Page 206 - Methods For Monitoring And Diagnosing The Efficiency Of Catalytic Converters A Patent - oriented Survey

188 Methods for Monitoring and Diagnosing the Eficiency of Catalytic Converters

Fig. 84 (from US5425234)

For the control of the engine operation, there is provided an electronic control unit (ECU)
having an input terminal to which an ignition coil composed of a boosting transformer and an
igniter constituted by a power transistor for interrupting electric conduction through a primary
winding of the ignition coil is connected. An idle switch which serves to detect the idling
operation state of the engine in which the throttle valve is fi.11ly closed is provided
integrally with the throttle sensor, wherein the output signals D and cp of both the idle switch
and the throttle sensor are supplied to the electronic control unit. Supplied additionally to
the electronic control unit are an output signal T of a thermistor-type water temperature
sensor which is employed for detecting the temperature T of the engine cooling water and an
output signal P of the pressure sensor mentioned above. An electric power for the electronic