Climatic Chamber Configurator
Discover the Climatic Chamber Configurator
Our guide to choosing the climate chamber best suited to your needs.
ISO 16750 defines the environmental conditions and test methods for electrical and electronic components intended for road vehicles. It is the reference standard for the automotive industry and covers all stresses to which a component may be subjected during its operating life on board a vehicle.
In this guide we analyze the structure of the standard, the tests required by Part 4 (climatic loads) and how to perform them in a climatic chamber.
What is ISO 16750 and why is it important?
ISO 16750, whose full title is “Road vehicles — Environmental conditions and testing for electrical and electronic equipment”, is published byISO (International Organization for Standardization) and was last updated in 2023.
Every electronic component mounted on a vehicle—from the engine control unit to ADAS sensors, from the infotainment system to battery management modules for electric vehicles—must be proven to withstand the environmental conditions it will encounter during its lifecycle.
These conditions include:
- Extreme temperatures in the engine compartment (up to +125°C)
- Rapid temperature cycles between day and night, summer and winter
- High humidity and condensation formation
- Vibrations and mechanical shocks while driving
- Exposure to chemical fluids (fuel, brake fluid, road salt)
Structure of ISO 16750: the 5 Parts
The standard is divided into five parts, each dedicated to a category of environmental stress:
ISO 16750-1: General
It defines the general principles, the classification of mounting positions on the vehicle, and the reference operating conditions. It introduces the concept of "position code," which determines which tests to apply based on where the component is installed (engine compartment, passenger compartment, exterior, etc.).
ISO 16750-2: Electrical Loads
Covers power supply related tests : overvoltages, undervoltages, transients, reverse polarity, electrostatic discharge and electromagnetic interference.
ISO 16750-3: Mechanical Loads
It defines tests for vibration, mechanical shock, and free fall. Vibration profiles depend on the mounting position: a component in the engine compartment experiences very different vibrations than one in the passenger compartment.
ISO 16750-4: Climatic Loads
The most relevant section for climatic chamber testing. It defines temperature, humidity, thermal shock, and fluid resistance tests. We will explore this section in more detail later.
ISO 16750-5: Chemical Loads
Covers resistance to fluids and chemicals: fuels, lubricants, coolant, windshield washer fluid, road salt and other agents present in the vehicular environment.
ISO 16750-4: Climatic Testing in Detail
Part 4 of ISO 16750 is the one that directly concerns those who use environmental chambers and climatic chambers for automotive testing. Here are the main tests.
Low Temperature Test
Check the component's operation at subzero temperatures. The values depend on the mounting position:
- Cockpit: -40°C
- Engine compartment: -40°C
- Outside (unprotected): -40°C
The sample is stabilized at the target temperature and maintained for at least 24 hours, during which it must function properly.
High Temperature Test
Maximum temperatures vary significantly depending on location:
- Cockpit: +85°C
- Engine compartment (away from engine): +105°C
- Engine compartment (near engine/exhaust): +125°C
- Directly on engine/transmission: up to +150°C
The component must operate without degradation for at least 96 hours at the maximum expected temperature.
Thermal Cycling Test
It simulates the daily and seasonal cycles a vehicle undergoes throughout its life. The test includes:
- Transition from -40°C to +85°C (or higher for engine compartment)
- Rate of change: typically 2°C/min
- Holding time: 30 minutes at each end
- Number of cycles: 100 to 1,000 cycles depending on severity level
This is one of the longest and most demanding tests: 1,000 cycles at 2°C/min can require weeks of continuous operation of the climatic chamber.
Thermal Shock Test
Simulates sudden temperature changes, such as starting the engine in winter or moving from a heated garage to the outside. Typical parameters are:
- From -40°C to +125°C
- Transition time: <30 seconds (liquid immersion thermal shock) or <3 minutes (dual-zone chamber)
- Number of cycles: 100 to 500
Humidity Test
Evaluate resistance to condensation and high relative humidity:
- Constant humid heat: +40°C at 93% RH for 240 hours (10 days)
- Cyclic humid heat: cycles between +25°C/95% RH and +65°C/93% RH for 10 cycles of 24 hours, with condensation forming in the cooling phase
Classification of Mounting Positions
One of the most characteristic aspects of ISO 16750 is the classification by mounting position, which determines the severity of the tests:
| Code | Position | Min Temp | Max Temp |
|---|---|---|---|
| P1 | Directly onto the engine/transmission | -40°C | +150°C |
| P2 | Engine compartment (near the engine) | -40°C | +125°C |
| P3 | Engine compartment (away from the engine) | -40°C | +105°C |
| P4 | Cockpit (not heated by the sun) | -40°C | +85°C |
| P5 | Cockpit (heated by the sun) | -40°C | +105°C |
| P6 | External | -40°C | +80°C |
ISO 16750 and Electric Vehicles
As the electric vehicle (EV) market grows , ISO 16750 takes on an even more critical role. EV-specific components— Battery Management System (BMS), inverters, on-board chargers, power modules —must all pass Part 4 climate tests.
