Techniques for monitoring purge flow and detecting vapor canister leaks in an evaporative emissions system
US9970391B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 25, 2016 |
| Grant date | May 15, 2018 |
| Priority date | — |
| Expiry date | Nov 30, 2036 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D2041/225
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A diagnostic method and system includes a control valve configured to control an amount of air drawn into an evaporative emissions (EVAP) system through an air filter and a vapor canister, and a pressure sensor configured to measure pressure in the EVAP system. The system also includes a controller configured to detect an engine idle-to-off transition and, in response to detecting the engine idle-to-off transition: receive a first pressure from the pressure sensor, fully open a purge valve connected between the vapor canister and an intake port of an engine, fully close the control valve, monitor one or more second pressures received from the pressure sensor, and detect a malfunction of the EVAP system based on the first pressure, at least one of the one or more second pressures, and a diagnostic threshold.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.