CONTROL DEVICE OF GAS SENSOR

PROBLEM TO BE SOLVED: To provide a control device of a gas sensor capable of diagnosing accurately an abnormality of the gas sensor regardless of execution of preliminary energization to a heater of the gas sensor. SOLUTION: An elapsed time is counted by using as a start point, a start time of sensor activation energization for being energized to a ceramic heater 20, so that an oxygen pump cell 11 and an oxygen concentration measuring cell 15 reach an activation temperature or higher, regardless of executing of the preliminary energization (equivalent to energization for preventing crack of the gas sensor 1 caused by scattering of condensed water) for restricting energization to the ceramic heater 20. Then, a resistance value Rpvs of an element part 10 (to put it concretely, the oxygen concentration measuring cell 15) is compared with an abnormality threshold at the point of time when a prescribed time elapses from start of counting, to thereby diagnose existence of an abnormality of the gas sensor 1. COPYRIGHT: (C)2009,JPO&INPIT