| 摘要 |
PURPOSE:To facilitate inspection repair works by fixing the control mode for air-to-fuel ratio correction and actuating the alarm, when wire harness from an O2 sensor is disconnected, and by setting the air-to-fuel ratio in a condition with possibility to run. CONSTITUTION:The sensed value from an O2 sensor 1 is fed into an O2 sensor judgement device 3, and the output therefrom depending upon whether the mixture is rich or lean is put in an air-to-fuel ratio correction circuit 4 to serve for control of an air-to-fuel ratio actuator 4. The grounding wire 2 for O2 sensor is, connected to the abovementioned O2 sensor judgement device 3 and a running mode fixing circuit 6 and an alarm 7, and when the O2 sensor's grounding wire is disconnected, for ex. due to loose connection, a transistor 62 is turned on from a battery 8 through resistances 71, 61 and a transistor 73 through resistances 71, 72 to cause fixation of the control mode for air-to-fuel ratio correction. Then the alarm lamp 74 lights up. |
