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Refrigerant Pressure Sensor / Switch: Description and Operation

A/C PRESSURE SWITCHES

The A/C system is protected by two pressure switches. The A/C high pressure switch interrupts the A/C request signal when the A/C line pressure exceeds a predetermined value. The A/C low pressure switch interrupts the A/C low pressure switch signal when the A/C line pressure drops below a predetermined value. When the PCM stops receiving the required signals, the A/C compressor clutch relay control circuit is no longer grounded, thus shutting off the compressor.