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UN R141 Supplement 2 (01 series) · UNECE Regulation No. 141 (ECE R141) — Uniform provisions concerning the approval of vehicles with regard to their Tyre Pressure Monitoring Systems (TPMS).

UN R141 — Supplement 2 to the 01 series of amendments

Supplement 1 → 2

Adopted at the WP.29 187th sessionEntry into force 2023-01-04
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What changed
  • A TPRS or CTIS must fulfil paragraphs 5.1.2., 5.1.3., 5.4. to 5.6. and Annex 4 to be deemed equivalent for Type Approval to a TPMS.
  • Paragraphs 5.4.1. to 5.4.3., 5.5.6., 5.6.1. and 5.6.1.1. now refer to the TPMS/ TPRS/ CTIS instead of the TPMS.
  • In Annex 4, new paragraphs cover twin wheels (2.1.), check of lamp function (2.3.), refilling according to Figure 2 (2.5.2.) and malfunction detection (2.6.).
Why
  • All requirements for TPRS and CTIS were in Annex 4 only, and the Task Force decided to move them to paragraph 5 of the Regulation.
  • The Annex 5 time/date data were aligned with standard SAE J1939 PGN 65254 due to comments from the ISO Working Group ISO/TC22/SC31/WG4.
  • The expert from CLEPA said that on unladen trailers some lift axles may be lifted automatically, so the test needs enough load.

Q1What changed105 changes

TPRS and CTIS as equivalent to TPMS, and more than one system (paras. 5.1.1.1. and 5.1.1.2.)

Paragraph 5.1.1.1. now covers both the TPRS and the CTIS, and the separate CTIS paragraph 5.1.1.2. is deleted. Either is deemed equivalent for Type Approval to a TPMS when it fulfils paragraphs 5.1.2., 5.1.3. and 5.4. to 5.6. and Annex 4 test criteria. In this case, a TPMS is not required to be installed. With more than one system as defined in paragraphs 2.8., 2.14. or 2.15. installed, the system(s) which communicate(s) warning messages to the driver need approval. Before, all systems needed approval. If more than one system is installed on the vehicle, contradictory information must not be displayed to the driver, for example by prioritization.

A Tyre Pressure Refill System (TPRS) or a Central Tyre Inflation System (CTIS) shall be deemed to be equivalent for Type Approval to a Tyre Pressure Monitoring System (TPMS) when it fulfils the requirements of paragraph 5.1.2., 5.1.3. and 5.4. to 5.6. and the test criteria of Annex 4 to this Regulation are met. In this case TPMS is not required to be installed.
A Central Tyre Inflation System (CTIS) shall be deemed to be equivalent to a Tyre Pressure Monitoring System (TPMS) when the test criteria of Annex 4 to this Regulation are met. In this case TPMS is not required to be installed.
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Malfunction warning and communication interface now cover TPRS and CTIS (paras. 5.4.1. to 5.6.1.2.)

Paragraphs 5.4.1. to 5.4.3., 5.5.6., 5.6.1. and 5.6.1.1. now refer to the TPMS/ TPRS/ CTIS instead of the TPMS. Paragraph 5.5.6. now says “low tyre pressure” instead of “under-inflation”. Paragraph 5.6.1.2. applies in the case of a point-to-point link between a towing vehicle ECU and a towed vehicle ECU. In that case, the towed vehicle ECU which constitutes part of the link must now provide an interface according to an open standard specification. Before, the text said that there must be an open standard specification. The interface lets ECU(s) providing TPMS/ TPRS /CTIS functionality outside the link connect, communicate and operate through that ECU with the towing vehicle ECU.

The TPMS / TPRS/ CTIS shall illuminate the warning signal described in paragraph 5.5. not more than 10 minutes after the occurrence of a malfunction that affects the generation or transmission of control or response signals in the vehicle's tyre pressure monitoring systemTPMS/ TPRS/ CTIS.
The malfunction indication warning signal described in paragraph 5.5. shall be illuminated whenever the towed vehicle TPMS / TPRS/ CTIS provides a malfunction indication via the communication interface described in paragraph 5.6.
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Alternative procedure for a subject trailer (paras. 5.7. and 5.7.1.)

New paragraph 5.7. is headed “Alternative procedure for a subject trailer”. Paragraph 5.7.1. applies when a manufacturer chooses Annex 8 to approve an O3 or O4 vehicle type for TPMS, TPRS or CTIS. In that case, information is used from test reports issued in accordance with Annex 7, Appendix 3 and / or Appendix 4.

