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UN-R51-04

Main body, Paragraph 1. amended as following:

1. Scope

This Regulation contains provisions on the sound emitted by motor vehicles and applies to vehicles of categories M and N. [1]

The specifications in this Regulation are intended to reproduce the sound levels which are generated by vehicles during normal driving in urban traffic.

This regulation provides, as well, [Real Driving additional sound emission provisions (RD-ASEP)] for vehicles of categories M1 and N1 referring to a very wide range of on road driving conditions including high accelerations and engine speeds with extreme accelerations in an extended speed range representative for urban and suburban traffic , except highways .

Man body, introduction of new definitions in paragraph 2

2. Definitions

2.29 " Exhaust silencing system with variable geometry " means a silencing system, not including pressure charging, containing one or more active, passive, or self-actuated moving parts or devices.

These parts or devices will cause a change of the gas flow through the exhaust silencing system and result in a change of the sound reduction performance, by opening or closing one or more valves in the exhaust gas flow as a function of varying driving or engine conditions (rpm, load, speed, etc.).

Active devices mean actuators, controlled by any means.

Passive or self-actuated devices mean units controlled e.g. by exhaust flow.

 

2.30 Sound enhancement system ” means a system that is installed to a vehicle for producing exterior sound, such as but not limited to sound actuators.

It is irrelevant whether the system is integrated into an exhaust silencing system or mounted as an individual unit.


Main body, Paragraph 6.2.3. amended as following:

6.2.3. [Real Driving Additional sound emission provisions ]

The [Real Driving Additional Sound Emission Provisions ( RD- ASEP) ] apply only to vehicles of categories M 1 and N 1 equipped with :

-           an internal combustion engine for propulsion of the vehicle, or

-           any other propulsion technology fitted with a sound enhancement system.

6.2.3.1. Application

Notwithstanding the requirements above, vehicles equipped with an ICE for propulsion are exempted from RD-ASEP, if:

-           their exhaust silencing systems have no variable geometries and the vehicle has no sound enhancement systems, or;

-           they are only equipped with sound enhancement systems fully in compliance with other UN Regulations.

Notwithstanding the requirements above, vehicles equipped with propulsion system other than ICE are exempted from RD-ASEP, if they are only equipped with sound enhancement systems fully in compliance with other UN Regulations, e.g. with the UN Regulation 138.

Vehicles are deemed to fulfil the requirements of Annex 7, if the vehicle manufacturer provides technical documents to the type approval authority showing, that the difference between maximum and minimum engine speed of the vehicles at BB' for any test condition inside the ASEP control range defined in paragraph 3.3. of Annex 7 to this Regulation (including Annex 3 conditions) does not exceed 0.15 x S. This article is intended especially for non-lockable transmissions with variable gear ratios (CVT).

Vehicles are exempted from ASEP if one of the following conditions is fulfilled:

(a) For vehicles of category N1, if the engine capacity does not exceed 660 cc and the power-to-mass ratio PMR calculated by using the technically permissible maximum laden mass does not exceed 35.

(b) For vehicles of category N1, if the payload is at least 850 kg and the power-to-mass ratio calculated by using the technically permissible maximum laden mass does not exceed 40.

(c) For vehicles of category N1 or M1 derived from N1 if the technically permissible maximum laden mass is greater than 2.5 tons and the R-point height is greater than 850 mm from the ground and the power- to-mass ratio calculated by using the technically permissible maximum laden mass does not exceed 40.

[Regardless of the exemption specified above, the sound emissions of the vehicle under typical on-road driving conditions, which are not covered by this regulation, shall not deviate from the evaluation principles outlined by Annex 7 in a significant manner.]

The sound emission of the vehicle under typical on-road driving conditions, which are different from those under which the type-approval test set out in Annex 3 and Annex 7 was carried out, shall not deviate from the test result in a significant manner.

Any electric sound enhancement system for the purpose of the exterior sound emission shall be operational during the type-approval test.

6.2.3.2. Specifications

The vehicle shall meet the requirements of Annex 7 to this Regulation. If the vehicle has different modes which affect sound emission, all modes shall comply with the requirements in Annex 7.

6.2.3.3. Provisions against misuse of test detection

6.2.3.1. The vehicle manufacturer shall not intentionally alter, adjust, or introduce any mechanical, electrical, thermal, or other device or procedure solely for the purpose of fulfilling the sound emission requirements as specified under this Regulation which is not operational during typical on-road operation.

6.2.3.2.      The vehicle shall meet the requirements of Annex 7 to this Regulation.

6.2.3.3.      In applying for type approval, the manufacturer shall provide a statement, in conformity with the Appendix 1 of Annex 7, that the vehicle type to be approved complies with the requirements of paragraph 6.2.3. of this Regulation.

 

Introduction of a new paragraph 6.2.4.

 

6.2.4. Provisions against manipulation

 

6.2.4.1. Software manipulation
 

6.2.4.1.1. Any electronically controlled sound emission system shall be supervised for proper functioning. A defect, malfunction or manipulation shall be recognized by the system and an information be displayed to the driver.

 

6.2.4.1.2. Any component of the vehicle which is relevant for the exterior sound emission and is controlled by an electronic control computer unit shall include features to deter modification, except as authorised by the manufacturer.

 

Any reprogrammable computer codes or operating parameters shall be resistant to tampering and afford a level of protection at least as good as the provisions in ISO 15031-7 (March 15, 2001) . Any removable calibration memory chips shall be potted encased in a sealed container or protected by electronic algorithms and shall not be changeable without the use of specialized tools and procedures.

 

6.2.4.1.3. Computer-coded engine operating parameters shall not be changeable without the use of specialized tools and procedures (e.g. soldered or potted computer components or sealed (or soldered) enclosures).

 

6.2.4.1.4. Manufacturers using programmable computer code systems shall deter unauthorised reprogramming. Manufacturers shall include enhanced tamper protection strategies and write-protect features requiring electronic access to an off-site computer maintained by the manufacturer.              
 

6.2.4.1.5. The Type Approval Authority may exempt a vehicle manufacturer from above requirements either in parts or completely for those vehicles which are unlikely to require protection. The rational for the exemption shall be documented.

 


6.2.4.2. Hardware manipulation

 

Any hardware component relevant for the control of a sound emission system, shall be mounted to the vehicle in a way, that removal or replacement is only possible by special tools and expertise. This applies in general to control units for active systems and to components like exhaust or intake flaps, or to vacuum tubes controlling the flaps, baffles, exit-cones and other parts whose primary function is as part of the silencing/expansion chambers.

 

The removal or rendering inoperative by any person, other than for purposes of maintenance, repair, or replacement, of any device or element of design incorporated into any new vehicle for the purpose of sound reduction control prior to its sale or delivery to the ultimate purchaser or while it is in use.

Design elements that enable removal or rendering inoperative of any sound reduction control elements are prohibited.

 


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