Document ID: chunk:federal_register_of_legislation:F2023L00129:reg:99:p22
Version: federal_register_of_legislation:F2023L00129
Segment Type: reg
Provision Reference: reg 99 (pt 22/39)
Character Range: 1214677–1217839

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.

              7.1.1.5. In case of a Type 1B, Type 2B, or Type 3B dual-fuel engine, the manufacturer shall specify which malfunctions are operation mode dependent. This information shall be included in the information package required in paragraph 8.1. (a) of Annex 9B. The justification for operation mode dependency shall be included in the information package required in paragraph 8.1. (b) of Annex 9B.

              7.1.1.5. The following piece of information shall be added to table 1 in Appendix 5 of Annex 9B.

                                                                                                                         Freeze frame  Data stream
In case of Type 1B, Type 2B and Type 3B dual-fuel engines, operation mode of the Dual-fuel Engine (dual-fuel or diesel)  x             x

7.2. Monitoring of the gas supply system
              HDDF engines and vehicles shall monitor the gas supply system within the engine system (incl. the signals coming from outside of the engine system) according to the specifications of item 1. in Appendix 3 to Annex 9B – component monitoring.

              7.3. Monitoring of the gaseous fuel consumption

              Dual-fuel vehicles shall include a means of determining gas fuel consumption and providing off-board access to consumption information. Abnormality of the gaseous fuel consumption (e.g. a deviation of 50 per cent of the normal gaseous fuel consumption) shall be monitored – performance monitoring.

              The monitor for insufficient gaseous fuel consumption shall run continuously whenever in dual-fuel mode, however the maximum detection period is 48 hours of operation in dual-fuel mode.

           The monitor shall not be subject to the "IUPR" requirements.

7.4. OBD deficiencies
              The deficiency rules specified in Annex 9B and applicable to diesel engines shall apply to dual-fuel engines.

              A deficiency that is present both in diesel mode and in dual-fuel mode shall not be counted for each mode separately.

7.5. Erasing of failure information by means of a scan-tool
              7.5.1.  Erasing of information by means of a scan tool, including DTCs relative to the malfunctions considered in this annex shall be performed in accordance with Annex 9B.

              7.5.2. The erasing of failure information shall only be possible under "engine-off" conditions.

              7.5.3. When failure information related to the gas supply system as specified in paragraph 7.2., including the DTC, is erased, the counter associated with this failure shall not be erased.

8. Requirements to ensure the correct operation 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