Exhaust gas recirculation diagnostic
US5508926A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 24, 1994 |
| Grant date | Apr 16, 1996 |
| Priority date | — |
| Expiry date | Jun 24, 2014 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02M26/53
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
Restrictions in a path of flow of recirculated internal combustion engine exhaust gas from an engine exhaust system to an engine intake manifold are diagnosed when the engine is determined to be in a steady state operating condition through a monitoring of the air pressure in the engine intake manifold while the flow of exhaust gas thereto is varied according to a predetermined flow schedule. Changes in the monitored air pressure are determined over a test period, are filtered through a lag filter process having a dynamic filter coefficient, and are compared to a dynamic threshold to determine a presence of a restriction. The filter coefficient and the threshold may be adjusted in accord with the outcome of the diagnostic.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.