| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent erroneous determination of normality/abnormality of a secondary air supply system due to reduction of pump performance accompanying with rise of temperature of an air pump in the secondary air supply system provided with the air pump for supplying secondary air to the upstream side more than catalyst for purifying exhaust gas. <P>SOLUTION: Temperature of the air pump 18 is inferred based on amount of sucked air and driving time and temperature of intake air (or temperature of outside air) of the air pump 18 used as substitute information of exhaust heat of an engine during a period of abnormality diagnosis of the secondary air supply system 17 to calculate an average value of temperature of the air pump. A determining value of normality/abnormality of the secondary air supply system 17 is set in accordance with the average value of temperature of the air pump during the period of abnormality diagnosis. An average value of secondary air pressure during the period of abnormality diagnosis is compared with the determining value to determine normality/abnormality of the secondary air supply system 17. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
