Amigo 4WD L4-2.3L (4ZD1) (1989)
Mixture Control Solenoid: Description and Operation
Duty Solenoid
The duty solenoid is an integral part of the carburetor. Responding to various input signals (oxygen sensor, engine speed, coolant temperature, etc.), the
ECM controls the continuous on and off cycling (duty cycle) of this solenoid. Also referred to as the mixture control solenoid, it opens and closes the
carburetor main metering circuit, thus making ECM directed air/fuel ratio adjustments.
The ECM duty cycle control signal is selected from four operational modes:
1.
Inhibit mode: Fixed control signal to duty solenoid.
2.
WOT (wide open throttle) mode: Pre-programmed duty cycle generated based on engine RPM.
3.
Open loop mode: Pre-programmed duty cycle generated based on various parameters (cold oxygen sensor, for example).
4.
Closed loop mode: Calculated duty cycle generated based on oxygen sensor and other sensor outputs.