PSA B21 7120 Environmental Technical Specifications - Mechanical Specifications of Electrical and Electronic Equipment

The “PSA B21 7120 Environmental technical specifications - Mechanical specifications of electrical and electronic equipment” standard, developed by the French car manufacturer PSA Group, which is now part of Stellantis, describes the following:

• Mechanical environmental conditions in which the electrical and electronic equipment on the vehicle must operate: Assembly and maintenance, current and excessive manipulations, as well as vibrational stresses due to road use.
• The necessary test methods and procedures, and the required results, to ensure the durability of this type of equipment in its environment.

This standard forms the basis for specifying environmental conditions in equipment specifications. When preparing a specification, the tests to be performed (indicated by their labels) should be selected, and reference should be made to this standard, specifying the required level of enforcement and, if necessary, the degraded operating modes.

Each device has the precise specifications to complete the tests specified in this standard. General requirements for environmental testing of electrical and electronic equipment in vehicles are listed in the standard “PSA B21 7100 General requirements for environmental testing of electrical and electronic equipment in vehicles”. General test environment requirements for ambient temperature, relative humidity, voltage, pressure, and tolerances are as given in the PSA B21 7100 standard. The equipment under test is generally tested individually, within the limits of the mounting requirements on the vehicle. Specific test requirements are defined in the relevant technical specification. The application guide for testing on the equipment is included in the table provided within the standard.

Essentially, the PSA B21 7120 standard forms part of a series of norms regulating environmental requirements for electrical and electronic equipment in vehicles. This standard focuses on the mechanical environmental tests that automotive electrical and electronic components must withstand. It ensures that devices such as sensors, control units, wiring harnesses, connectors, and other electronic subassemblies remain functional and reliable under the demanding mechanical stresses encountered in vehicle operation.

The key areas covered in this standard are:

• Vibration tests:
• Sinusoidal vibrations
• Random vibrations
• Special tests for body-mounted or conductive equipment.
• Shock and impact tests:
• mechanical shocks
• Free falls or collisions
• Balancing (pendulum or oscillation) tests for devices with conductive output.
• Connector and cabling integrity:
• Tensile (pull-out) tests on conductors and connectors (referring to relevant standards such as B21 7050 for connector specifications)
• Testing of terminals and connections for withstand voltage under conditions.
• Other mechanical durability tests:
• Resistance testing against mechanical loads during transportation, installation, and use.

The PSA B21 7120 standard partially replaces previous standards such as PSA B21 7090.

Modern vehicles rely heavily on electronic systems for everything from engine management and infotainment to advanced driver assistance systems. Mechanical stresses such as road vibrations, bumps, or engine movement can cause failures if components are not robustly designed. The PSA B21 7120 standard helps mitigate these risks by defining rigorous, repeatable testing procedures that simulate real-world conditions throughout the vehicle's lifespan.

Compliance with such standards is generally mandatory for companies that are suppliers to the PSA/Stalantis group, contributing to overall vehicle reliability and reducing warranty issues. Specifically, this standard focuses on mechanical robustness in automotive electronics.

The importance of the PSA B21 7120 standard stems from its critical role in ensuring the reliability, safety, and durability of modern automotive electronics under real-world mechanical stresses. This standard is considered important for the following reasons:

• It ensures reliability in demanding automotive conditions: Vehicles are constantly subjected to mechanical stresses, including:
• Vibrations from roads, engines, and suspension.
• Shocks from potholes or bumps
• Tensile forces applied to connectors and cables during assembly or use.

Without rigorous testing, these can lead to failures such as loose connections, cracked circuits, or component fatigue. This standard defines the following testing methods:

• Sinusoidal and random vibrations
• mechanical shocks
• Free falls
• Pendulum (balancing) pulses
• Tensile tests on conductors.

These tests simulate the conditions a vehicle will be exposed to throughout its lifespan, preventing malfunctions during service.

• It enhances vehicle safety: Electronic systems control vital functions such as those listed below:
• Braking System (ABS)
• airbags
• Engine management
• Advanced driver assistance systems (ADAS)

A mechanical failure in these systems can compromise safety. By requiring robust mechanical verification, it helps reduce the risk of failures from standard vibration or shock, contributes to overall vehicle safety, and reduces the potential for accidents caused by electronic malfunctions.

• Mandatory for Stellantis suppliers: Compliance with the B21 7120 standard is generally mandatory for suppliers providing electrical/electronic components to Stellantis brands. Suppliers must verify parts against these standards through independent testing, usually project-specific. Non-conformity may lead to disqualification of parts and loss of contract or warranty claims.
• It reduces costs and improves quality: Early detection of mechanical weaknesses through standardized testing reduces warranty repairs, recalls, and customer dissatisfaction.

In an industry where electronic components account for nearly 40 percent of a vehicle's value, such standards support high quality ratings for Stellantis vehicles and are consistent with broader automotive quality systems like IATF 16949.

In short, the PSA B21 7120 standard is important because it directly addresses mechanical stress, one of the primary failure modes in automotive electronics, which helps deliver safer and more reliable vehicles while also strengthening supplier responsibility in a highly competitive industry.

For many years, our organization, with its competent and experienced staff, has been understanding the needs of its customers, providing the advanced testing services they require, and assisting them in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services to businesses in accordance with the "PSA B21 7120 Environmental technical specifications - Mechanical properties of electrical and electronic equipment" standard.