Only the original UN/ECE texts have legal effect under international public law. The status and date of entry into force of this Regulation should be checked in the latest version of the UN/ECE status document TRANS/WP.29/343, available at: http://www.unece.org/trans/main/wp29/wp29wgs/wp29gen/wp29fdocstts.html

UN Regulation No 141 – Uniform provisions concerning the approval of vehicles with regard to their Tyre Pressure Monitoring Systems (TPMS) (2021/1463)

Incorporating all valid text up to:

01 series of amendments – Date of entry into force: 30 September 2021

This document is meant purely as documentation tool. The authentic and legally binding text is ECE/TRANS/WP.29/2021/10/Rev.1.

CONTENTS

Regulation

1. Scope

2. Definitions

3. Application for approval

4. Approval

5. Specifications and tests

6. Supplementary information

7. Modifications and extension of approval of the vehicle type

8. Conformity of production

9. Penalties for non-conformity of production

10. Production definitively discontinued

11. Names and addresses of Technical Services responsible for conducting approval tests, and of Type Approval Authorities

12. Transitional provisions

Annexes

1 Communication

2 Arrangements of approval marks

3 Test requirements for Tyre Pressure Monitoring Systems (TPMS)

4 Test requirements for Tyre Pressure Refilling Systems (TPRS) and Central Tyre Inflation systems (CTIS)

5 Compatibility between towing vehicles and towed vehicles with respect to ISO 11992 data communication

6 Test procedure to assess the functional compatibility of vehicles equipped with ISO 11992 communication interfaces

1. Scope

This Regulation applies to the approval of vehicles of category: M1 up to a maximum mass of 3 500 kg, M2, M3, N1, N2, N3, O3 and O4, (1) when equipped with a tyre pressure monitoring system.

2. Definitions

For the purposes of this Regulation:

2.1. ‘Approval of a vehicle’ means the approval of a vehicle type with regard to its tyre pressure monitoring system.

2.2. ‘Vehicle type’ means vehicles which do not differ significantly in such essential aspects as: (a) The manufacturer’s trade name or mark; (b) Vehicle features which significantly influence the performances of the tyre pressure monitoring system; (c) The design of the tyre pressure monitoring system.

2.3. ‘Wheel’ means a complete wheel consisting of a rim and a wheel disc;

2.4 ‘Twin wheel’ means the fitment of a pair of wheels on one side of an axle, on the same hub;

2.5. ‘Tyre’ means a pneumatic tyre, being a reinforced flexible envelope that is provided with, or forms in conjunction with the wheel on which it is mounted, a continuous, essentially toroidal, closed chamber containing a gas (usually air) or a gas and liquid, that is intended normally to be used at a pressure greater than atmospheric pressure; Tyres shall be classified as follows: (a) Class C1 tyres –Tyres conforming to UN Regulation No 30; (b) Class C2 tyres –Tyres conforming to UN Regulation No 54 and identified by a load capacity index in single formation lower or equal to 121 and a speed category symbol higher or equal to ‘N’; (c) Class C3 tyres: Tyres conforming to UN Regulation No 54 and identified by: (i) A load capacity index in single formation higher or equal to 122; or (ii) A load capacity index in single formation lower or equal to 121 and a speed category symbol lower or equal to ‘M’.

2.6. ‘Maximum mass’ means the maximum value of the vehicle stated by the manufacturer to be technically permissible (this mass may be higher than the ‘permissible maximum mass’ laid down by the national administration);

2.7. ‘Maximum axle load’ means the maximum value, as indicated by the manufacturer, of the total vertical force between the contact surfaces of the tyres or tracks of one axle and the ground and resulting from the part of the vehicle mass supported by that axle; this load may be higher than the ‘authorized axle load’ laid down by the national administration. The sum of the axle loads may be greater than the value corresponding to the total mass of the vehicle;

2.8. ‘Tyre Pressure Monitoring System (TPMS)’ means a system fitted on a vehicle which can evaluate the pressure of the tyres or the variation of pressure over time and transmit corresponding information to the user while the vehicle is running;

2.9. ‘Cold tyre inflation pressure’ means the tyre pressure at ambient temperature, in the absence of any pressure build-up due to tyre usage;

