This Regulation provides uniform provisions for approval of vehicles of categories M₁–M₃ and N₁–N₃ equipped with electric traction chain powertrain retrofit systems to be converted into pure electric vehicles (EV) or Hydrogen Fuel Cell Vehicles (HFCV). Retrofit system manufacturers must submit applications including descriptions of the retrofit system, original parent vehicle, modifications, compliance verification, application range, installed samples, authorized installers, and conversion plates. Type approval requires meeting general requirements for design, construction, durability, and failure communication, plus specific requirements in Annexes 5A for EVs and 5B for HFCVs. Only authorized installers may perform conversions, and manufacturers must provide installation documents and end-user manuals.

This commented working draft establishes uniform provisions for approving vehicles of categories M and N intended to be converted into pure electric vehicles (EV) or Hydrogen Fuel Cell Vehicles (HFCV) with electric powertrain retrofit systems. The regulation covers retrofit system approval, vehicle approval, application range, installer authorization, and conformity of production. Requirements address electromagnetic compatibility, braking, power measurement, rechargeable energy storage systems, mass and dimensions, and compliance with relevant UN Regulations including UN R10, UN R13, UN R85, and UN R100. The documents includes comments from France and RME.

RME views: Vehicles were on the road before UN R155 came into force. Retrofitting extends vehicle life in line with climate action and circular economy objectives. Retrofitters must be responsible only for components involved in the transformation and any parts they add or modify, not for original vehicle components. A risk management demonstration dossier limited to the transformed system must be included in transformation approval applications. If the origin vehicle is not R155-approved, retrofitters may provide the dossier without laboratory tests. If R155-approved, authorities decide on compliance, requiring laboratory tests if needed. Manufacturers’ data are not accessible to retrofitters. The application of cyber security provisions (i.e., UN R155 compliance) should be delayed by two years from the entry-into-force of the new regulation for the approval of EC/HFCV retrofit systems and revisions to UN R155 should also provide two-year transitional provisions before the application to the retrofit regulation.

CITA presented PTI-42-02 to link the PTI informal group’s work to the approval of the EU Roadworthiness Package. FSD proposed work to introduce PTI provisions into UN Regulations under the 1958 Agreement. Japan, Russia, and FSD provided brief updates on the use of diagnostic devices to access to in-vehicle data. CITA updated the group on its views concerning PTI for ADS vehicles. CITA explained GRVA/2025/43, GRVA/2025/44, GRVA/2025/34, and GRVA-23-18/Rev.1 on Electromechanical Braking and Parking Lock Devices which will be considered by WP.29 in March.

The eighth meeting of the Informal Working Group on EV/HFCV Retrofit Systems is scheduled for Tuesday 21st April 2026. The agenda includes coordination and organization of work with reference to GRPE-92-14, EVHFCV-02-02, GRPE-93-22-Rev.1, GRSP-78-17, GRVA-24-07, and GRPE-94-06, electrical safety review, cybersecurity, braking, EMC, and UN draft documentation review. Future meetings are planned for 11th June, 2nd July, and 9th September, with hybrid and online formats.