Gas sensor control device
US9890725B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 16, 2014 |
| Grant date | Feb 13, 2018 |
| Priority date | — |
| Expiry date | Sep 28, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N33/007
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A constant current circuit is controlled to stop a constant current Ics (Ics=0) flowing between sensor electrodes of an oxygen sensor, in a period before the oxygen sensor becomes active, during a fuel cut of an engine, and after the engine stops. When an abnormality (for example, a failure) occurs in the constant current circuit, a sensor output equivalent to an output of the oxygen sensor of when the constant current circuit is controlled to stop the constant current Ics is different from a normal sensor output. An abnormality diagnosis is executed to determine a presence or absence of the abnormality in the constant current circuit depending on whether the output of the oxygen sensor is out of a predetermined normal range, in a period before the oxygen sensor becomes active, during a fuel cut of an engine, and after the engine stops (when the constant current circuit is controlled to stop the constant current Ics).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.