2.10. ‘Recommended cold inflation pressure (P rec )’ means the pressure recommended for each tyre position by the vehicle manufacturer, for the intended service conditions (e.g. speed and load) of the given vehicle, as defined on the vehicle placard and/or the vehicle owner’s manual;

2.11. ‘In service operating pressure (P warm )’ means the inflation pressure for each tyre position elevated from the cold pressure (P rec ) by temperature effects during vehicle usage;

2.12. ‘Test Pressure (P test )’ means the actual pressure of the tyre(s) selected for each tyre position after deflation during the test procedure.

2.13. ‘Cumulative driving time’ means the total time elapsed where the vehicle of category M1 up to a maximum mass of 3 500 kg or N1 is driven at speeds equal to or higher than 40 km/h and further deducted by 120 seconds for each event where the vehicle speed drops below 40 km/h or where the vehicle of other categories than M1 up to a maximum mass of 3 500 kg and N1 is driven at speeds equal to or higher than 30 km/h and further deducted by 120 seconds for each event where the vehicle speed drops below 30 km/h.

2.14. ‘Tyre Pressure Refill System (TPRS)’ means a system fitted on a vehicle which refills underinflated tyres fitted to an axle of the vehicle with air pressure from a vehicle mounted reservoir (infrastructure) while the vehicle is running but not limited to.

2.15. ‘Central Tyre Inflation System (CTIS)’ means a system fitted on a vehicle which controls the air pressure in each tyre fitted to an axle of the vehicle with air pressure from a vehicle mounted reservoir (infrastructure) while the vehicle is running but not limited to.

3. Application for approval

3.1. The application for approval of a vehicle type with regard to its tyre pressure monitoring system shall be submitted by the vehicle manufacturer or by his duly accredited representative;

3.2. It shall be accompanied, in triplicate, by a description of the vehicle type with regard to the items specified in Annex 1 to this Regulation:

3.3. A vehicle representative of the vehicle type to be approved shall be submitted to the Type Approval Authority or the Technical Service responsible for conducting the approval tests.

3.4. The Type Approval Authority shall verify the existence of satisfactory arrangements for ensuring effective control of the conformity of production before type approval is granted.

4. Approval

4.1. If the vehicle submitted for approval pursuant to this Regulation meets all the requirements of paragraph 5 below, approval of that vehicle type shall be granted.

4.2. An approval number shall be assigned to each type approved. Its first two digits (at present 01 for the Regulation as amended by the 01 series of amendments) shall indicate the series of amendments incorporating the most recent major technical amendments made to the regulation at the time of issue of the approval. The same Contracting Party may not assign the same number to another type of vehicle.

4.3. Notice of approval or of extension or of refusal of approval of a vehicle type pursuant to this Regulation shall be communicated to the Contracting Parties to the Agreement which apply this Regulation by means of a form conforming to the model in Annex 1 to this Regulation.

4.4. There shall be affixed, conspicuously and in a readily accessible place specified on the approval form, to every vehicle conforming to a vehicle type approved under this Regulation an international approval mark consisting of:

4.4.1. A circle surrounding the letter ‘E’ followed by the distinguishing number of the country which granted approval; ( 2 )

4.4.2. The number of this Regulation, followed by the letter ‘R’, a dash and the approval number to the right of the markings prescribed in paragraph 4.4.1.

4.5. If the vehicle conforms to a vehicle type approved, under one or more regulations annexed to the Agreement, in the country which granted approval under this Regulation, the symbol prescribed in paragraph 4.4.1. need not be repeated; in such a case, the regulation and approval numbers and the additional symbols for all the regulations under which approval has been granted in the country which granted approval under this Regulation shall be placed in vertical columns to the right of the symbol prescribed in paragraph 4.4.1.

