UN R143 Supplement 2 (00 series) · UNECE Regulation No. 143 (ECE R143) — Uniform provisions concerning the approval of Heavy Duty Dual-Fuel Engine Retrofit Systems (HDDF-ERS) to be installed on heavy duty diesel engines and vehicles.
UN R143 — Supplement 2 to the 00 series of amendments
Supplement 1 → 2
- What changed
- A dual-fuel engine retrofit system capable of operating on vehicles equipped with an ADS must send a signal to the ADS about the engine mode.
- Whilst an ADS feature is active, the system must signal the ADS when engine operation is forced to diesel mode as required by paragraph 4.3.
- During dual-fuel operation, a clear signal about a malfunction detected by the dual-fuel ECU must inform the driver and/or the ADS.
- Why
- The proposal introduces changes that are necessary to include vehicles with Automated Driving Systems in the existing Regulation.
- Driver messages and warnings change, so that the requirements suit vehicles with and without a human driver.
Q1What changed11 changes
Dual-fuel operating mode indicator and mode signal to the ADS (para. 4.4.1.)
A dual-fuel engine retrofit system must have a visual indicator that shows the driver (if applicable) the engine mode (dual-fuel mode or diesel mode). The words "(if applicable)" are new. A new sentence applies to a dual-fuel engine retrofit system capable of operating on vehicles equipped with an ADS. Such a system must send a signal to the ADS that shows the mode under which the engine operates (dual-fuel mode or diesel mode).
Warning and ADS signal when the engine is forced to diesel mode (para. 4.4.1.1.)
The dual-fuel system must warn the driver (if applicable) when the engine operation is forced to diesel mode as required by paragraph 4.3. The warning uses the dual-fuel mode indicator or an audio signal (or both). The words "(if applicable)" are new. A new sentence applies whilst an ADS feature is active. The dual-fuel system must then send a signal to the ADS when the engine operation is forced to diesel mode as required by paragraph 4.3.
Signal for a malfunction detected by the dual-fuel ECU (para. 7.1.)
During dual-fuel operation, if the dual-fuel ECU detects a malfunction, a clear signal must inform the driver and/or the ADS about the situation. Before this supplement, a clear visual or acoustic signal had to inform the driver about the situation.
Reference to R.E.3 in footnote 1 (para. 1.1.)
Footnote 1 to paragraph 1.1. refers to the Consolidated Resolution on the Construction of Vehicles (R.E.3.) and now gives document ECE/TRANS/WP.29/78/Rev.8. Before this supplement, it gave paragraph 2 of document ECE/TRANS/WP.29/78/Rev.5. The footnote now gives the address https://unece.org/transport/vehicle-regulations/wp29/resolutions.
Q2Why it changed
- Proposed by
- Task Force on Automated Vehicles Regulations Screening (AVRS)
- Working party
- GRPE, 94th session (March 2026)
Reasons
The proposal introduces changes that are necessary to include vehicles with Automated Driving Systems in the existing Regulation.
Source
“The document introduces changes required to incorporate vehicles with Automated Driving Systems into the existing Regulation.”
The reference to R.E.3 is updated to include vehicles equipped with an ADS in the scope. Revision 8 of R.E.3 introduces vehicle categories X and Y. Vehicles of these categories cannot be driven manually above 6 km/h.
Sources (2)
“Reference to the Consolidated Resolution on the Construction of Vehicles (R.E.3.) is updated to include ADS equipped vehicles in the scope.”
“Vehicle categories X and Y are introduced in Revision 8 of R.E.3, prepared by the Task Force on Automated Vehicle Categorisation (TF-AVC) under GRSG and GRVA, and are not capable to be driven manually above 6 km/h.”
Driver messages and warnings change, so that the requirements suit vehicles with and without a human driver.
Source
“Driver messages and warnings are changed to make the requirements suitable for vehicles with and without a human driver.”
Document trail
- 2026-01ProposalECE/TRANS/WP.29/GRPE/2026/22Proposal by the Task Force on AVRS
- —Working party adoptsECE/TRANS/WP.29/GRPE/94GRPE session report, para. 45
- 2026-04Sent to WP.29ECE/TRANS/WP.29/2026/152Text that GRPE 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
- Make sure systems capable of operating on ADS-equipped vehicles signal the engine mode (dual-fuel or diesel) to the ADS.
- Whilst an ADS feature is active, make sure the ADS is signalled when diesel mode is forced under paragraph 4.3.
- During dual-fuel operation, make sure a clear signal informs the driver and/or the ADS of malfunctions the dual-fuel ECU detects.
Component supplier
- No direct action for this role.
Technical service / Approval authority
- Be ready to check the engine mode signal to the ADS for systems capable of operating on ADS-equipped vehicles.
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ⓘ This report gives advice only. It is not legal or type-approval advice.