-vehicle guidance.

Practical applications and who uses it

ISO 11451-2:2025 is used by:

• Automotive OEMs and tier suppliers for EMC/EMI design validation
• Accredited EMC test laboratories for standardized vehicle immunity testing
• Electric vehicle (EV) and charging-station developers evaluating charging-mode susceptibility and WPT interactions
• Regulatory, certification and conformity-assessment bodies requiring consistent test evidence
• R&D teams and systems engineers performing compatibility and robustness assessments of in-vehicle electronics

Practical outcomes include validated vehicle system reliability under real-world radiated interference, evidence for compliance and safer integration of EV charging systems.

Related standards

• ISO 11451-1 - general test conditions, definitions and test principles for narrowband radiated immunity.
• ISO/IEC directives referenced for standard development and technical alignment.