Toyota Jidosha Kabushiki Kaisha

Yasutaka Kamiya

Keiichiro Aoki

Kazuhiro Wakao

Yoshiyuki Kitazume

An abnormality detection device for an air-fuel ratio detection device arranged downstream of a filter is equipped with an abnormality detection unit that detects an abnormality in the air-fuel ratio detection device based on output change characteristics of the air-fuel ratio detection device during fuel cutoff control for stopping the supply of fuel to a combustion chamber of an internal combustion engine, and a combustion determination unit that determines whether or not a combustion amount of particulate matter in a filter during fuel cutoff control is larger than a predetermined amount. The abnormality detection unit prohibits detection of an abnormality in the air-fuel ratio detection device when the combustion determination unit determines that the combustion amount is larger than the predetermined amount.

Abnormality detection device for air-fuel ratio detection device

The abnormality diagnosis systemof a downstream side air-fuel ratio detection device, comprises an air-fuel ratio control partcontrolling an air-fuel ratio of an air-fuel mixture, an abnormality judgment partjudging abnormality of the downstream side air-fuel ratio detection device based on a characteristic of change of output of the downstream side air-fuel ratio detection device when the air-fuel ratio control part makes the air-fuel ratio of the air-fuel mixture change, and an oxygen change calculation partcalculating an amount of change of an oxygen storage amount of the catalyst when the air-fuel ratio control part makes the air-fuel ratio of the air-fuel mixture change. The abnormality judgment part does not judge abnormality of the downstream side air-fuel ratio detection device when the amount of change of the oxygen storage amount is less than a lower limit threshold value.

Abnormality diagnosis system of downstream side air-fuel ratio detection device

A control device for an exhaust sensor is configured to control the exhaust sensor disposed in an exhaust passage of an internal combustion engine. The control device for an exhaust sensor includes: a sensor element; a heater configured to heat the sensor element; a current detection circuit configured to detect an output current of the exhaust sensor, and an electronic control device configured to control electric power that is supplied to the heater by PWM control.

Growing community of inventors

Inazawa, Japan

Yasutaka Kamiya