Wagoneer L6-258 4.2L VIN C 2-bbl (1982)
Engine Control Module: Description and Operation
The MCU monitors the oxygen sensor voltage and, based upon the mode of operation, generates a control signal for the carburetor stepper motor.
When the system is in the closed loop mode, the air/fuel mixture will vary according to the oxygen content in the exhaust gas and the engine
operating conditions. When the system is in the open loop mode, the air/fuel mixture will be based on a predetermined ratio that is dependent on
several engine operating conditions.