| 摘要 |
PURPOSE:To enable easy detection of whether an air-fuel ratio sensor attains activating temp. or not with a device for using the air-fuel ratio sensor of which the output changes proportionally to the air-fuel ratio and subjecting the gaseous mixture taken into an engine to feedback control by setting the reference voltage of an oxygen sensor at an adequate value after the start of the engine. CONSTITUTION:The analog value of the information on an intake air flow is converted to a digital value by an AD converter 20 while feedback control by an air-fuel ratio sensor 2 is not performed. A microprocessor 21 reads out the preprogrammed procedure and constant from an ROM 22 and operates an optimum fuel feed rate. The result of the arithmetic fed via an output interface circuit 24 to a means 15 for forming a gaseous mixture corresponds to the driving pulse width of, for example, an electromagnetic fuel injection valve provided in the means 15, by which the air-fuel ratio in the means 15 is controlled. The correction by pump current Ip is further added to the arithmetic of the open loop control in which the feedback control is not executed, in the operating state in which the feedback control is performed in accordance with the output from the sensor 2. |
