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 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.

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 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.