Document ID: chunk:federal_register_of_legislation:F2024C00356:reg:7:p26
Version: federal_register_of_legislation:F2024C00356
Segment Type: reg
Provision Reference: reg 7 (pt 26/51)
Character Range: 607063–610127

more than once per driving cycle.
              7.5. General Denominator
              7.5.1. The general denominator is a counter measuring the number of times a vehicle has been operated. It shall be incremented within 10 seconds, if and only if, the following criteria are satisfied on a single driving cycle:
               (a) Cumulative time since engine start is greater than or equal  to 600 seconds while at an elevation of less than 2,440 m above sea               level and at an ambient temperature of greater than or equal to
               -7° C;
               (b) Cumulative vehicle operation at or above 40 km/h occurs for greater  than or equal to 300 seconds while at an elevation of less than               2,440 m above sea level and at an ambient temperature of greater               than or equal to -7 °C;
               (c) Continuous vehicle operation at idle (i.e. accelerator pedal released  by driver and vehicle speed less than or equal to 1.6 km/h) for greater               than or equal to 30 seconds while at an elevation of less than 2,440 m               above sea level and at an ambient temperature of greater than or               equal to -7 °C.
              7.6. Reporting and increasing counters
              7.6.1. The OBD system shall report in accordance with the ISO 15031-5 specifications the ignition cycle counter and general denominator as well as separate numerators and denominators for the following monitors, if their presence on the vehicle is required by this annex:
 (a) Catalysts (each bank to be reported separately);
 (b) Oxygen/exhaust gas sensors, including secondary oxygen sensors  (each sensor to be reported separately);
 (c) Evaporative system;
 (d) EGR system;
 (e) VVT system;
 (f) Secondary air system;
 (g) Particulate filter;
 (h) NOx after-treatment system (e.g. NOx adsorber, NOx reagent/ catalyst system);
               (i) Boost pressure control system.
              7.6.2. For specific components or systems that have multiple monitors, which are required to be reported by this paragraph (e.g. oxygen sensor bank 1 may have multiple monitors for sensor response or other sensor characteristics), the OBD system shall separately track numerators and denominators for each of the specific monitors and report only the corresponding numerator and denominator for the specific monitor that has the lowest numerical ratio. If two or more specific monitors have identical ratios, the corresponding numerator and denominator for the specific monitor that has the highest denominator shall be reported for the specific component.
              7.6.3. All counters, when incremented, shall be incremented by an integer of one.
              7.6.4. The minimum value of each counter is 0, the maximum value shall not be less than 65,535, notwithstanding any other requirements on standardised storage and reporting of the OBD system.
              7.6.5. If either the numerator or denominator for a specific monitor reaches its maximum value, both counters for that specific monitor shall be