UN R13 Supplement 4 (14 series) · UNECE Regulation No. 13 (ECE R13) — Uniform provisions concerning the approval of vehicles of categories M, N and O with regard to braking.
UN R13 — Supplement 4 to the 14 series of amendments
Supplement 3 → 4
- What changed
- This supplement adds the words “regardless of its means of activation” to paragraph 5.2.1.31. on the emergency braking signal.
- An example of a means of activation is an auxiliary control as specified in paragraph 5.2.1.2.4.
- Why
- The proposal aimed to align UN Regulation No. 13 with provisions that GRVA had already approved for UN Regulation No. 13-H.
- The proposal also aimed at a consistent interpretation of the activation conditions for the Emergency Stop Signal (ESS).
- This means that the application of the service braking system through the Electronic Parking Brake (EPB) control can generate the ESS.
Q1What changed1 change
Emergency braking signal and the means of activation of the service braking system (para. 5.2.1.31.)
Paragraph 5.2.1.31. applies to vehicles with the means to indicate emergency braking. As before, only the application of the service braking system can switch the emergency braking signal on and off, when the paragraph’s conditions are met. This supplement adds the words “regardless of its means of activation” after “the application of the service braking system”. An example of a means of activation is an auxiliary control as specified in paragraph 5.2.1.2.4.
Q2Why it changed
- Proposed by
- Experts from OICA and CLEPA
- Working party
- GRVA, 24th session (January 2026)
Reasons
The proposal aimed to align UN Regulation No. 13 with provisions that GRVA had already approved for UN Regulation No. 13-H (ECE/TRANS/WP.29/GRVA/2025/45/Rev.1).
Source
“The representative of OICA presented GRVA-24-08 proposing to align the provisions of UN Regulation No. 13 with those already approved by GRVA (ECE/TRANS/WP.29/GRVA/2025/45/Rev.1) for UN Regulation No. 13-H.”
An auxiliary control can be an Electronic Parking Brake (EPB) control, on a vehicle with an electronic parking brake system. It is common practice to apply the service braking system through the EPB control.
Sources (2)
“by means of an auxiliary control, which could be an Electronic Parking Brake (EPB) control in case of an electronic parking brake system”
“Therefore, the application of the service braking system via the EPB control is common practice.”
The proposal aimed to clarify the existing text. The aim was an aligned and consistent interpretation of the activation conditions for the Emergency Stop Signal (ESS). This means that the application of the service braking system through the EPB control can generate the ESS.
Sources (2)
“The proposal aims to clarify the existing text in order to ensure an aligned and consistent interpretation of the activation conditions for an Emergency Stop Signal (ESS)”
“means the ESS can be generated by application of the service braking system via the EPB control”
Document trail
- —ProposalGRVA-24-08Proposal by experts from OICA and CLEPA
- —Working party adoptsECE/TRANS/WP.29/GRVA/24GRVA session report, para. 77
- 2026-04Sent to WP.29ECE/TRANS/WP.29/2026/75Text that GRVA sent to WP.29 and AC.1
- 2026-06-24WP.29 adoptsECE/TRANS/WP.29/1192Adopted at the 199th session (session report, para. 103)
- PendingIn forceDate not yet known
Q3Who is affected
Vehicle manufacturer
- Compare your emergency braking signal logic with the new text of paragraph 5.2.1.31.
- Make sure only service braking, whatever its means of activation, generates the emergency braking signal under paragraph 5.2.1.31. conditions.
- Test the emergency braking signal also with service braking through an auxiliary control (paragraph 5.2.1.2.4.).
- Update your documents that quote the text of paragraph 5.2.1.31.
Component supplier
- Make sure that your brake control software applies the paragraph 5.2.1.31. rule to each means of service brake activation.
- If your Electronic Parking Brake (EPB) control applies the service braking system, test the emergency braking signal with it.
- Give the vehicle manufacturer updated system documents for paragraph 5.2.1.31.
Technical service / Approval authority
- Compare your test and assessment documents for the emergency braking signal with the new text of paragraph 5.2.1.31.
- When you assess the emergency braking signal, include service braking through an auxiliary control (paragraph 5.2.1.2.4.).
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ⓘ This report gives advice only. It is not legal or type-approval advice.
More UN R13 change reports
- 15 series — Supplement 3
- 15 series — Supplement 2
- 15 series — Supplement 1
- 15 series — Base text
- 14 series — Supplement 3
- 14 series — Supplement 2
- 14 series — Supplement 1
- 14 series — Base text
- 13 series — Supplement 7
- 13 series — Supplement 6
- 13 series — Supplement 5
- 13 series — Supplement 4
- 13 series — Supplement 3
- 13 series — Supplement 2
- 13 series — Supplement 1
- 13 series — Base text
- 12 series — Supplement 9
- 12 series — Supplement 8
- 12 series — Supplement 7
- 12 series — Supplement 6
- 12 series — Supplement 5
- 12 series — Supplement 4
- 12 series — Supplement 3
- 12 series — Supplement 2
- 12 series — Supplement 1
- 12 series — Base text
- 11 series — Supplement 23
- 11 series — Supplement 22
- 11 series — Supplement 21
- 11 series — Supplement 20
- 11 series — Supplement 19
- 11 series — Supplement 18
- 11 series — Supplement 17
- 11 series — Supplement 16