Document ID: chunk:federal_register_of_legislation:F2024L00446:front:0:p17
Version: federal_register_of_legislation:F2024L00446
Segment Type: other
Provision Reference: 
Character Range: 49766–52688

fuel tank system pressure relief exclusively through the carbon canister allowed by the system.
3.9.11. "Depressurisation puff loss overflow" are the depressurisation puff loss hydrocarbons that pass through the carbon canister during depressurisation.
3.9.12. "Fuel tank relief pressure" is the minimum pressure value at which the sealed fuel tank system starts venting in response only to pressure inside the tank.
3.9.13. "2 gram breakthrough" shall be considered accomplished when the cumulative quantity of hydrocarbons emitted from the activated carbon canister equals 2 grams.
3.10. On-Board Diagnostics (OBD)
3.10.1. "On-Board Diagnostic (OBD) system" means in context of this Regulation, a system on-board the vehicle which has the capability of detecting malfunctions of the monitored emission control systems, identifying the likely area of a malfunction by means of fault codes stored in computer memory, and illumination of the Malfunction Indicator (MI) to notify the operator of the vehicle.
3.10.2. "OBD family" means a manufacturer's grouping of vehicles which, through their design, are expected to have similar exhaust emission and OBD system characteristics. Each vehicle of this family shall have complied with the requirements of this Regulation as defined in paragraph 6.8.1.
3.10.3. "Emission control system" means in the context of OBD the electronic engine management controller and any emission-related component in the exhaust or evaporative system which supplies an input to or receives an output from this controller.
3.10.4. "Malfunction indicator (MI)" means a visible or audible indicator that clearly informs the driver of the vehicle in the event of a malfunction of any emission-related component connected to the OBD system, or the OBD system itself.
3.10.5. "Malfunction" means the failure of an emission-related component or system that would result in emissions exceeding the OBD thresholds in paragraph 6.8.2. or if the OBD system is unable to fulfil the basic monitoring requirements of Annex C5.
3.10.6. "Secondary air" refers to air introduced into the exhaust system by means of a pump or aspirator valve or other means that is intended to aid in the oxidation of HC and CO contained in the exhaust gas stream.
3.10.7. "Engine misfire" means lack of combustion in the cylinder of a positive ignition engine due to absence of spark, poor fuel metering, poor compression or any other cause. In terms of OBD monitoring it is that percentage of misfires out of a total number of firing events (as declared by the manufacturer) that would result in emissions exceeding the OBD thresholds given in paragraph 6.8.2. or that percentage that could lead to an exhaust catalyst, or catalysts, overheating causing irreversible damage.
3.10.8. An "OBD driving cycle" consists of key-on, a driving mode where a malfunction would be detected if present, and key-off.
3.10.9. A "warm-up cycle"