Appendix 3b Methodology for the assessment of AESF1

The assessment of the AES by the type-approval authority shall include at least the following verifications:

1. (1)

   The increase of emissions induced by the AES shall be kept at the lowest possible level:

   1. (a)

      The increase of total emissions when using an AES shall be kept at the lowest possible level throughout the normal use and life of the vehicles;

   2. (b)

      Whenever a technology or design that would allow for improved emission control is available on the market at the time of the AES preliminary assessment it shall be used with no unjustified modulation

2. (2)

   When used to justify an AES, the risk of sudden and irreparable damage to the ‘propulsion energy converter and the drivetrain’, as defined in Mutual Resolution No. 2 (M.R.2) of the 1958 and 1998 Agreements of UNECE containing Vehicle Propulsion System DefinitionsM1, shall be appropriately demonstrated and documented, including the following information:

   1. (a)

      Proof of catastrophic (i.e. sudden and irreparable) engine damage shall be provided by the manufacturer, along with a risk assessment which includes an evaluation of the likelihood of the risk occurring and severity of the possible consequences, including results of tests carried out to this effect;

   2. (b)

      When a technology or design is available on the market at the time of the AES application that eliminates or reduces that risk, it shall be used to the largest extent technically possible (i.e. with no unjustified modulation);

   3. (c)

      Durability and the long-term protection of the engine or components of the emission control system from wear and malfunctioning shall not be considered an acceptable reason to grant an exemption from the defeat device prohibition.

3. (3)

   An adequate technical description shall document why it is necessary to use an AES for the safe operation of the vehicle:

   1. (a)

      Proof of an increased risk to the safe operation of the vehicle should be provided by the manufacturer along with a risk assessment which includes an evaluation of the likelihood of the risk occurring and severity of the possible consequences, including results of tests carried out to this effect;

   2. (b)

      When a different technology or design is available on the market at the time of the AES application that would allow for lowering the safety risk, it shall be used to the largest extent technically possible (i.e. with no unjustified modulation).

4. (4)

   An adequate technical description shall document why it is necessary to use an AES during engine start:

   1. (a)

      Proof of the need to use an AES during engine start shall be provided by the manufacturer along with a risk assessment which includes an evaluation of the likelihood of the risk occurring and severity of the possible consequences, including results of tests carried out to this effect;

   2. (b)

      Where a different technology or design is available on the market at the time of the AES application that would allow for improved emission control upon engine start, it shall be used to the largest extent technically possible.