| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a fault diagnosis device for an exhaust gas sensor, capable of precisely diagnosing faults caused by an element crack in the exhaust gas sensor, as to the fault diagnosis device for the exhaust gas sensor. <P>SOLUTION: The fault diagnosis device for the exhaust gas sensor includes a fault diagnosis means for diagnosing the fault of the element crack in the sensor, based on an output signal from the sensor, and a permission means for permitting the execution of the fault diagnosis when a diagnostic condition for the fault diagnosis is satisfied. The fault diagnosis means can execute the fault diagnosis only after permitted by the permission means, and the permission is prohibited by the permission means during a period where exhaust gas is clean. The fault diagnosis is permitted to be executed when an integrated value of an intake air volume is a prescribed value or more. The permission by the permission means is canceled when a state of bringing the integrated value of the intake air volume into the prescribed value or less continues for a prescribed time after the permission by the permission means. <P>COPYRIGHT: (C)2008,JPO&INPIT |
