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

The PCM controls the compressor clutch relay ground circuit.

The ignition circuit supplies battery voltage to the solenoid side of the relay.

When A/C or defrost is selected, (turned ON), inside vehicle, and low pressure, high pressure and ambient temperature switches are closed, PCM receives an A/C ON signal. PCM then supplies relay ground.

If PCM senses Wide Open Throttle (WOT) or low idle speed condition, it removes relay ground, discontinueing A/C clutch engagement.