Compressor Clutch Relay: Description and Operation

Relay Identification:

Purpose

Powertrain Control Module (PCM) monitors engine load and A/C system pressure, and cycles the A/C compressor clutch accordingly.

Operation

A/C or defrost switch is turned ON.

A/C low pressure, high pressure and electronic cycling 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.