4.6. The approval mark shall be clearly legible and be indelible.

4.7. The approval mark shall be placed close to or on the vehicle data plate affixed by the manufacturer.

4.8. Annex 2 to this Regulation gives examples of approval marks.

5. Specifications and tests

5.1. General

5.1.1. Any vehicle of categories M 1 up to a maximum mass of 3 500 kg, M 2 , M 3 , N 1 , N 2 , N 3 , O 3 and O 4 , in all cases fitted with a Tyre Pressure Monitoring System (TPMS) complying with the definition of paragraph 2.8, shall meet the performance requirements contained in paragraphs 5.1.2 to 5.6 of this Regulation over a wide range of road and environmental conditions encountered within the territory of the Contracting Parties.

5.1.1.1. A Tyre Pressure Refill System (TPRS) 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.

5.1.1.2. 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.

5.1.1.3. If more than one system as defined in paragraphs 2.8, 2.14 or 2.15 has been installed, all systems shall be approved according to the requirements of this Regulation.

5.1.2. The effectiveness of the tyre pressure monitoring system, the tyre pressure refill system or the central tyre inflation system 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: (a) The 03 series of amendments for vehicles without a coupling system for charging the Rechargeable Electric Energy Storage System (traction batteries); (b) The 06 series of amendments for vehicles with a coupling system for charging the Rechargeable Electric Energy Storage System (traction batteries).

5.1.3. For vehicles of category M 1 up to a maximum mass of 3 500 kg and N 1 , the system shall operate from a speed of 40 km/h or below, up to the vehicle’s maximum design speed. For vehicles of categories M2, M3, N2, N3, O3 and O4, the system shall operate from a speed of 30 km/h or below, up to the vehicle’s maximum design speed.

5.1.4. The vehicle shall fulfil the tests (puncture, diffusion and malfunction) as specified in Annex 3 to this Regulation.

5.1.5. If a variant of any vehicle submitted for approval is fitted with twin wheels, that variant shall be used for the tests defined in Annex 3 to this Regulation and one of the tyres on a twin wheel (the ‘test tyre’) must be deflated for the puncture test in 2.5 of Annex 3 to this Regulation.

5.1.6. For vehicles of categories M 1 up to a maximum mass of 3 500 kg and N 1 In case of a given warning and if the tyre pressure monitoring system is equipped with a reset function but does not detect a minimum pressure as defined in paragraphs 5.2 and 5.3 after executing the reset function, the reset control shall be designed and/or located inside the vehicle in such a way that the risk of an inadvertent reset by vehicle occupants or cargo is reduced. For vehicles where the tyre pressure monitoring system does not detect if the pressure is above a minimum pressure as defined in paragraphs 5.2 and 5.3 after executing the reset function, the tyre pressure monitoring system shall include at least measures avoiding a reset if the vehicle did not become stationary after a pressure warning was issued, and either (a) Measures avoiding inadvertent reset control operation (e.g. shortly touching on the reset control or continuous blocking of the reset control by vehicle occupants or cargo), or (b) An activation by at least two deliberate actions (e.g. in a menu based system). The manufacturer shall provide in the vehicle owner’s handbook, or by any other communication means in the vehicle, the necessary information.

5.2. Tyre pressure detection for incident-related pressure loss.

5.2.1. For vehicles of category M 1 up to a maximum mass of 3 500 kg and N 1 , fitted with tyres of the tyre class C1, the TPMS shall illuminate the warning signal described in paragraph 5.5 within not more than 10 minutes of cumulative driving time after the in service operating pressure in one of the vehicle’s tyres has been reduced by twenty per cent or it is at a minimum pressure of 150 kPa, whichever is higher.

5.2.2. For vehicles of category M 1 up to a maximum mass of 3 500 kg and N 1 , fitted with tyres of the tyre class C2, the TPMS shall illuminate the warning signal described in paragraph 5.5 within 10 minutes of cumulative driving time after the in service operating pressure in one of the vehicle’s tyres has been reduced by 20 per cent or it is at a minimum pressure of 220 kPa, whichever is higher.

5.2.3. For vehicles of category M 2 , M 3 , N 2 and N 3 , fitted with tyres of the tyre class C2 or C3, the TPMS shall illuminate the warning signal described in paragraph 5.5 within not more than 10 minutes of cumulative driving time after the in-service operating pressure in one of the vehicle’s rolling tyres in contact with the ground has been reduced by 20 per cent.

