Method of determining ethanol thresholds in a flexible fueled vehicle
US5868117A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 29, 1997 |
| Grant date | Feb 9, 1999 |
| Priority date | — |
| Expiry date | Oct 29, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/30
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
The present invention provides a method for determining ethanol thresholds for a flexible fuel control system for a motor vehicle capable of operating on more than one type of fuel. Preferably, the ethanol threshold is determined from an off-idle purge-free cell from a matrix of fuel adaptive memory cells normally used to compensate for car-to-car variations in required fueling. The ethanol threshold is periodically reduced to compensate for levels of alcohol creep indicated by the amount of purge-free adaptive memory elevation. If the learned value of percent alcohol content of the fuel is less than the ethanol threshold, gasoline operating parameters are implemented for the internal combustion engine. The off-idle purge-free cell also provides a basis for interpolating an on-board diagnostic (OBDII) ethanol threshold. As such, the OBDII monitors are only enabled if the learned value of percent alcohol content of the fuel is less than the OBDII ethanol threshold.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.