Low purge flow vehicle diagnostic tool
US8630786B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 25, 2010 |
| Grant date | Jan 14, 2014 |
| Priority date | — |
| Expiry date | Apr 14, 2032 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/0037
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A vehicle includes an engine, a sealed fuel system having a fuel tank, a canister for storing fuel vapor, a vapor circuit external to the fuel tank, and a control valve. The vapor circuit includes an absolute pressure sensor and a switching valve connecting the fuel tank to the control valve. A controller evaluates or diagnoses a vapor purge function of the sealed fuel system using vacuum measurements from the absolute pressure sensor, executing or diagnosing only when the engine is running, purge is enabled, and the pump is off. The controller diagnoses the vapor purge function by comparing the vacuum measurements to a threshold vacuum. An apparatus includes the vapor circuit and controller. A method for diagnosing the vapor purge function includes actuating the switching valve, measuring a vacuum in the system using the absolute pressure sensor, and comparing the measured vacuum to a threshold vacuum.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.