On many models, control module regulates operation of the A/C clutch through an control module-controlled relay. The control module disengages the A/C compressor when compressor load on engine may cause driveability problems (i.e., during hot restart, idle, low speed steering maneuvers and wide open throttle operation) or if A/C refrigerant pressure drops to less than or rises to greater than normal operating levels.
Refrigerant pressure is sensed through the monitoring of high and low pressure switches or a pressure sensor which registers either high or low pressure levels. Hot restart is monitored through the coolant temperature sensor. For component application and related wiring, see wiring schematics under MISCELLANEOUS PCM CONTROLS in SYSTEM/COMPONENT TESTS - 4.3L article.