A/C Signal: Description and Operation

Purpose

The Control Module monitors engine load and A/C system pressure, and cycles the A/C compressor clutch accordingly.

Operation

A/C or defrost and blower switches are ON, and A/C low pressure, high pressure and ambient temperature switches are closed.


- 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.