| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To perform abnormality diagnosis of a secondary air supply system of a vehicle brought in a service shop or the like irrespective of a temperature condition of an engine. <P>SOLUTION: A service person connects an off-board diagnosis device 38 to a diagnosis connector of ECU 37, turns an ignition switch on, operates the off-board diagnosis device 38 to input off-board diagnosis execution signal into the ECU 37 while stopping the engine 11 under a condition keeping power supply to the secondary air supply system enabled at the service shop or the like. Consequently, the ECU 37 starts operation of an air pump 31 and opens a control valve 35 to start supply of secondary air. Secondary air pressure Ps is detected by a pressure sensor 36 under this condition, then the control valve 35 is closed and secondary air pressure Po is detected by the pressure sensor 36, a normal/abnormal condition of the secondary air supply system 30 is determined based on whether pressure difference thereof (Po-Ps) is a criterion or greater. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
