| 摘要 |
<P>PROBLEM TO BE SOLVED: To reconcile early activation of an exhaust gas sensor with element crack prevention by heightening accuracy of a heater energization delay time until start of heater energization of the exhaust gas sensor after being started. <P>SOLUTION: A reference heater energization delay time is set corresponding to start conditions (a shift range, a cooling water temperature, an intake temperature, an outside air temperature, an oil temperature or the like) when being started, and an extended delay time is set corresponding to an operation condition after being started, and the extended delay time is added to the reference heater energization delay time to set the final heater energization delay time. Energization to heaters 27, 28 of exhaust gas sensors 25, 26 is prohibited until an elapsed time after being started reaches the final heater energization delay time, and when the elapsed time after being started reaches the final heater energization delay time, energization to the heaters 27, 28 of the exhaust gas sensors 25, 26 is started to start heating of a sensor element. <P>COPYRIGHT: (C)2009,JPO&INPIT |
