Document ID: chunk:federal_register_of_legislation:F2023L00129:reg:99:p21
Version: federal_register_of_legislation:F2023L00129
Segment Type: reg
Provision Reference: reg 99 (pt 21/39)
Character Range: 1211923–1214937

span of all members of the dual-fuel engine family remains within the percentage specified in paragraph 3.1.1. (for example, through algorithms, functional analyses, calculations, simulations, results of previous tests, etc.).

              6.4. Additional demonstration requirements in case of a universal fuel range type-approval

              On request of the manufacturer and with approval of the Type Approval Authority, a maximum of two times the last 10 minutes of the WHTC may be added to the adaptation run between the demonstration tests.

              6.5. Requirements for demonstrating the durability of a dual-fuel engine

           Provisions of Annex 7 shall apply.

              7. OBD requirements

              7.1. General OBD requirements

              All dual-fuel engines and vehicles shall comply with the requirements specified in Annex 9A and applicable to diesel engines, independent whether operating in dual-fuel or diesel mode.

              In case a dual-fuel engine system is equipped with oxygen sensor(s), the requirements applicable to gas engines in item 13. in Appendix 3 of Annex 9B shall apply.

              In case a dual-fuel engine system is equipped with a 3-way catalyst, the requirements applicable to gas engines in items 7., 10., and 15. in Appendix 3 of Annex 9B shall apply.

              7.1.1. Additional general OBD requirements in case of Type 1B, Type 2B and Type 3B dual-fuel engines and vehicles.

              7.1.1.1. In the case of malfunctions the detection of which does not depend on the operation mode of the engine, the mechanisms specified in Annex 9B that are associated with the DTC status shall not depend on the operation mode of the engine (for example, if a DTC reached the potential status in dual-fuel mode, it will get the confirmed and active status the next time the failure is detected, even in diesel mode).

              7.1.1.2. In the case of malfunctions where the detection depends on the operation mode of the engine, DTCs shall not get a previously active status in a different mode than the mode in which they reached the confirmed and active status.

              7.1.1.3. A change of the mode of operation (dual-fuel to diesel or vice-versa) shall not stop nor reset the OBD mechanisms (counters, etc.). However, in the case of failures the detection of which depends on the actual operation mode, the counters associated with these malfunctions 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 back to the other operation mode.

              7.1.1.4. 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.