Patent ID: 11927120
Assignee: DENSO CORPORATION
Field: Environmental technology (Chemistry)
Classification: CPC F  Y | IPC F

Claim 8:
9. An exhaust gas sensor including:
a sensor element including a detector configured to detect a specific component contained in exhaust gas;
an element cover that accommodates the sensor element and includes one or more gas flow holes for letting the exhaust gas in and out of the element cover;
a heater configured to heat the sensor element when energized;
a controller configured to:
control how the heater heats the sensor element;
prior to diagnosing the state of the element cover using the heater information, diagnose a state of the element cover using heater information obtained when the heater is operated by the controller, wherein the diagnosis of the state of the element cover includes a determination of whether the state of the element cover is diagnosable based on whether the heater information is accurate, the heater information being obtained from an operating state of the heater and a surrounding environmental state of the element cover;
perform a first determination of whether the heater is ready to operate normally based on one of resistance value information on the heater serving as an index of the operating state of the heater or temperature information on the sensor element,
perform a second determination of whether the surrounding environmental state of the element cover is in a state that allows the state of the element cover to be diagnosed based on information on a part of the exhaust gas located around the element cover serving as an index of the surrounding environmental state of the element cover, and
determine that the heater information is accurate and the state of the element cover is diagnosable in response to determining that the heater is ready to operate normally based on a result of the first determination and determining that the surrounding environmental state of the element cover is in a state that allows the state of the element cover to be diagnosed based on a result of the second determination;
wherein the controller is further configured to determine that the heater is ready to operate normally in response to determining that a measured value of a heater resistance as the resistance value information on the heater is within a normal range which is set based on an initial value of the heater resistance, or determining that a calculated value of sensor temperature as the temperature information on the sensor element is within a normal range which is set based on a measured value of the sensor temperature, the calculated value of the sensor temperature being calculated based on the measured value of the heater resistance.