Document ID: chunk:federal_register_of_legislation:F2023L00129:reg:99:p23
Version: federal_register_of_legislation:F2023L00129
Segment Type: reg
Provision Reference: reg 99 (pt 23/39)
Character Range: 1217581–1220561

of NOx control measures
              8.1.  Annex 11 (on correct operation of NOx control measures) shall apply to HDDF engines and vehicles, whether operating in dual-fuel or diesel mode.

8.2. Additional general OBD requirements in case of Type 1B, Type 2B and Type 3B dual-fuel engines and vehicles
              8.2.1. In case of HDDF Type 1B, Type 2B and Type 3B, the torque considered to apply low level inducement defined in Annex 11 shall be the lowest of the torques obtained in diesel mode and in dual-fuel mode.

              8.2.2.  The requirements of section 7.1.1. concerning additional general OBD requirements in case of Type 1B, Type 2B and Type 3B dual-fuel engines and vehicles shall also apply to the diagnostic system related to the correct operation of NOx control systems.

           In particular:

              8.2.2.1. A possible influence of the mode of operation on the malfunction detection shall not be used to extend the time until an operability restriction becomes active.

              8.2.2.2. A change of the mode of operation (dual-fuel to diesel or vice-versa) shall not stop nor reset the mechanisms implemented to comply with the specification of Annex 11 (counters, etc.). However, in the case where one of these mechanisms (for example a diagnostic system) depends on the actual operation mode the counter associated with that mechanism may, at the request of the manufacturer and upon approval of the Type Approval Authority:

                  (a) Halt and, when applicable, hold their present value when the operation mode changes;

                  (b) Restart and, when applicable, continue counting from the point at which they have been held when the operation mode changes backs to the other operation mode.

              9. Conformity of in-service engines or vehicles/engines

              The conformity of in-service dual-fuel engines and vehicles shall be performed according to the requirements specified in Annex 8.

           The PEMS tests shall be performed in dual-fuel mode.

              9.1. In the case of Type 1B, Type 2B and Type 3B dual-fuel engines, an additional PEMS test shall be performed in Diesel mode on the same engine and vehicle immediately after, or before, a PEMS test is performed in dual-fuel mode.

              In that case the pass or fail decision of the lot considered in the statistical procedure specified in Annex 8 shall be based on the following:

                  (a) A pass decision is reached for an individual vehicle if both the PEMS test in dual-fuel mode and the PEMS test in Diesel mode have concluded a pass;

                  (b) A fail decision is reached for an individual vehicle if either the PEMS test in dual-fuel mode or the PEMS test in Diesel mode has concluded a fail.

              10. Additional test procedures

10.1. Additional emission test procedure requirements for dual-fuel engines
              10.1.1.  Dual-fuel engines shall comply with the