UN R156 Base text (01 series) · UNECE Regulation No. 156 (ECE R156) — Uniform provisions concerning the approval of vehicles with regards to software update and software updates management system.
UN R156 — 01 series of amendments
Changes from 00 series of amendments
- What changed
- Paragraph 7.1.1.3. adds a process to assign a dedicated RXSWIN for every Regulation No. X type approval to which the vehicle manufacturer executes software updates. These updates are to type approval relevant software of the Electronic Control System contributing to the UN Regulation No. X type approval relevant characteristics.
- Paragraph 7.1.4. covers software updates to vehicles approved to the 01 series of amendments and already registered in the market. The vehicle manufacturer must not execute them unless every Regulation No. X type approval assessed in the paragraph 7.1.1.9. process has an assigned RXSWIN.
- Paragraph 13. adds transitional provisions with the dates 1 September 2028 and 1 September 2030 for type approvals to the original version.
- Why
- Certain Contracting Parties considered it necessary to mandate the use of the RXSWIN concept in UN R156, to avoid discrepancies between manufacturers.
- Benefits of RXSWIN include a clear indication to authorities of changes to the software that is relevant to the approval.
- The proposal gives September 2028 for new types and September 2030 for all types, to permit sufficient lead time to transform the current SUMS.
Q1What changed37 changes
New RXSWIN process (para. 7.1.1.3.)
Paragraph 7.1.1.3. adds a process to assign a dedicated RXSWIN for every Regulation No. X type approval to which the vehicle manufacturer executes software updates. These updates are to type approval relevant software of the Electronic Control System contributing to the UN Regulation No. X type approval relevant characteristics. The former paragraphs 7.1.1.3. to 7.1.1.12. have new numbers 7.1.1.4. to 7.1.1.13.
Software updates to registered vehicles approved to the 01 series (para. 7.1.4.)
New paragraph 7.1.4. covers software updates to vehicles approved to the 01 series of amendments and already registered in the market. These updates need an RXSWIN assigned to every Regulation No. X type approval assessed during the process in paragraph 7.1.1.9. Otherwise, the vehicle manufacturer must not execute them. The former paragraphs 7.1.4. to 7.1.4.2. have new numbers 7.1.5. to 7.1.5.2.
Requirements for RXSWIN (para. 7.2.1.2.)
Paragraph 7.2.1.2. now reads “Requirements for RXSWIN:”. Before, it read “Where a vehicle type uses RXSWIN:”.
RXSWIN items in Annexes 1 and 2
Annex 1 has a new item 9.5. that reads “Identification and accessibility of RXSWIN”. Item 9.5.1. covers how to read any RXSWIN, or the relevant software version(s) in the case where the RXSWIN is not held on the vehicle. Item 9.5.2. covers how to access the information from the auditable register of all software versions relevant to any RXSWIN. Annex 2 has new items 9. and 10. with the same two texts. The old items 9. to 16. of Annex 2 are now items 11. to 18.
Transitional provisions (paras. 13.1. to 13.6.)
From the 01 series’ official date of entry into force, Contracting Parties applying this Regulation must not refuse to grant or accept its type approvals. As from 1 September 2028, Contracting Parties applying this Regulation need not accept type approvals to the original version first issued after 1 September 2028. Until 1 September 2030, Contracting Parties applying this Regulation must accept type approvals to the original version first issued before 1 September 2028. As from 1 September 2030, Contracting Parties applying this Regulation need not accept type approvals to the original version. Despite paragraphs 13.2. and 13.4., Contracting Parties applying this Regulation must continue to accept original-version approvals for vehicles not affected by the 01 series changes. Contracting Parties applying this Regulation must continue to grant extensions of existing approvals to the original version.
Q2Why it changed
- Proposed by
- Informal Working Group on Cyber Security and (Over-the-Air) Software Updates
- Working party
- GRVA, 22nd session (June 2025)
Reasons
The proposal says that the current UN R156 does not mandate the use of an RXSWIN, but sets certain requirements for when one is used. Certain Contracting Parties considered it necessary to mandate the use of the RXSWIN concept in UN R156, to avoid discrepancies between manufacturers.
