Proposal to delete paragraph 1.2.6. excluding e-axle trailers with e-axles providing electric propulsion and/or incorporating an electric regenerative braking system from the scope of UN R13, and add definitions of “e-axle,” “e-axle trailer,” “dynamo function,” and “e-trailer”; add special requirements for power-driven vehicles supporting e-trailer operation, e-axle trailers equipped with dynamo function, and e-trailers of category O; add requirements for electric control lines conforming to ISO 11992-2:²⁰²⁷; specify message support and functional compatibility; and add provisions for electric regenerative braking, dynamo function, and propulsion, including parameters such as retarder torque demand priority, propulsion force limits, overriding mode activation at speeds below 15km/h, and vehicle stability function interaction.

Presentation on electrically propelled and recuperating trailers. The document outlines communication flows between towing vehicles and e-trailers using ISO 11992-2 over ISO 7638-1, involving parameter groups EBS14 (control), EBS28 (energy/state of charge), and EBS29 (status). Key principles include the towing vehicle setting control modes and requesting torque, with trailers reporting capabilities. The document discusses support for maximum three e-axle equipped trailers due to bandwidth limitations, enabling of e-trailer control via CANopen Service Data Objects, and backward compatibility with ISO 11992-2:2014. Amendments to UN Regulation 13 are planned with target entry into force in May 2028.

Proposal to insert provisions on software identification and software updates into UN R13, UN R13-H, UN R79, UN R89, UN R130, UN R131, UN R152, UN R155, UN R156, UN R157, UN R171, UN R175, and UN R178 by adding definitions referencing Consolidated Resolution R.E.3 Annex 7, requiring manufacturers to provide Technical Services with information on hardware and software influencing performance, permitting vehicle manufacturers to apply for new approvals differentiating software versions for registered versus new vehicles, clarifying that production discontinuation does not apply when manufacturers seek approval extensions for software updates of registered vehicles, and amending communication forms to include software identification numbers and related information.

Single N₁ and N₂ vehicles with fluted brake drums for parking brakes cannot be inspected on roller and plate test benches or in test drives. Electric parking brake systems cannot be tested on roller and plate test benches or test drives, and wheels cannot be turned on lifts to inspect for damages or bearing wear. Some vehicles have hydraulic braking systems with brake fluid reservoirs not accessible without dismantling or special tools, requiring removal of covers, fasteners, and screws to access brake fluid for inspection. PTI inspection provisions require updating to address these vehicle design variations.

Proposal to amend para. 2.8 of Annex 8 to add subparagraph (c). The amendment addresses trailers utilizing service braking system energy reserves for automatic brake requirements. Current para. 2.8 includes options (a) and (b) requiring spring brake pressure reduction or corresponding pressure reduction in spring compression chamber. New subparagraph (c) permits alternative designs where combined service braking and parking braking system activation holds a laden trailer on 18 percent gradients at any service brake energy reservoir pressure from 850 kPa to 0 kPa, providing greater realization flexibility while maintaining required holding performance.

Proposal to amend para. 2.8 of Annex 8 to UN R13 to require trailers utilizing service braking system energy reserves to fulfil one of three requirements when uncoupled and park brake control released: pressure in spring brake compression chamber shall reduce to 0 kPa when energy reserves reduce to 280 kPa, pressure reduction in service braking system energy reserve results in corresponding reduction in spring compression chamber pressure, or combined service and parking braking forces shall hold laden trailer as required when service brake energy reservoir reduces from 850 kPa to 0 kPa.

Proposal to amend UN R13, 13-H, 79, 89, 130, 131, 139, 140, 152, 155, 156, 157, 171, 175, and 178 by introducing provisions on software identification and software updates. Amendments add new paragraphs referring to Software Identification Number definitions in Consolidated Resolution R.E.3, require manufacturers to provide Technical Services with information on hardware and software influencing performance, permit vehicle manufacturers to apply for new approvals differentiating software versions for registered versus new vehicles while avoiding test duplication, and modify production discontinuation provisions to exclude cases where manufacturers seek approval extensions for software updates of registered vehicles.

The Informal Working Group on EV/HFCV Retrofit Systems held its seventh meeting on 5th March 2026. The group adopted the provisional agenda, approved minutes of the previous meeting, and acknowledged ongoing activities under GRPE, GRSP and GRVA. Electrical safety review will continue once clarification regarding UN R100 is available. Cybersecurity discussions covered very old vehicles, older vehicles without cybersecurity provisions, and modern vehicles compliant with UN R155. Braking aspects and the structure of the draft UN Regulation were discussed, including vehicle versus system approval approaches and minimum and maximum vehicle age within the regulation’s scope.

Proposal to modify paragraph 5.2.1.31 to clarify that when a vehicle is equipped with means to indicate emergency braking, activation and deactivation of the emergency braking signal shall only be generated by application of the service braking system regardless of its means of activation under the specified conditions.

Proposal to amend paragraph 5.2.1.31. regarding activation and de-activation of the emergency braking signal. When a vehicle is equipped with the means to indicate emergency braking, activation and de-activation of the emergency braking signal shall only be generated by the application of the service braking system regardless of its means of activation when the specified conditions are fulfilled.

Proposal to amend paragraph 5.2.1.31. to specify that when a vehicle is equipped with the means to indicate emergency braking, activation and deactivation of the emergency braking signal shall only be generated by the application of the service braking system regardless of its means of activation when the specified conditions are fulfilled.

Proposal to remove the draft provisions concerning the approval of stability performance under UN R13 and UN R140 for ADS vehicles via demonstration under the safety case provisions of the forthcoming UN Regulation on ADS, and to remove bracket unintentionally retained in the original submission.

The e-Trailer Industry Group reports on discussions regarding electrically propelled and recuperating trailers. ISO 11992-2 Edition 4 is not safely implementable due to incompatibility with current UN regulations, missing PGNs, and risks of malfunction. ISO/TC 22/SC 31/WG 4 launched Edition 5, targeting publication in early 2027. Amendments to UN R13 and UN R100 are being developed in phases, with Phase 1 addressing trailer dynamo function and Phase 2 addressing e-axle trailers. Two workshops with Contracting Parties are planned to establish shared understanding and develop concrete parameter extensions for amending UN Regulations.

Proposal to clarify that the parking brake may be actuated while the vehicle is in motion via actuation of the vehicle’s service braking system by means of an auxiliary control which could be an Electronic Parking Brake (EPB) and to promote consistent interpretation of the activation conditions for an Emergency Stop Signal (ESS), including by application of the service braking system via the EPB control.