A/C Pressure Sensor

The A/C pressure sensor is mounted in the A/C high side pressure line. The sensor acts like a potentiometer and is used to indicate refrigerant pressure in the high side line. The PCM provides a 5 volt reference and ground to the sensor. The sensor feeds back a voltage signal that is proportional to A/C high side pressure. This information is used by the PCM to determine the amount of load the A/C compressor is putting on the engine. The range of the sensor is approximately zero (0) psi at 0.10 volts to 459 psi at 4.9 volts. Pressure gauges should be used to determine actual A/C system pressures.