Direct answer
Define the test items by mounting location, not by part name. Engine bay, body, chassis and passenger cabin see completely different temperature, vibration and ingress loads. Fix the mounting location first, look up the severity parameters in the corresponding part of ISO 16750 / GB/T 28046, then layer the OEM corporate standard on top — that makes an executable test list.
Why the mounting location comes first
The same ECU mounted in the engine bay and in the passenger cabin can see an upper temperature limit more than 40 ℃ apart, and an even larger difference in vibration level. Severity parameters in the standards are given as a matrix of mounting location plus vehicle type, not by part category. So the question "which tests does this part need" presupposes the question "where is it mounted".
Four typical mounting locations
| Mounting location | Temperature | Vibration | Additional considerations |
|---|---|---|---|
| Engine bay | Sustained high temperature with severe swings | Engine cyclic vibration superimposed on road excitation | Fluid and chemical load, thermal ageing, ingress protection |
| Passenger cabin / body | Moderate, though solar load can reach high temperatures | Predominantly road-induced random vibration | Solar radiation, VOC and odour, flame retardancy |
| Chassis / near the suspension | Temperature swings combined with mud and water spray | Shock and large-displacement vibration | Stone impact, salt mist, IP rating |
| Near the drivetrain / rotating parts | Moderate to high temperature | High-frequency vibration | Strength of rotating parts, dynamic balance |
The table is qualitative. For the actual temperature limits, vibration profile and duration, look up the corresponding part of ISO 16750 by mounting location, or follow the customer's corporate standard.
How to break down the test list
Climatic load (ISO 16750-4 / GB/T 28046.4)
- Low temperature storage and operation
- High temperature storage and operation
- Temperature cycling / thermal shock
- Damp heat (constant and cyclic)
- Solar radiation (exterior and interior parts)
- Salt mist / cyclic corrosion
- Ingress protection (IP)
Mechanical load (ISO 16750-3 / GB/T 28046.3)
- Random vibration (PSD profile selected by mounting location)
- Sine vibration
- Mechanical shock
- Free fall (small parts)
- Stone impact (chassis parts)
Electrical load (ISO 16750-2 / GB/T 28046.2)
- DC supply voltage range
- Overvoltage and superimposed alternating voltage
- Voltage dip and recovery (cranking conditions)
- Reverse voltage, ground offset, open circuit, short circuit
Material and chemical load
- Flame retardancy
- VOC, odour and fogging (interior parts)
- RoHS / REACH compliance (parts for export)
How to set severity — do not guess
Severity is decided by three factors together: mounting location, vehicle type (passenger car / commercial vehicle / off-highway) and the customer standard. Miss one and the plan is incomplete.
Without a customer standard you can issue a list at the default level of the national or international standard, but label it clearly as the default level and have the customer confirm. The default is generally not the most severe level, and taking it straight to acceptance testing often falls short.
Four things to confirm before submitting samples
- Mounting location and vehicle type
- The reference standard and revision specified by the customer
- Whether powered monitoring is required (essential wherever functional failure is judged)
- The appearance acceptance criteria (many items judge function and appearance together)
Where we stand
TMC LAB holds both CMA and CNAS accreditation and covers all four environmental load groups — climatic, mechanical, electrical and chemical — with powered monitoring and combined temperature-vibration testing available. Send us the mounting location and the customer standard, and we will look up the severity matrix in the corresponding part first, then confirm equipment capability.
Related pages for this question
Last updated Technical criteria follow the current standards and the agreed scope; please confirm the specific project with the lab.
