Refrigerant Pressure Sensor / Switch: Description and Operation

The Air Conditioning (A/C) refrigerant pressure sensor provides a signal to the Powertrain Control Module (PCM) which indicates varying high side refrigerant pressure between approximately 0 psi and 450 psi.

The PCM uses this input in order to determine the A/C compressor load on the engine in order to help control idle speed with the IAC valve.

The A/C refrigerant pressure sensor electrical circuit consists of a 5 volt reference line and a ground line, both provided by the PCM, and a signal line to the PCM. The signal is a voltage that varies from approximately 0.1 volt at 0 psi, to 4.9 volts at 450 psi or more. A problem in the A/C refrigerant pressure circuits or sensor may set a DTC P0530 and will make the A/C compressor inoperative.