UN R13 Base text (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 — 14 series of amendments
Changes from 13 series of amendments (supplement 2)
- What changed
- New paragraph 5.2.1.35. sets special additional requirements for power-driven vehicles equipped with an electrical transmission braking system (ETBS).
- Annex 18 now covers Electronic System(s) as well as complex electronic control systems, and a new appendix gives a model assessment form.
- From the 14 series' entry into force, ETBS vehicle types are approved only if they meet the 14 series (para. 12.1.2.).
- Why
- The proposal sought to permit braking systems that rely purely on stored electrical energy, controlled by the driver, to give the prescribed service braking performance.
- The proposal sees the security of the electrical energy as the most significant concern and sets out requirements for an energy management system.
- The Annex 18 changes seek the same assessment procedures for electronic control systems and complex electronic control systems.
Q1What changed342 changes
Electrical transmission braking systems: definitions and special requirements (paras. 2.21.4., 2.45. to 2.56., 5.2.1.35.)
New paragraph 2.54. defines the “Electrical Transmission Braking System” (ETBS). In an ETBS, the service braking force and transmission depend exclusively on the use, controlled by the driver, of energy from electrical storage devices. Other new definitions in paragraphs 2.45. to 2.56. include “Brake demand value”, “Electrical storage device”, “Electrical supply” and “Energy Management System”. Paragraph 2.21.4. now refers to an electrical storage device (for example battery or capacitor) instead of the traction battery. New paragraph 5.2.1.35. sets special additional requirements for power-driven vehicles equipped with an ETBS, including an energy management system and yellow and red warnings. Within 60 seconds of the acoustic warning (para. 5.2.1.13.1.2.), an automatic function must progressively reduce the speed so it cannot exceed 20 km/h.
Energy reserve warning and other general braking requirements (paras. 5.2.1.2.7.2. to 5.2.1.29.4.4.)
Paragraph 5.2.1.13.1. now refers to an “energy reserve” instead of an “energy reservoir”, and also to the state of an electrical storage device, as relevant. For ETBS vehicles, paragraph 5.2.1.13.1.2. adds an acoustic signal: within 60 seconds of the red warning, or at the next service brake application if earlier. Paragraph 5.2.1.13.2. requires ETBS vehicles to have an indicator of the effect of ageing on each electrical storage device. This does not apply to a traction battery that also has the function of an energy storage device. Paragraphs 5.2.1.5., 5.2.1.16. and 5.2.1.26.3. now also cover electrical supplies, electrical auxiliary equipment and ETBS, respectively. Paragraph 5.2.1.18. now refers to a vehicle authorized to tow O3 or O4 trailers “which is equipped with a compressed-air braking system”.
Reference braking forces and roller brake tests (paras. 2.31., 5.1.4.5.1., 5.1.4.5.3., 5.1.4.6.)
Paragraph 2.31. now relates “reference braking forces” to brake actuator pressure or brake demand value, respectively. Paragraph 5.1.4.5.1. now also covers the data of an electrical transmission braking system for the functional and efficiency test. New paragraph 5.1.4.6.2. sets how reference braking forces are defined for an ETBS on a roller brake tester. The brake demand values must be displayed on the vehicle and easily readable from the driver's seat during the roller brake test. New paragraph 5.1.4.5.3. requires the manufacturer to describe at type approval how to check that the detection means for three ETBS warnings are operational. Former paragraphs 5.1.4.6.2. and 5.1.4.6.3. are now paragraphs 5.1.4.6.1.1. and 5.1.4.6.1.2.
ETBS tests and approval form entries (Annexes 2, 4, 7 Part D and 13); Annex 8 title
New Part D of Annex 7 sets requirements for the performance of electrical storage devices and the capacity of the electrical supply. Under Part D, paragraph 1.2.1., the electrical storage devices must give at least secondary braking performance at the ninth braking, after eight full actuations. Each full actuation lasts at least 8.0 seconds, with an interval of at least 5.0 seconds that the vehicle manufacturer specifies. For the Annex 4 hot performance test, any system or function compensating for brake performance lost to heat fade must be inoperative. Annex 2 adds a new item 17 with information on ETBS vehicles, and former items 17 to 26 become items 18 to 27. In Annex 13, each full actuation of an ETBS in paragraph 5.1.1.4. must be as defined in Annex 7, Part D, paragraph 1.2.3.3.
Type II test for brake linings (Annex 15, paras. 4.5. to 4.5.2.)
Annex 15, paragraph 4.5.1. now refers to the Type-II test as required by Annex 4, paragraph 1.6 or 1.8.2.5 (b). These tests use a six per cent slope and a seven per cent slope, respectively. A new text in paragraph 4.5.2. covers M3 and N3 vehicles that need a Type-IIA test and meet it only by Annex 4, paragraph 1.8.2.5. Brake linings for these vehicles must be tested to the procedure of Annex 4, paragraph 1.8.2.5 (b).
