Compressor Clutch Relay: Description and Operation

The ECM controls the A/C compressor clutch relay. When the A/C is turned on, the ECM delays the clutch engagement of the A/C compressor to allow the IAC valve to raise the engine idle speed to compensate for the added load. The ECM also causes the relay to disengage the A/C clutch at wide open throttle and during high pressure power steering pump loads.