A/C Clutch: Notes
WARNING: This page is about a different car, the 2003 Saturn LW300 and 2003 Saturn L300. However, it is still accessible from the selected car via links, so may be relevant.
On most models, ECM regulates operation of the A/C clutch through a relay. The ECM 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/or low pressure switch(es) or a pressure sensor which registers either high or low pressure levels. Hot restart is monitored through the Engine Coolant Temperature (ECT) sensor. For component application and related wiring, see appropriate A/C COMPRESSOR CLUTCH CONTROLS article in HVAC.