Safety of electronic control systems (Annex 18 and its new appendix)
Annex 18 now covers Electronic System(s) (paragraph 2.3.) as well as complex electronic control systems (paragraph 2.4.), and its title no longer says “complex”. New definitions include “The System” (paragraph 2.1.) and “Control strategy” (paragraph 2.10.). The Technical Service assesses the documentation package for four points, such as that “The System” is designed not to induce safety critical risks under fault conditions. The formal documentation package must remain available for at least 10 years after production of the vehicle is definitely discontinued. The check of the reaction of “the system” to a failure in an individual unit is no longer at the discretion of the type approval authority. A new appendix gives a model assessment form for electronic, and/or complex electronic, control systems.
Transitional provisions for the 14 series (paras. 12.1.1. to 12.2.2.)
From the entry into force of the 14 series, no Contracting Party may refuse to grant or accept 14 series type approvals. From that date, type approvals for a vehicle with an ETBS are granted only if the vehicle type meets the 14 series. From 1 September 2028, Contracting Parties need not accept preceding-series approvals first issued after that date for vehicle types with an electronic braking control system. From 1 September 2030, Contracting Parties need not accept preceding-series approvals, other than for vehicles not affected by the 14 series changes (para. 12.1.5.). Contracting Parties may grant approvals to any preceding series and must continue to grant extensions of existing approvals (paras. 12.2.1. and 12.2.2.).
Q2Why it changed
- Proposed by
- Special interest group on electrical braking systems (electrical transmission braking systems); expert from the United Kingdom of Great Britain and Northern Ireland (Annex 18); experts from the Netherlands (Annex 15)
- Working party
- GRVA, 19th session (June 2024)
Reasons
The proposal sought to permit braking systems that rely purely on stored electrical energy, controlled by the driver, to give the prescribed service braking performance. It was prepared so that electrical braking systems give at least the same level of safety and security as the systems known today. New terms relate to the changed energy medium: an “electrical storage device” is analogous to a “reservoir/accumulator” in pneumatic or hydraulic braking systems.
Sources (4)
“The proposal seeks to permit the use of braking systems that rely purely on the use of stored electrical energy, controlled by the driver, to provide the service braking performance prescribed in this Regulation.”
“The proposal has been prepared to ensure that electrical braking systems will provide at least the same level of safety and security that is provided by the systems that we know today.”
“New terms have been introduced that relate to the changed energy medium.”
“The term “electrical storage device” is analogous to the term “reservoir/accumulator” in pneumatic/hydraulic braking systems.”
The proposal sees the security of the electrical energy as the most significant concern for this new generation of braking systems. An energy management system gives the driver timely warnings if the stored energy falls too low to meet the prescribed performance criteria. Warnings are also given at any point that the ageing effect could compromise the fulfilment of the requirements. Other vehicle systems rely on electrical power from the same energy reserves as the braking system. With low electrical energy, measures let the braking system and other essential safety systems keep working, or bring the vehicle to a safe halt.
Sources (5)
“The security of the electrical energy is recognised as being the most significant concern for this new generation of braking systems.”
“The energy management system will ensure that, should the stored energy fall to a value at which prescribed performance criteria cannot be met, timely warnings are provided to the driver.”
“warnings provided at any point that the ageing effect could compromise the fulfilment of the requirements of this Regulation”
“It is recognised that other vehicle systems, both essential and optional, will rely on electrical power from the same energy reserves as the braking system.”
“in the event of there being low electrical energy, the braking system, and other essential safety systems, can continue to function, or that the vehicle is brought to a safe halt”
The Annex 18 proposal sought to align the text, where appropriate, with Annex 6 to UN Regulation No. 79. It also sought the same assessment procedures for electronic control systems and complex electronic control systems. During discussions on Annex 6 to UN Regulation No. 79, an inconsistent understanding of the requirements was recognised. Because electronic control systems are increasingly used in braking systems, the proposal explicitly extends the Annex 18 assessment to include both kinds.
Sources (4)
“Align, where appropriate, the text in UN Regulation No. 13 with that of Annex 6 to UN Regulation No. 79 (Steering equipment).”
“Require the same assessment procedures for both electronic control systems and complex electronic control systems.”
“during discussions on the content of the equivalent text of UN Regulation No. 79 (Annex 6), it was recognised that there was inconsistent understanding of the requirements”
“Recognising the increasing use of electronic control systems in braking systems, in addition to complex control systems, the proposal explicitly extends the Annex 18 assessment to include both.”
