A/C Pressure Sensor

The A/C pressure sensor is a 3 wire piezoelectric pressure transducer. A 5-volt reference, low reference, and signal circuits enable the sensor to operate. The A/C pressure signal can be 0-5 volts. When the A/C refrigerant pressure is low, the signal value is near zero volts. When the A/C refrigerant pressure is high, the signal value is near 5 volts.

The A/C pressure sensor protects the A/C system from operating when an excessively high or low pressure condition exists. The Engine Control Module (ECM) disables the compressor clutch if A/C pressure is more than 428 psi (2951 kPa). The clutch will be enabled after the pressure decreases to less than 300 psi (2068 kPa). A/C high side pressure is less than 44 psi (310 kPa). The clutch will be enabled after the A/C high side pressure increases to more than 44 psi (310 kPa).