5.2.4. For vehicles of category O 3 and O 4 , fitted with tyres of the tyre class C2 or C3, the TPMS shall illuminate the warning signal described in paragraph 5.5 within not more than 10 minutes of cumulative driving time after the in service operating pressure in one of the vehicle’s rolling tyres in contact with the ground has been reduced by 20 per cent.

5.2.5. The low tyre pressure warning signal described in paragraph 5.5 shall be illuminated whenever the towed vehicle TPMS provides low tyre pressure warning information via the communication interface described in paragraph 5.6.

5.3. Detection for a tyre pressure level significantly below the recommended pressure for optimum performance including fuel consumption and safety.

5.3.1. For vehicles of category M 1 up to a maximum mass of 3 500 kg and N 1 , fitted with tyres of the tyre class C1, the TPMS shall illuminate the warning signal described in paragraph 5.5. within not more than 60 minutes of cumulative driving time after the in service operating pressure in any of the vehicle’s tyres, has been reduced by twenty per cent or it is at a minimum pressure of 150 kPa, whichever is higher.

5.3.2. For vehicles of category M 1 up to a maximum mass of 3 500 kg and N 1 , fitted with tyres of the tyre class C2, the TPMS shall illuminate the warning signal described in 5.5 within not more than 60 minutes of cumulative driving time after the in-service operating pressure in any of the vehicle’s tyres has been reduced by 20 per cent or it is at a minimum pressure of 220 kPa, whichever is higher.

5.3.3. For vehicles of category M 2 , M 3 , N 2 and N 3 , fitted with tyres of the tyre class C2 or C3, the TPMS shall illuminate the warning signal within not more than 60 minutes of cumulative driving time after the in-service operating pressure in any of the vehicle’s rolling tyres in contact with the ground has been reduced by 20 per cent.

5.3.4. For vehicles of category O 3 and O 4 , fitted with tyres of the tyre class C2 or C3, the TPMS shall transmit an appropriate warning signal described in 5.5 within not more than 60 minutes of cumulative driving time after the in-service operating pressure in any of the vehicle’s rolling tyres in contact with the ground has been reduced by 20 per cent.

5.3.5. The low tyre pressure warning signal described in paragraph 5.5 shall be illuminated whenever the towed vehicle TPMS provides low tyre pressure warning information via the communication interface described in paragraph 5.6.

5.4. Malfunction detection.

5.4.1. The TPMS 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 system.

5.4.2. The malfunction indication warning signal described in paragraph 5.5 shall be illuminated whenever the towed vehicle TPMS provides a malfunction indication via the communication interface described in paragraph 5.6.

5.4.3. The malfunction indication warning signal described in paragraph 5.5 shall be illuminated whenever no valid TPMS information is available from a connected towed vehicle, that is required to have TPMS, via any communication interface described in paragraph 5.6.

5.5. Warning indication.

5.5.1. The warning indication shall be by means of an optical warning signal conforming to UN Regulation No 121.

5.5.2 In the case of a vehicle of category N 2 or N 3 towing at least one vehicle of category O 3 or O 4 , the optical warning signal referred to in paragraph 5.5.1 must indicate whether any warning relates to the individual towing or to the towed vehicle(s).

5.5.3. The warning signal shall be activated when the ignition (start) switch is in the ‘on’ (run) position (bulb check). This requirement does not apply to tell-tales shown in a common space.

5.5.4. The warning signal must be visible even by daylight; the satisfactory condition of the signal must be easily verifiable by the driver from the driver’s seat.

5.5.5 For vehicles of category O 3 and O 4 , the optical warning signal referred to in paragraph 5.5.1 must be displayed to the driver of the towing vehicle of category N 2 or N 3 , as specified in paragraph 5.5.4.

5.5.6. The malfunction indication may be the same warning signal as the one used to indicate under-inflation. If the warning signal described in paragraph 5.5.1 is used to indicate both under-inflation and a malfunction of the TPMS, the following shall apply: with the ignition (start) switch in the ‘on’ (run) position the warning signal shall flash to indicate a malfunction. After a short period of time the warning signal shall remain continuously illuminated as long as the malfunction exists and the ignition (start) switch is in the ‘on’ (run) position. The flashing and illumination sequence shall be repeated each time the ignition (start) switch is in the ‘on’ (run) position until the malfunction has been corrected.

