| 摘要 |
<P>PROBLEM TO BE SOLVED: To specify the abnormal form of a gas concentration sensor, especially the short abnormality between both positive and negative terminals of the sensor. <P>SOLUTION: The sensor element 10 of an A/F sensor is connected to an engine ECU20 through a T1 terminal and a T2 terminal. In the engine ECU20, voltage is applied to the sensor element 10 at the time of detection of A/F and the element current flowing accompanied by the application of voltage is measured as A/F output voltage AFO. Further, the respective voltages VS+ and VS- of the T1 and T2 terminals are respectively measured. A CPU30 detects the short abnormality between the T1 and T2 terminals from that the respective voltages VS+ and VS- of the T1 and T2 terminals are the same value, the terminal voltages become values in an applied voltage control range and the A/F output voltage AFO is an abnormal value. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
