A/C Refrigerant Pressure Sensor

The A/C system is protected by the A/C refrigerant pressure sensor. The sensor is mounted on the discharge line of the A/C compressor hose assembly. The sensors' output to the PCM is variable and is dependent upon pressure inside the line. A higher pressure results in a higher voltage output. The A/C pressure is constantly monitored in order to allow the A/C compressor clutch to disengage as needed. If line pressures climb above 2968 kPa (430 psi) or fall below 255 kPa (35 psi), the PCM will turn off the A/C compressor clutch.

A 5-volt reference signal is sent out over the 5-volt reference circuit, from the PCM to the A/C refrigerant pressure sensor. The PCM monitors the A/C pressure by emitting a 5-volt signal on the A/C pressure sensor signal circuit. The PCM monitors HVAC pressures from this circuit. Ground for the A/C refrigerant pressure sensor is provided by the low reference circuit.