GAS SENSOR CONTROL APPARATUS

A sensor element 10 of an A/F sensor AS has a solid electrolyte layer 11, a first electrode 15 arranged on one side of the solid electrolyte layer 11 so as to be exposed to the exhaust gas of an internal combustion engine, and a second electrode 16 arranged on the other side of the solid electrolyte layer 11 so as to face an atmospheric air chamber 18. The sensor element 10 generates a sensor output according to the oxygen concentration in the exhaust gas. A microcomputer 20 supplies oxygen to the first electrode 15 side from the second electrode 16 side via the solid electrolyte layer 11 by applying a predetermined voltage between the pair of electrodes 15 and 16 of the sensor element 10. Moreover, the microcomputer 20 determines a crack abnormality of the solid electrolyte layer 11 based on electric current between the pair of electrodes 15 and 16 which is generated with start of the oxygen supply.