LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Jeep >> 1983 >> Cherokee Base, 4.2 C, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> 4.2L Feedback Carburetor System >> Operation >> Microcomputer Control Unit >> Closed Loop
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Closed Loop

When all input data and engine operation meet programmed criteria (when OL1, OL2, OL3, OL4 and cold start modes are not selected and start-up timer has deactivated), the CEC system goes into closed loop operation. In this mode, oxygen sensor input signals are accepted by MCU to determine proper air/fuel mixture based upon oxygen content of exhaust gases. Air injection is routed "downstream" during this mode for partial or wide open throttle conditions and both "upstream" and "downstream" for all other throttle positions.

NOTE: Closed loop operation is characterized by constant movement of the metering pins. The MCU is constantly making small corrections in air/fuel ratio in an attempt to create the ideal air/fuel ratio.
scientia non olet · About LEMON Manuals