Document ID: chunk:federal_register_of_legislation:F2023L00129:reg:99:p28
Version: federal_register_of_legislation:F2023L00129
Segment Type: reg
Provision Reference: reg 99 (pt 28/39)
Character Range: 1232516–1235332

(see paragraph A.2.1.2.3.2.1).

       A malfunction of the gas supply is again detected while the gas supply malfunction counter is at zero (1st detection).

       The service mode is activated and the counter starts counting once the DTC gets the "confirmed and active" status (2nd detection).

       After 30 minutes of operation without a standstill situation, the service mode becomes active and the vehicle speed is limited to 20 km/h (see paragraph 4.2.2.1 of this annex).

       The counter freezes at a value of 30 minutes operating time.

              A.2.2. Illustration of the other activation and deactivation mechanisms

              A.2.2.1. Empty gas tank

              Figure A2.2 gives an illustration of the events occurring in the case of a HDDF vehicle when a gas tank becomes empty through one typical use-case.

Figure A2.2
Illustration of the events occurring in case of an empty gas tank (Types A and B HDDF)
 In that use case:
                  (a) The warning system specified in paragraph 4.3.2. of becomes active when the level of gas reaches the critical level defined by the manufacturer;

                  (b) The service mode is activated (in the case of a Type A HDDF) or the engine switches to Diesel mode (in the case of a Type B HDDF).

              In the case of a Type A HDDF, the service mode becomes active and the vehicle speed is limited to 20 km/h after the next time the vehicle is stationary or after 30 minutes operating time without standstill (see paragraph 4.2.2.1. of this annex).

              The gas tank is refilled.

              The vehicle operates again in dual-fuel mode as soon as the tank is refilled above the critical level.

       A.2.2.2. Malfunctioning gas supply

              Figure A2.3 gives via one typical use-case an illustration of the events occurring in the case of a malfunction of the gas supply system. This illustration should be understood as complementary to that given in section A.2.1 and dealing with the counter mechanism.

Figure A2.3
Illustration of the events occurring in case of a malfunctioning gas supply system (Types A and B HDDF)
 In that use case:
(a) The failure of the gas supply system occurs for the very first time. The DTC gets the potential status (1st detection);
                  (b) The service mode is activated (in the case of a Type A HDDF) or the engine switches to Diesel mode (in the case of a Type B HDDF) as soon as the DTC gets the "confirmed and active" status (2nd detection).

              In the case of a Type A HDDF, the service mode becomes active and the vehicle speed is limited to 20 km/h after the next time the vehicle is stationary or after 30 minutes operating time without standstill (see paragraph 4.2.2.1 of this annex).

              The vehicle operates again in