Alternative procedure for a subject trailer
In the case that a manufacturer chooses to approve a vehicle type of category O3 or O4 with regard to TPMS, TPRS or CTIS according to Annex 8 “Alternative procedure for type approval of subject trailer(s)” to this Regulation, then information is utilized from test reports issued in accordance with Annex 7, Appendix 3 and / or Appendix 4 to this Regulation.

Test load, road surface, rim position and measurement accuracy (Annex 3, para. 1.5.1.; Annex 4, paras. 1.2. to 1.5.)

In Annex 3, paragraph 1.5.1., where there is no possibility to set or reset the system, the vehicle must be unladen, as before. In that case, systems which automatically raise the lift axle when no load is detected need the vehicle laden enough to avoid lifting those axles. In Annex 4, paragraph 1.2. adds that the road must have a surface affording good adhesion. Paragraph 1.3.1. allows any condition of load, with the mass distribution stated by the vehicle manufacturer and within each axle's maximum permissible mass. New paragraph 1.3.3. allows the vehicle rims at any wheel position, consistent with any related instructions or limitations from the vehicle's manufacturer. Pressure measurement equipment for the Annex 4 tests must now be accurate to at least +/-3 kPa, instead of +/-10 kPa.

However, in the case where there is no possibility to set or reset the system, the vehicle shall be unladen, but for systems which will automatically raise the lift axle when no load is detected the vehicle shall be laden enough to avoid lifting of those axles. For vehicles of category M1 up to a maximum mass of 3,500 kg, M2, M3, N1, N2, and N3 there may be, in addition to the driver, a second person on the front seat (if fitted) who is responsible for noting the results of the tests.
The road shall have a surface affording good adhesion. Testing shall be performed on even ground.
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Annex 3 lamp check and Annex 4 test steps (Annex 3, para. 2.2.; Annex 4, paras. 2.1. to 2.6.2.)

In Annex 3, paragraph 2.2., the ECU controlling the tell-tale must now perform the check of lamp function, instead of the tyre pressure monitoring system. New Annex 4 paragraph 2.2. requires the vehicle to stay stationary outside with the engine off, under the listed conditions, before its tyres are inflated. The stationary time is at least one hour for M1 and N1, and at least 4 hours for M2, M3, N2, N3, O3 and O4. New paragraph 2.3. requires the TPRS / CTIS to perform a check of lamp function, except for tell-tales shown in a common space. In paragraph 2.5.1., the refilling check now uses the low tyre pressure tell-tale, instead of the optical signal for refilling as described by the manufacturer. New paragraph 2.5.2. adds a refilling check according to Figure 2, and new paragraphs 2.6. to 2.6.2. add a TPRS/ CTIS malfunction detection test.

With the vehicle stationary and the ignition locking system in the "Lock" or "Off" position, activate the ignition locking system to the "On" or "Run" position. The tyre pressure monitoring system ECU controlling the tell-tale shall perform a check of lamp function for the low tyre pressure tell-tale as specified in paragraph 5.5.2. of this Regulation. This last requirement does not apply to tell-tales shown in a common space.
If a variant of any vehicle submitted for approval is fitted with twin wheels, that variant shall be used for the test and one of the tyres on a twin wheel (the “test tyre”) must be deflated for the refilling test in paragraph 2.5.
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Data communication between towing and towed vehicles (Annexes 5 and 6)

In Annexes 5 and 6, many titles, paragraphs and table entries now say “TPMS/ TPRS/ CTIS” instead of “TPMS”. In two Annex 5 tables, the references “TD11 Byte 1” to “TD11 Byte 8” are now “SAE J1939 PGN 65254 TD Byte 1” to “SAE J1939 PGN 65254 TD Byte 8”. The two Notes now require the Time/Date message definition (PGN 65254) in SAE J1939DA 202110, instead of the TD11 message definition in ISO 11992-2:2014. Signals other than Tyre Pressure Status in messages EBS23 and RGE23 must now be transmitted as “not available” in case such data is not available. New footnotes: Gateway ECU content must be prioritized, and “002” could signify other tyre pressure conditions such as “over-pressure” which this Regulation does not cover. In Part B, paragraph 4., the towed vehicle ECU providing TPMS/ TPRS/ CTIS functionality now uses source address 207 of “Other Trailer Devices”.

