Malfunction diagnostic apparatus and malfunction diagnostic method for intake air temperature sensors
US8428853B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 25, 2009 |
| Grant date | Apr 23, 2013 |
| Priority date | — |
| Expiry date | Mar 12, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01K2205/02
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A malfunction diagnostic apparatus for intake air temperature sensors includes a coolant temperature sensor; a first determination portion that determines that a precondition for performing a malfunction diagnosis is satisfied when a process of starting an engine is started, if a detected coolant temperature is determined to be equal to an intake air temperature detected by an intake air temperature sensor provided at a portion that is likely to be cooled, and a decrease amount, by which the detected coolant temperature decreases, is equal to or larger than a preset value; a second determination portion that makes a tentative determination based on a difference between the detected intake air temperatures, if the precondition is satisfied; and a third determination portion that determines whether the tentative determination is an invalid determination or a valid determination, based on a change in the detected intake air temperatures during a given time period.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.