5.5.7. The tell-tale of the warning described in paragraph 5.5.1 may be used in a flashing mode in order to provide information about the reset status of the tyre pressure monitoring system in accordance with the owner’s manual of the vehicle.

5.6. Communications interface between towing and towed vehicles

5.6.1 Vehicles of category N 2 or N 3 towing at least one vehicle of category O 3 or O 4 and vehicles of category O 3 and O 4 shall be equipped with a communication interface to exchange TPMS data information between towing and towed vehicles. This may be achieved as a wired or a wireless interface, provided that the TPMS equipment in the towing vehicle and in the towed vehicle(s) are compatible.

5.6.1.1. The data communication with wired equipment shall be based on the braking electric control line conforming to ISO 11992-1:2019 and ISO 11992-2:2014 and be a point-to-point type using the seven pin connector according to ISO 7638-1:2018 or ISO 7638-2:2018 or an appropriate automated connector. Other wired specifications may be used, provided that the TPMS equipment in the towing vehicle and in the towed vehicle(s) are compatible and fulfil the same functional requirements.

5.6.1.1.1. The support of messages is specified within Part A of Annex 5 to this Regulation for the towing vehicle and the towed vehicle(s).

5.6.1.1.2. The functional compatibility of towing and towed vehicles equipped with data communication lines as described in paragraph 5.6.1.1. above shall be assessed at the time of type approval by checking that the relevant provisions as specified in Part A of Annex 5 are fulfilled. Annex 6 to this Regulation provides a procedure for tests that may be used to perform this assessment.

5.6.1.2. In the case of a point-to-point link between a towing vehicle ECU and a towed vehicle ECU, there shall be an open standard specification to allow an ECU providing TPMS functionality, which does not constitute part of the point-to-point link, to connect, communicate and operate via the towed vehicle ECU which constitutes part of the point-to-point link, i.e. standardised gatewaying. This data communication interface is specified in Part B of Annex 5.

5.6.1.3. In the case of data communication with wireless equipment, the communication link shall be an open standard specification. Provision shall be made to ensure that the wireless link is set up between the physically connected vehicles (as opposed to other vehicles in the vicinity), and that information shared over this link is secure against outside interference. The same functional requirements as required in paragraph 5.6.1.1 shall be fulfilled.

6. Supplementary information

6.1. The owner’s manual, if any, of the vehicle shall contain at least the following information:

6.1.1. A statement that the vehicle is equipped with such a system (and information how to reset the system, if the actual system includes such a feature).

6.1.2. An image of the tell-tale symbol described in paragraph 5.5.1 (and an image of the malfunction tell-tale symbol, if a dedicated tell-tale is used for this function).

6.1.3. Additional information about the significance of the low tyre pressure warning tell-tale illuminating and a description of the corrective action to be undertaken if this happens, including the reset procedure if the actual system includes such a feature.

6.2. If no owner’s manual is supplied with the vehicle, the information required in paragraph 6.1 above shall be displayed in a prominent place on the vehicle.

7. Modifications and extension of approval of the vehicle type

7.1. Every modification of the vehicle type as defined in paragraph 2.2 of this Regulation shall be notified to the Type Approval Authority which approved the vehicle type. The Type Approval Authority may then either:

7.1.1. Consider that the modifications made do not have an adverse effect on the conditions of the granting of the approval and grant an extension of approval;

7.1.2. Consider that the modifications made affect the conditions of the granting of the approval and require further tests or additional checks before granting an extension of approval.

7.2. Confirmation or refusal of approval, specifying the alterations, shall be communicated by the procedure specified in paragraph 4.3 above to the Contracting Parties to the Agreement applying this Regulation.

7.3. The Type Approval Authority shall inform the other Contracting Parties of the extension by means of the communication form which appears in Annex 1 to this Regulation. It shall assign a serial number to each extension, to be known as the extension number.

