Patent ID: 7293557
Filing Date: 2007-11-13
Classification: F02D

Abstract:
1. An abnormality detecting apparatus, comprising: an air/fuel ratio sensor that detects an air/fuel ratio within a range that includes the stoichiometric air/fuel ratio; an admittance detector that detects an admittance of the sensor; a temperature detector that detects a temperature of the sensor; and a controller that detects an abnormality of the sensor when the detected temperature of the sensor reaches a first temperature which is higher than an activation temperature of the sensor and the detected admittance is less than a first determining value, wherein the controller detects a disconnection abnormality of the sensor when the detected temperature of the sensor reaches a second temperature which is higher than a minimum temperature at which admittance can be detected when the sensor is operating normally, but is lower than the first temperature, and the detected admittance of the sensor is less than a second determining value for determining disconnection of the sensor.