The transitional provisions were proposed so that the new requirements apply immediately for new technology, for example electro-mechanical braking systems. They also aim to give a period of transition for existing technologies that may be in, or close to, the market. Part II of ECE/TRANS/WP.29/GRVA/2024/25 delays the introduction of the Annex 18 changes by 12 months. This reflects the period over which the special interest group on electromechanical braking had worked to bring forward its proposals.
Sources (3)
“Transitional Provisions are proposed that would see the new requirements applying immediately for new technology (e.g. electro-mechanical braking systems) but provide a period of transition for existing technologies that may be in, or close to the market.”
“The proposal in part II delays the introduction of changes to Annex 18, proposed in ECE/TRANS/WP.29/GRVA/2023/10, by 12-months.”
“This reflects the period over which the special interest group on electromechanical braking has been working to bring forward its proposals.”
Proposer's reason (informal document GRVA-19-11)
The amendment clarifies that Annex 15 must use, when relevant, the Type II test of Annex 4, paragraph 1.8.2.5 (b) for alternative brake linings. Annex 15 did not refer to this test. Paragraph 1.3 of Annex 15 let a Technical Service ask for it, but then the test had to be done twice. The aim is to overcome this double work and to keep a level playing field.
Submitted by Experts from the Netherlands. Working party adoption: ECE/TRANS/WP.29/GRVA/19, para. 76.
Sources (5)
“This amendment is to clarify the need to apply, when relevant, the Type II test as required by Annex 4 paragraph 1.8.2.5 (b) in Annex 15 for alternative brake lining purposes.”
“However, this Annex does not refer to the Type II test as required by Annex 4 paragraph 1.8.2.5 (b).”
“Based on paragraph 1.3 of the same Annex 15 it is possible to demand additional tests according to Annex 4”
“however in such case the test needs to be executed twice”
“To overcome such double work and to ensure a level playing field”
Document trail
- 2023-03ProposalECE/TRANS/WP.29/GRVA/2023/10Proposal on Annex 18 by the expert from the United Kingdom
- 2024-04ProposalECE/TRANS/WP.29/GRVA/2024/25Proposal for a new series of amendments by the special interest group on electrical braking systems
- —Amended in sessionGRVA-19-23Changes to ECE/TRANS/WP.29/GRVA/2024/25 by the Chair of the EMB Special Interest Group and the experts from OICA and CLEPA
- —ProposalGRVA-19-11Proposal on Annex 15 by the experts from the Netherlands
- —Working party adoptsECE/TRANS/WP.29/GRVA/19GRVA session report, paras. 70, 74 and 76
- 2024-09Sent to WP.29ECE/TRANS/WP.29/2024/143Text that GRVA sent to WP.29 and AC.1
- 2024-11WP.29 adoptsECE/TRANS/WP.29/1181Adopted at the 194th session (session report, para. 158)
- 2025-06-12In forceC.N.287.2025.TREATIES-XI.B.16.13UN depositary notification
Q3Who is affected
Vehicle manufacturer
- Plan type approvals of vehicle types with an electrical transmission braking system to the 14 series (para. 12.1.2.).
- Plan for 1 September 2028 and 1 September 2030, the dates in paragraphs 12.1.3. and 12.1.4.
- For ETBS vehicles, describe at type approval how to check that the warning detection means are operational (para. 5.1.4.5.3.).
- For ETBS vehicles, make the reference braking force data available as paragraph 5.1.4.5.1. requires (para. 5.1.4.6.2.2.).
- Provide the energy management system information of paragraph 5.2.1.35.8.3. as part of the Annex 18 documentation.
- Keep your confidential Annex 18 material and analysis data available for 10 years after production is definitely discontinued.
Component supplier
- Design the energy management system to assess the electrical storage devices continuously and, where appropriate, activate the warnings (para. 5.2.1.35.8.1.).
- Give the vehicle manufacturer the energy management system data that paragraph 5.2.1.35.8.3. lists, such as the sensitivity analysis.
- Check if your brake linings for M3 or N3 vehicles fall under the new text of Annex 15, paragraph 4.5.2.
Technical service / Approval authority
- Check the accuracy of the energy management system under all reasonably foreseeable operating conditions (para. 5.2.1.35.8.2.).
- Assess the Annex 18 documentation package to show that “The System” meets the four points (a) to (d).
- Make sure the Annex 18 formal documentation package remains available for at least 10 years after production is definitely discontinued.
- Check the reaction of “the system” to a failure in at least one individual unit, as Annex 18 now requires.
- Check that the electrical supply of ETBS vehicles meets Annex 7, Part D, section 2 (para. 5.2.1.35.12.).
See every change side by side
RegVault customers compare every version of UN regulations, read the consolidated text and download the PDF.
ⓘ 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 4
- 14 series — Supplement 3
- 14 series — Supplement 2
- 14 series — Supplement 1
- 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