| 摘要 |
<p>An air/fuel ratio control system for use with an internal combustion engine, which comprises O2 sensor activation determining means having a comparator and a timer and adapted to determine the activation of an O2 sensor for detecting oxygen concentration in engine exhaust gases, to produce an output upon determining the activation, engine temperature determining means adapted to produce an output when an engine temperature detected by an engine temperature sensor exceeds a predetermined value, and signal generating means adapted to produce a feedback control initiating signal when supplied with both of the above outputs, whereby air/fuel ratio control operation can be initiated at an appropriate time. Further provided is means for supplying secondary air to the exhaust system of the engine, which is arranged to be rendered inoperative by the above feedback control initiating signal. Also provided is failure determining means which is operable to produce an output after the engine temperature determining means has continued producing its output for a predetermined period of time when no output is produced by the O2 sensor activation determining means.</p> |
