| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a heater failure determination method of an air-fuel ratio sensor and a device therefor capable of performing failure determination of a heater attached to a detection element of the air-fuel ratio sensor installed in an exhaust pipe of an internal combustion engine, in a short time without damaging the detection element even at a low temperature time having probability of spattering of water. <P>SOLUTION: In this heater failure determination method of the air-fuel ratio sensor comprising the gas concentration detection element and the heater for heating the gas concentration detection element, when an exhaust temperature is lower than a temperature at which there is probability of spattering of water over the gas concentration detection element, an energization current amount and an energizing time to the heater are adjusted below a limited energization current amount and within a limited energizing time which are set corresponding to the exhaust temperature, and existence of an energization current at the energizing time to the heater is detected, and a failure of the heater is determined based on existence of the energization current. <P>COPYRIGHT: (C)2008,JPO&INPIT |
