A/C Signal: Description and Operation
CONDITIONSA/C or defrost switch is turned ON.
A/C low pressure, and high pressure switches are closed.
OPERATION
^ Powertrain Control Module (PCM) receives an A/C selected signal.
^ PCM then engages A/C compressor clutch (by grounding clutch relay).
^ PCM maintains correct engine idle speed, through the Idle Air Control (IAC) Motor.
^ PCM monitors status of switches and cycles compressor clutch accordingly.