China's Vehicle Lighting Regulation GB 4785 Under Revision – New Rules for ADB, Matrix Headlights, and Intelligent Signal Displays
China's fundamental vehicle lighting regulation, GB 4785, is undergoing a major revision to address the rapid advancement of intelligent lighting technologies.
Known as the "foundational law" of automotive lighting, GB 4785 governs the installation requirements, geometric visibility, chromaticity standards, and logic sequences for vehicle lighting and signaling devices. The new revision – formally titled "Requirements for Installation of External Lighting and Light-Signaling Devices for Motor Vehicles and Trailers" (Plan No. 20262535-Q-339) – is currently in the drafting stage with a 16-month project cycle and will fully replace the 2019 version.
What's Changing?
The most notable shift in this revision is the composition of the drafting committee – for the first time, intelligent driving and new energy leaders have joined the process, including Shanghai Motor Vehicle Inspection Certification & Technology Innovation Center, China Automotive Technology and Research Center, Shenzhen Yinwang Intelligent Technology, SAIC Volkswagen, and BYD Auto.
This combination of testing institutions, traditional joint ventures, domestic NEV manufacturers, and autonomous driving solution providers signals that the new standard will directly address technologies not fully covered by the 2019 version – including LED matrix systems, Adaptive Driving Beam (ADB) headlights, pixel projection, and intelligent driving status signal lamps.
Why the Revision Is Needed Now
GB 4785-2019, implemented in July 2020, has been outpaced by rapid technological advances:
Light Source Evolution: LED lighting has become mainstream, with laser headlights and MicroLED pixel modules now entering production as standard configurations
Functional Advancements: ADB, matrix headlamps, ground projection welcome lights, and lane guidance light carpets have moved from concept to mass production
Signaling Innovation: L2+ and L3 autonomous vehicles are increasingly adopting "intelligent driving status lamps" and "taillight light language" to communicate with surrounding traffic – but current national standards have not yet incorporated these into the legal lighting catalog, leaving both aftermarket modifications and OEM-developed solutions in a regulatory gray area
International Alignment: UN WP.29 regulations on adaptive forward lighting and projection symbols continue to evolve, requiring domestic mandatory installation rules to keep pace
What to Expect
Industry consensus suggests the next version of GB 4785 will establish clear boundaries for intelligent lighting installation – for example, projection patterns limited to low/high beam functions, white light only, not crossing lane boundaries, and automatic dimming or shutdown at specific speeds or when nearby vehicles are detected.
Timeline
April 2026: Plan issued, public comment period ended, drafting stage underway
Next 16 months: Draft for comments → Review → Approval
Expected H2 2027 – early 2028: New version published, with transition period to replace 2019 version
Implications for the Aftermarket
For the aftermarket, the revised regulation will provide clearer enforcement standards for modifications. Unauthorized installations such as "small blue lights," color-changing DRLs, non-compliant through-type taillights, and illegally elevated high-beam modules – already illegal under the current GB 4785-2019 – will face even more detailed inspection and enforcement under the new rules.
Industry Significance
This regulatory update will better align China's lighting standards with the rapid evolution of automotive lighting technology, providing legal certainty for OEMs and component suppliers while ensuring road safety in the intelligent driving era.
