ISO 16750-4:2023

Overview

ISO 16750-4:2023 - "Road vehicles - Environmental conditions and testing for electrical and electronic equipment - Part 4: Climatic loads" - is the fourth edition standard that defines climatic environmental stresses and recommended test methods for automotive electrical and electronic systems and components (including electric propulsion components) up to voltage class B. It specifies which climatic tests and requirements are appropriate based on the mounting location in/on the vehicle. The standard excludes motorcycles and mopeds and permits limited grandfathering for items released or under development before publication.

Key topics and technical requirements

This part of ISO 16750 focuses on climatic loads and prescribes a comprehensive set of tests and requirements, including:

• Operating temperature ranges and tests at constant temperature (low/high)
• Temperature step tests, temperature cycling, and rapid temperature change procedures
• Cold water shock (splash and submersion) methods
• Salt spray and corrosion tests, including cyclic and active tests for rotating machines
• Humid heat (cyclic), damp heat (steady state) and condensation tests
• Corrosion with mixed-gas flow, solar radiation (UV/ageing) tests
• Dust ingress and atmospheric pressure (altitude) testing
• Guidance on a code for climatic loads, protection against water and foreign objects, and documentation requirements
• Annexes with typical test selections by mounting location, cycle rationale, and insulation/pressure testing background

The 2023 edition integrates material from ISO 19453-4, adds new test methods (e.g., solar radiation, additional salt spray cycles), and distinguishes procedures for small/light versus large/heavy devices.

Practical applications - who uses it

ISO 16750-4 is used by:

• Automotive OEMs and Tier suppliers for specifying environmental qualification criteria
• Design and reliability engineers to validate thermal, humidity, corrosion and ingress robustness
• Test laboratories to implement standardized climatic test programs
• Quality, procurement and compliance teams to define contractual test requirements and acceptance criteria
• R&D teams for product development and pre‑qualification of modules, EV components, and power electronics

Typical uses include product design validation, supplier qualification, failure analysis, and regulatory/commercial documentation.

Related standards

Commonly used alongside:

• ISO 16750-1 (General)
• ISO 16750-2 (Electrical loads)
• ISO 20653 (IP protection code)
• ISO 4892 series (artificial light / solar ageing)
• ISO 9227 and ISO 11997 (salt spray and cyclic corrosion testing)

Keywords: ISO 16750-4, climatic loads, automotive electronics testing, temperature cycling, humidity test, salt spray, condensation, solar radiation, dust ingress, electric propulsion, voltage class B.