Device and method for measuring element temperature of air-fuel ratio sensor, and device and method for controlling heater of air-fuel ratio sensor
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Mar 30, 2004
Grant Date -
Jan 24, 2002
app pub date -
May 14, 2001
filing date -
May 17, 2000
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
A device according to the present invention is provided with element temperature measurement voltage application circuit for temporarily applying a predetermined voltage for element temperature measurement to a sensor element of an air-fuel ratio sensor equipped to an exhaust system of an internal combustion engine, first sensor output reading circuit for reading in a sensor output just before applied with the voltage, and second sensor output reading circuit for reading in a sensor output being applied with the voltage, wherein the element temperature of the air-fuel ratio sensor is estimated based on the sensor output just before applied with the voltage and the sensor output being applied with the voltage. Further, during internal resistance measurement of the sensor element of the air-fuel ratio sensor equipped to the exhaust system of the internal combustion engine, a voltage applied to the heater for heating the sensor element is maintained to be constant.
First Claim
Other Claims data not available