TPMS / TPRS/ CTIS data communication between the towing vehicle and towed vehicle(s)
TD11 Byte 1 TD11 Byte 2 TD11 Byte 3 TD11 Byte 4 TD11 Byte 5 TD11 Byte 6 TD11 Byte 7 TD11 Byte 8 SAE J1939 PGN 65254 TD Byte 1 SAE J1939 PGN 65254 TD Byte 2 SAE J1939 PGN 65254 TD Byte 3 SAE J1939 PGN 65254 TD Byte 4 SAE J1939 PGN 65254 TD Byte 5 SAE J1939 PGN 65254 TD Byte 6 SAE J1939 PGN 65254 TD Byte 7 SAE J1939 PGN 65254 TD Byte 8
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Other wording changes (paras. 3.1., 5.1.2. and 5.1.6.; Annexes 2 and 4)

Paragraph 3.1. now writes “Tyre Pressure Monitoring System (TPMS)”, and paragraphs 5.1.2. and 5.1.6. now use abbreviations instead of the full system names. In the Annex 2 example, the approval number is now 012439 instead of 002439, and the text refers to “The first two digits”. The Annex 4 title now says “Tyre Pressure Refill Systems” instead of “Tyre Pressure Refilling Systems”.

The application for approval of a vehicle type with regard to its tyre pressure monitoring system Tyre Pressure Monitoring System (TPMS) shall be submitted by the vehicle manufacturer or by his duly accredited representative;
The effectiveness of the tyre pressure monitoring system, the tyre pressure refill system TPMS, TPRS or the central tyre inflation system CTIS fitted on a vehicle shall not be adversely affected by magnetic or electrical fields. This shall be demonstrated by fulfilling the technical requirements and respecting the transitional provisions of UN Regulation No. 10 by applying:
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Q2Why it changed

Proposed by
Task Force on Tyre Pressure Monitoring System and Tyre Installation (TF TPMSTI)
Working party
GRBP, 75th session (February 2022)

Reasons

  • The proposal aims to implement the requirements for a TPRS and a CTIS in paragraph 5 of the 01 series of amendments. All requirements for TPRS and CTIS were in Annex 4 only, and the Task Force decided to move them to paragraph 5 of the Regulation. Paragraph 5 is now valid for all three systems: TPMS, TPRS and CTIS. As a consequence, a lot of other paragraphs needed to be revised.

    Sources (3)
    “with the aim to implement the requirements for a Tyre Pressure Refill System (TPRS) and a Central Tyre Inflation System (CTIS) in paragraph 5. of the 01 series of amendments to UN Regulation No. 141”
    “All requirements to be fulfilled by TPRS and CTIS were noted in Annex 4 only. TF TPMSTI decided to move these requirements to paragraph 5. of this Regulation.”
    “Paragraph 5. “Specification and test” is now valid for all three systems: TPMS, TPRS and CTIS. As a consequence, a lot of other paragraphs needed to be revised.”

  • Annex 5, Part A, paragraph 2.1.1. and Part B, paragraph 3.1.1. were revised due to comments from the ISO Working Group ISO/TC22/SC31/WG4. The time/date data were aligned with standard SAE J1939 PGN 65254. There is a known inconsistency between standards SAE J1939 and ISO 11992-2:2014. The working group informed the Task Force that ISO would solve this issue by revising ISO 11992-2:2014 in 2022. Because SAE J1939DA 202110 was published on 21 October 2021, the Time/Date Byte 1 to Byte 8 and the Notes were revised.

    Sources (4)
    “Annex 5, Part A, paragraph 2.1.1. and Part B, paragraph 3.1.1. were revised due to the comments received by the International Organization for Standardization (ISO) Working Group ISO/TC22/SC31/WG4 after the seventy-fourth session of GRBP”
    “The time/date data were aligned with standard SAE J1939 PGN 65254.”
    “ISO/TC22/SC31/WG4 informed the Task Force that ISO would solve this issue by revising standard ISO 11992-2:2014 in 2022.”
    “Because the publication date of standard SAE J1939DA 202110 was 21 October 2021, the Time/Date Byte 1 to Byte 8 and the “Notes” in paragraph 2.1.1. of Annex 5, Part A”

  • Proposer's reason (informal document GRBP-75-33)

    Paragraph 1.5.7 requires lifted axles to be fully lowered, but on unladen trailers some lift axles may be lifted automatically. Therefore the test must be performed with sufficient load to avoid lifting those axles. The direct control of lamp function is usually not under the control of the TPMS/TPRS/CTIS. Therefore, this must be delegated to the responsible ECU of the vehicle.

