FMVSS

📖 YOUCANIC Automotive Glossary

FMVSS (Federal Motor Vehicle Safety Standards) are the federal regulations established by NHTSA (National Highway Traffic Safety Administration) that set minimum safety performance requirements for motor vehicles and vehicle equipment sold in the United States. FMVSS standards cover crashworthiness (airbags, seatbelts, structure), crash avoidance (lighting, mirrors, braking), and post-crash survivability (fuel system integrity, emergency egress). Relevant FMVSS for DIYers include FMVSS 108 (lighting), FMVSS 135 (braking), FMVSS 138 (TPMS), FMVSS 126 (ESC), FMVSS 111 (rearview visibility), and FMVSS 214 (side impact protection).

Understanding FMVSS helps DIYers appreciate why certain systems are mandatory and why modifications to safety equipment (removing airbags, disabling ESC permanently, installing non-compliant lighting) may be illegal and dangerous. FMVSS compliance is tested and certified by the manufacturer at the time of production. Repairs should maintain FMVSS compliance — for example, replacement headlights should meet FMVSS 108, and brake components should meet FMVSS 135 performance requirements.