| 摘要 |
<P>PROBLEM TO BE SOLVED: To easily specify whether the trouble, caused in an apparatus is short circuiting caused at the outside of the port of a control unit or a trouble of the switching element in the control unit, in the control system of a sensor element. <P>SOLUTION: An oxygen sensor 10 and the control unit 20, connected to the oxygen sensor 10 by signal wires via terminals 22 and 24 are provided. When the output abnormality of the oxygen sensor 10 is detected (step 100), a second switch 42 is set to ON-state (step 102). At this time, when the output voltage of a second AD converter 46 is higher than that of a first A/D converter 38, the location of trouble is specified as being caused by the short-circuiting trouble of the external signal wires of the control unit 20 (step 108). Further, when the output voltage of the first A/D converter 38 is higher than that of the second A/D converter 46, the location of trouble is specified as being the occurrence of trouble, where the first switching element 26 is set turned ON (step 110) at all times. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
