Refrigerant Pressure Sensor
WARNING: This page is about a different car, the 2013 Infiniti FX50. However, it is still accessible from the selected car via links, so may be relevant.
The refrigerant system is protected against excessively high- or low-pressures by the refrigerant pressure sensor, located on the liquid tank. The refrigerant pressure sensor detects the pressure inside the refrigerant line and sends the voltage signal to the ECM if the system pressure rises above, or falls below the specifications.
The high-pressure side detected by refrigerant pressure sensor is approximately 3, 120 kPa (31.8 kg/cm2 , 452 psi) or more when the engine speed is 1500 RPM or more. It is approximately 2, 740 kPa (27.9 kg/cm2 , 397 psi) when the engine speed is less than 1, 500 RPM. When it is approximately 120 kPa (1.2 kg/cm2 , 17 psi) or less, ECM turns the A/C relay to OFF and stops the compressor.