Title:
【発明の名称】エンジンにおける酸素センサの劣化診断装置
Document Type and Number:
Japanese Patent JP3340330
Kind Code:
B2
Abstract:
In a heated type oxygen sensor having a sensing element responding to changes in the exhaust oxygen content and a heater inside, a diagnostic system for diagnosing deterioration of the heated type oxygen sensor comprises an electronic control unit being responsive to an engine temperature for discriminating whether the engine is in a cold-engine state or in a fully warmed-up state. The diagnostic system includes a first warm-up time setting circuit for setting a predetermined oxygen sensor's warm-up time at a first delay time which is preset to be suitable for the cold-engine state, during cold-engine operations, and a second warm-up time setting circuit for setting the predetermined oxygen sensor's warm-up time at a second delay time which is preprogrammed to be suitable for the fully warmed-up state, during fully warmed-up engine operations. The diagnostic system makes a diagnosis on deterioration of the oxygen sensor under a particular condition in which an elapsed time, measured from a time when the heater is turned on, reaches the predetermined oxygen sensor's warm-up time set depending on during cold-engine operation or during fully warmed up engine operation.
More Like This:
Inventors:
Shoichi Sakai
Application Number:
JP30038696A
Publication Date:
November 05, 2002
Filing Date:
November 12, 1996
Export Citation:
Assignee:
Unisia Jecs Co., Ltd.
International Classes:
G01M15/04; F01N9/00; F02B77/08; F02D41/14; F02D41/22; F02D45/00; (IPC1-7): F02D41/22; F01N9/00; F02B77/08; F02D41/14; F02D45/00; G01M15/00
Domestic Patent References:
| JP8271475A | ||||
| JP8285808A |
Attorney, Agent or Firm:
Fujio Sasashima