Document ID: chunk:federal_register_of_legislation:F2023C00229:reg:110:p30
Version: federal_register_of_legislation:F2023C00229
Segment Type: reg
Provision Reference: reg 110 (pt 30/59)
Character Range: 688403–691525

deNOx-particulate filter when such a system would not normally be active).

             3.1.3. OBD may involve devices, which measure, senses or responds to operating variables (e.g. vehicle speed, engine speed, gear used, temperature, intake pressure or any other parameter) for the purpose of detecting malfunctions and of minimising the risk of indicating false malfunction. These devices are not defeat devices.

             3.1.4. Access to the OBD system required for the inspection, diagnosis, servicing or repair of the engine must be unrestricted and standardised. All emis- sion related fault codes must be consistent with those described in section 6.8.5 of this Annex.

             3.2. OBD Stage 1 requirements

             3.2.1. From the dates given in Article 4(1) of this Directive, the OBD system of all diesel engines and of vehicles equipped with a diesel engine must indicate the failure of an emission-related component or system when that failure results in an increase in emissions above the appropriate OBD thresholds given in the table in Article 4(3) of this Directive.

             3.2.2. In satisfying the Stage 1 requirements, the OBD system must monitor for:

             3.2.2.1. complete removal of a catalyst, where fitted in a separate housing, that may or may not be part of a deNOx system or particulate filter.

             3.2.2.2. reduction in the efficiency of the deNOx system, where fitted, with respect to the emissions of NOx only.

             3.2.2.3. reduction in the efficiency of the particulate filter, where fitted, with respect to the emissions of particulate only.

             3.2.2.4. reduction in the efficiency of a combined deNOx-particulate filter system, where fitted, with respect to both the emissions of NOx and particulate.

             3.2.3. Major functional failure

             3.2.3.1. As an alternative to monitoring against the appropriate OBD threshold limits with respect to sections 3.2.2.1 to 3.2.2.4, OBD systems of diesel engines may in accordance with Article 4(1) of this Directive monitor for major functional failure of the following components:

                -          a catalyst, where fitted as a separate unit, that may or may not be part of a deNOx system or particulate filter

                -          a deNOx system, where fitted

                -          a particulate filter, where fitted

                -          a combined deNOx-particulate filter system.

             3.2.3.2. In the case of an engine equipped with a deNOx system, examples of monitoring for major functional failure are for complete removal of the system or replacement of the system by a bogus system (both intentional major functional failure), lack of required reagent for a deNOx system, failure of any SCR electrical component, any electrical failure of a component (e.g. sensors and actuators, dosing control unit) of a deNOx system including, when applicable, the reagent heating system, failure of the reagent dosing system (e.g. missing air supply, clogged nozzle, dosing pump failure).

             3.2.3.3. In the case of an