Document ID: chunk:federal_register_of_legislation:F2024L00446:reg:13:p3
Version: federal_register_of_legislation:F2024L00446
Segment Type: reg
Provision Reference: reg 13 (pt 3/23)
Character Range: 1949856–1952911

to allow for the recognition of fuel quality and composition by the ECU;

                  (b) For bi fuel vehicles during 5 seconds after fuel switching to allow for readjusting engine parameters;

                  (c) The manufacturer may deviate from these time limits if it can demonstrate that stabilisation of the fuelling system after re-fuelling or fuel switching takes longer for justified technical reasons. In any case, the OBD system shall be re-enabled as soon as either the fuel quality and composition is recognised, or the engine parameters are readjusted.

              3.2.2. Engine misfire in vehicles equipped with positive ignition engines

              3.2.2.1. Manufacturers may adopt higher misfire percentage malfunction criteria than those declared to the authority, under specific engine speed and load conditions where it can be demonstrated to the authority that the detection of lower levels of misfire would be unreliable.

              3.2.2.2. When a manufacturer can demonstrate to the authority that the detection of higher levels of misfire percentages is still not feasible, or that misfire cannot be distinguished from other effects (e.g. rough roads, transmission shifts, after engine starting; etc.) the misfire monitoring system may be disabled when such conditions exist.

              3.2.3. Identification of deterioration or malfunctions may be also be done outside a driving cycle (e.g. after engine shutdown).

              3.3. Description of tests

              3.3.1. The tests are carried out on the vehicle used for the Type 5 durability test, given in Annex C4 to this Regulation, and using the test procedure in Appendix 1 to this annex. Tests are carried out at the conclusion of the Type 5 durability testing.

               When no Type 5 durability testing is carried out, or at the request of the manufacturer, a suitably aged and representative vehicle may be used for these OBD demonstration tests.

              3.3.2. The OBD system shall indicate the failure of an emission-related component or system when that failure results in emissions exceeding any of the OBD thresholds set out in paragraph 6.8.2. of this Regulation.

3.3.2.1. The OBD thresholds for vehicles that are type approved according to the emission limits set out in paragraph 6.3.10. of this Regulation are set out in Table 4A and Table 4B (as applicable) in paragraph 6.8.2. of this Regulation.
3.3.3. Monitoring requirements for vehicles equipped with positive ignition engines.
               In satisfying the requirements of paragraph 3.3.2. of this annex the OBD system shall, at a minimum, monitor for:

              3.3.3.1. The reduction in the efficiency of the catalytic converter with respect to emissions of NMHC and NOx. Manufacturers may monitor the front catalyst alone or in combination with the next catalyst(s) downstream. Each monitored catalyst or catalyst combination shall be considered malfunctioning when the emissions exceed the NMHC or NOx OBD thresholds set out in paragraph 6.8.2. of