A refrigerant circuit system, in particular a heat pump system, wherein the refrigerant circuit system has a refrigerant circuit, in which a refrigerant circulates and which is divided into a high-pressure area and a low-pressure area, wherein the refrigerant circuit system has a compressor for compressing the refrigerant arranged in the refrigerant circuit is provided. A pressure and temperature value of the refrigerant in the low-pressure area is measured by a pressure and temperature sensor arranged in the low-pressure area and then a pressure value of the refrigerant in the high-pressure area is determined by the measured pressure and temperature value and a provided compressor characteristic map of the compressor. A refrigerant circuit system for a vehicle is provided and is configured to carry out the method and a vehicle, in particular an electrically powered vehicle, which is equipped with such a refrigerant circuit system.