| 摘要 |
<p>PURPOSE:To prevent harmful exhaust gas from being continuously discharge by providing an abnormality detection circuit which judges that a device is failed if there exists no change in 'ON/'OFF' electric signals, instantly judging that the device is failed, and thereby repairing the device thereafter. CONSTITUTION:Switching elements 41 and 42 are provided, which convert the 'ON/'OFF' action of a lead valve 4 acting as a secondary air intake device into the 'ON/'OFF' action of electric signals, and furthermore into the 'ON /OFF' electric signals. When no change in electric signals by the switching elements 41 and 42 is found, that is, when no 'ON/'OFF' signal is generated, the lead valve is judged by the circuit 9 to be abnormal. By this constitution, the failed lead valve 4 is instantly repaired, and it is thereby possible to prevent harmful exhaust gas from being continuously discharged.</p> |