8. Conformity of production

8.1. The conformity of production procedures shall comply with those set out in Schedule 1 to the Agreement (E/ECE/TRANS/505/Rev.3), with the following requirements:

8.2. The Type Approval Authority which has granted type approval, may at any time verify the conformity of production in each production facility. The normal frequency of these verifications shall be at least once per year.

9. Penalties for non-conformity of production

9.1. The approval granted in respect of a vehicle type pursuant to this Regulation may be withdrawn if the requirements laid down in paragraph 8 are not complied with.

9.2. If a Contracting Party to the Agreement, which applies this Regulation, withdraws an approval it has previously granted, it shall forthwith so notify the other Contracting Parties applying this Regulation, by means of a copy of the approval form bearing at the end, in large letters, the signed and dated annotation ‘APPROVAL WITHDRAWN’.

10. Production definitively discontinued

If the holder of the approval completely ceases to manufacture a type of vehicle approved in accordance with this Regulation, he shall so inform the authority which granted the approval. Upon receiving the relevant communication that authority shall inform thereof the other Contracting Parties to the Agreement applying this Regulation by means of a copy of the approval form bearing at the end, in large letters, the signed and dated annotation ‘PRODUCTION DISCONTINUED’.

11. Names and addresses of Technical Services responsible for conducting approval tests, and of Type Approval Authorities

The Contracting Parties to the Agreement which apply this Regulation shall communicate to the United Nations Secretariat the names and addresses of the Technical Services responsible for conducting approval tests and of the Type Approval Authorities which grant approval and to which forms certifying approval or extension or refusal or withdrawal of approval, issued in other countries, are to be sent.

12. Transitional provisions

12.1. As from the official date of entry into force of the 01 series of amendments, no Contracting Party applying this Regulation shall refuse to grant or refuse to accept type approvals under this Regulation as amended by the 01 series of amendments.

12.2. As from 6 July 2022, for vehicle types of category M 1 and as from 6 July 2024 for vehicle types of other categories than M 1 , Contracting Parties applying this Regulation shall not be obliged to accept type approvals to the preceding series of amendments, first issued after 6 July 2022.

12.3. Until 6 July 2022, for vehicle types of category M 1 and until 6 July 2024 for vehicle types of other categories than M 1 , Contracting Parties applying this Regulation shall accept type approvals to the preceding series of amendments, first issued before 6 July 2022.

12.4. As from 6 July 2022, for vehicle types of category M 1 and as from 6 July 2024 for vehicle types of other categories than M 1 , Contracting Parties applying this Regulation shall not be obliged to accept type approvals issued to the preceding series of amendments to this Regulation.

12.5. Notwithstanding the transitional provisions above, Contracting Parties who start to apply this Regulation after the date of entry into force of the most recent series of amendments are not obliged to accept type approvals which were granted in accordance with any of the preceding series of amendments to this Regulation/are only obliged to accept type approval granted in accordance with the 01 series of amendments.

12.6. Notwithstanding paragraph 12.4., Contracting Parties applying this Regulation shall continue to accept type approvals issued according to the preceding series of amendments to this Regulation, for the vehicles/vehicle systems which are not affected by the changes introduced by the 01 series of amendments.

12.7. Contracting Parties applying this Regulation may grant type approvals according to any preceding series of amendments to this Regulation. ( 3 )

12.8. Contracting Parties applying this Regulation shall continue to grant extensions of existing approvals to any preceding series of amendments to this Regulation. 3

(1) As defined in the Consolidated Resolution on the Construction of Vehicles (R.E.3.), document ECE/TRANS/WP.29/78/Rev.6, para. 2 – www.unece.org/trans/main/wp29/wp29wgs/wp29gen/wp29resolutions.html

(2) The distinguishing numbers of the Contracting Parties to the 1958 Agreement are reproduced in Annex 3 to the Consolidated Resolution on the Construction of Vehicles (R.E.3), document ECE/TRANS/WP.29/78/Rev.6, Annex 3 – www.unece.org/trans/main/wp29/wp29wgs/wp29gen/wp29resolutions.html

(3) Note by the secretariat: the wording was adjusted in line with the decision of WP.29 at its November 2020 session (ECE/TRANS/WP.29/1155, paras. 92 and 93, and informal document WP.29-182-11).