In particular, the thermal management of batteries requires specific tests that combine ISO 16750-4 with dedicated standards such as IEC 62660 for lithium cells.
FDM manufactures battery test chambers designed to perform tests compliant with both standards.
Climatic Chamber Requirements for ISO 16750-4
To perform all Part 4 tests, the climatic chamber must ensure:
- Temperature range: -40°C to +150°C (to cover position P1)
- Humidity control: 10% to 95% RH, accurate to ±3% RH
- Thermal stability: ±1°C at test temperature
- Thermal ramps: at least 2°C/min for cycling, up to 15°C/min for thermal shock
- Programmability: Automatic execution of up to 1,000 cycles without operator intervention
- Usable volume: variable based on the size of the components (from control units to complete battery modules)
The FDM Solution for ISO 16750 Automotive Testing
For over 70 years, FDM Environment Makers has been the automotive for environmental simulation.
FDM environmental chambers cover a range from -70°C to +180°C with humidity control up to 98% RH, exceeding all ISO 16750-4 requirements for any mounting position.
For long-duration tests such as 1,000-cycle thermal cycling, FDM chambers offer full programmability and continuous 24/7 operation without operator intervention.
Norms and Standards Related to ISO 16750
ISO 16750 integrates with other international standards and industry regulations that automotive manufacturers must consider in the environmental qualification of components:
- SAE J1211 — Handbook for the Rugged Design of Automotive Electronic Components, an SAE guideline complementary to ISO 16750.
- UNECE WP.29 — International regulatory framework for vehicle type approval, which calls for equivalent environmental tests in different regulations (R10 EMC, R100 electric vehicles).
- LV 124 / LV 148 — Consortium specifications of German manufacturers (Volkswagen Group, Audi, Mercedes, BMW) for 12V and 48V electrical and electronic components, derived from ISO 16750 with more stringent requirements.
- JASO D 014 — Japanese Automotive Standards Organization standard for environmental testing of automotive electronic components, used by the Asian supply chain.
- ASTM D4329 — Complementary practice for UV exposure of automotive plastics, often referred to in conjunction with ISO 16750-4 for vehicle interiors.
Discover FDM Environmental Chambers or contact us for technical advice on ISO 16750 testing.
FAQ — Frequently Asked Questions about ISO 16750
Who does ISO 16750 apply to?
To all manufacturers of electrical and electronic components intended for road vehicles: control units, sensors, actuators, power modules, infotainment systems, LED lighting and any electronic device mounted on cars, trucks, buses and motorcycles.
What is the difference between ISO 16750 and IEC 60068?
IEC 60068 defines generic environmental tests for electronic components in any industry. ISO 16750 is specifically designed for the automotive industry and includes test conditions calibrated for vehicle mounting locations and the actual operating conditions of a road vehicle.
Is ISO 16750 mandatory?
It is not required by law, but it is required by all major automotive manufacturers (OEMs) as a contractual requirement for component approval. It is effectively a mandatory standard for entry into the automotive supply chain.
How long does a full ISO 16750-4 test cycle take?
It depends on the severity level. A full program with 1,000-cycle thermal cycling, humidity testing, and thermal shock can require 4 to 8 weeks of continuous testing in a climate chamber.
Authoritative Sources
- ISO 16750-1/2/3/4/5 — Road vehicles — Environmental conditions and testing for electrical and electronic equipment.
- SAE International — SAE J1211, SAE J1455 standards for automotive environmental qualification.
- AEC (Automotive Electronics Council) — AEC-Q100 — Stress Test Qualification for automotive Integrated Circuits.
- VDA — Verband der Automobilindustrie — Standard LV 124, LV 148 for German electronic components.
- UNECE — UN Vehicle Regulations — ECE R10 Electromagnetic Compatibility of Vehicles.
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Do you need to pass a regulatory test or are you looking for a chamber designed to your test protocol? Tell us your needs: the FDM technical team will respond to you, without intermediaries.