Sources (2)
“The current provisions of UN Regulation No. 156 (UN R156) do not mandate the use of an RXSWIN, although they do stipulate certain requirements for when one is used.”
“certain Contracting Parties considered it necessary to mandate the use of the RXSWIN concept in UN R156 to avoid discrepancies between manufacturers and enact the benefits that it provides.”
Benefits of RXSWIN include a clear indication to authorities of changes to the software that is relevant to the approval. RXSWIN also supports compliance and market surveillance activities. A majority of manufacturers applying UN R156 use RXSWIN, but it is not universally implemented across the industry.
Sources (2)
“There are certain benefits to using RXSWIN, such as providing authorities with a clear indication of changes to the software that is relevant to the approval and supporting compliance / market surveillance activities.”
“Whilst RXSWIN is used by a majority of manufacturers applying UN R156, it is not universally implemented across the industry”
Using an RXSWIN may be an unnecessary burden if the manufacturer does not plan to update the software in connection with a particular system Regulation. Therefore, the RXSWIN requirement does not apply to a Regulation that is not on the manufacturer's list of Regulations potentially affected by software updates.
Sources (2)
“It is recognised that it may be an unnecessary burden to use an RXSWIN if the manufacturer does not plan to update the software in connection with a particular system Regulation.”
“the requirement for an RXSWIN does not apply if UN Regulation No. X is not part of the list of Regulations checked by the manufacturer as potentially affected by software updates.”
Not all manufacturers already apply the necessary processes to implement the RXSWIN concept. In the original version of UN R156, the means to identify software pertinent to Regulations was left open to the manufacturer to define.
Sources (2)
“Not all manufacturers already apply the necessary processes to implement the RXSWIN concept.”
“In the original version of UN R156, the means to identify software pertinent to Regulations was left open to the manufacturer to define.”
Manufacturers that do not already use RXSWIN will need time to identify and allocate RXSWIN to vehicles. This may become complex where a relationship with a supplier does not provide for the required information flow and new contractual arrangements are needed. For these reasons, the proposal gives September 2028 for new types and September 2030 for all types, to permit sufficient lead time.
Sources (3)
“For manufacturers that do not already use RXSWIN, time will be needed to identify and allocate RXSWIN to vehicles.”
“This may become complex where a relationship with a supplier does not provide for the required information flow and new contractual arrangements are needed.”
“For these reasons, the proposal for new types from September 2028, and for all types from September 2030, in order to permit sufficient lead time to transform the current SUMS and introduce RXSWINs”
Document trail
- 2025-04ProposalECE/TRANS/WP.29/GRVA/2025/28Proposal for a new series of amendments to UN Regulation No. 156
- —Working party adoptsECE/TRANS/WP.29/GRVA/22Session report, para. 38
- 2025-08Sent to WP.29ECE/TRANS/WP.29/2025/142Text that GRVA sent to WP.29 and AC.1
- 2025-11WP.29 adoptsECE/TRANS/WP.29/1188Adopted at the 197th session (session report, para. 110)
- 2026-06-04In forceC.N.237.2026.TREATIES-XI.B.16.156UN depositary notification
Q3Who is affected
Vehicle manufacturer
- Assign a dedicated RXSWIN for every Regulation No. X type approval whose type approval relevant software you update.
- Update registered 01 series vehicles only after every Regulation No. X type approval assessed under paragraph 7.1.1.9. has an RXSWIN.
- In the type approval application, give the new Annex 1 items 9.5.1. and 9.5.2. on identification and accessibility of RXSWIN.
- Plan for paragraph 13.2.: original-version approvals first issued after 1 September 2028 need not be accepted.
- Plan for paragraph 13.4.: from 1 September 2030, original-version approvals need not be accepted, except as paragraph 13.5. says.
Component supplier
- No direct action for this role.
Technical service / Approval authority
- Be ready to check the RXSWIN process of new paragraph 7.1.1.3.
- Be ready for the new RXSWIN information in Annex 1 items 9.5.1. and 9.5.2.
- Use the new items 9. and 10. on RXSWIN in the communication form.
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ⓘ This report gives advice only. It is not legal or type-approval advice.