| 摘要 |
<p>PURPOSE:To improve fault diagnosis accuracy of secondary air supply by diagnosing a fault in an internal combustion engine within a plurality of operating ranges, after detecting the operating condition of the internal combustion engine, and judging the fault of a secondary air supplier in accordance with the output of the respective fault diagnoses of the respective operating ranges. CONSTITUTION:Control device 112 respectively controls an ISCV(idling speed control valve) 111, an ignition plug 113 and a fuel injection valve 114 based on respective detected signals from respective sensors 102, 104, 109, 110 for respectively detecting the operating condition of an internal combustion engine. It also respectively controls a pump 120, which composes a secondary air supply, respective valves 121, 122, 123, and secondary air induced from an introduction hole 116 to an exhaust gas passage 115. It further diagnoses a fault in the internal combustion engine 101. In this case, the control device 112 diagnoses the fault in the secondary air supply in accordance with output of the respective fault diagnoses in respective operating ranges of the internal combustion engine. In other words, the fault is judged by either choosing the logic of respective faults diagnosis output or the logical product of the output or by combining the logical product and the logical sum.</p> |