    Submitted by Expert from CLEPA. Working party adoption: ECE/TRANS/WP.29/GRBP/73, para. 26.

    Sources (2)
    “In § 1.5.7 requires that lifted axles have to be fully lowered, but when unladen trailers some lift axle may be lifted automatically. Therefore the test shall be performed with sufficient load to avoid lifting those axles.”
    “The direct control of lamp function usually is not under control of the TPMS/TPRS/CTIS. Therefore this shall be delegated to the responsible ECU of the vehicle”

  • Proposer's reason (informal document GRBP-75-33)

    The former expression for “not available” signals was excluding valid information in the EBS23, like Brake-line-wear information which the Gateway ECU itself might generate. In ISO 11992-2, “Tyre pressure insufficient” includes overpressure also, while the UN Regulation No. 141 “Low Tyre Pressure Warning” indicates an underinflated tyre only. Identification data (VIN) in the TPMS/CTIS/TPRS might be hacked or corrupted, which could be crucial if it overrides the information from the Gateway ECU. Connected sub-system ECUs do not know their road train position, and each connected TPMS/TPRS/CTIS must use the fixed Source Address 207d.

    Submitted by Expert from CLEPA. Working party adoption: ECE/TRANS/WP.29/GRBP/73, para. 26.

    Sources (5)
    “is excluding valid information in the EBS23 like Brake-line-wear information which might be generated by the Gateway ECU itself.”
    “In the ECE R141 "Low Tyre Pressure Warning" is indicating an underinflated tyre only.”
    “Identification data (VIN) in the TPMS/CTIS/TPRS might be hacked or corrupted. This could be crucial if it overrides the information from the Gateway ECU”
    “Connected sub-system ECUs do not know the road train position they are and are not adapting their Source Address”
    “Each connected TPMS/TPRS/CTIS shall use the fix Source Address 207d.”

Document trail

  1. 2021-11ProposalECE/TRANS/WP.29/GRBP/2022/2Proposal by the Task Force on Tyre Pressure Monitoring System and Tyre Installation
  2. —Amended in sessionGRBP-75-10Amendments to ECE/TRANS/WP.29/GRBP/2022/2
  3. —Amended in sessionGRBP-75-33Further amendments suggested by the expert from CLEPA
  4. —Working party adoptsECE/TRANS/WP.29/GRBP/73GRBP session report, paras. 25 and 26
  5. 2022-04Sent to WP.29ECE/TRANS/WP.29/2022/87Text that GRBP sent to WP.29 and AC.1
  6. 2022-06WP.29 adoptsECE/TRANS/WP.29/1166Adopted at the 187th session (session report, para. 182)
  7. 2023-01-04In forceC.N.499.2022.TREATIES-XI.B.16.141UN depositary notification

Q3Who is affected

Vehicle manufacturer

  • To use TPRS or CTIS as TPMS equivalent, meet paragraphs 5.1.2., 5.1.3., 5.4. to 5.6. and Annex 4 (para. 5.1.1.1.).
  • If more than one system is installed, make sure that no contradictory information is displayed to the driver (para. 5.1.1.2.).

Component supplier

  • For a point-to-point link, design the towed vehicle ECU in the link to provide an open standard interface (para. 5.6.1.2.).
  • Transmit EBS23 and RGE23 signals other than Tyre Pressure Status as “not available” when such data is not available (Annex 5).
  • Use the Time/Date message definition (PGN 65254) of SAE J1939DA 202110 (Annex 5, Notes).
  • In the ECU providing TPMS/ TPRS/ CTIS functionality, use source address 207 of “Other Trailer Devices” (Annex 5, Part B, para. 4.).

Technical service / Approval authority

  • Without set or reset, test vehicles with automatic lift axles laden enough to avoid lifting those axles (Annex 3).
  • Use pressure measurement equipment accurate to at least +/-3 kPa for the TPRS and CTIS tests (Annex 4).
  • Apply the new Annex 4 paragraphs on twin wheels, stationary time, lamp check and malfunction detection (paras. 2.1. to 2.6.2.).
  • Run the new Annex 4 refilling check according to Figure 2 (para. 2.5.2.).
  • In the Annex 4 refilling check of paragraph 2.5.1., check the low tyre pressure tell-tale described in paragraph 5.5.

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ⓘ This report gives advice only. It is not legal or type-approval advice.

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