The 2009 Nissan Sentra refrigerant flows in the standard pattern, that is, through the compressor, the condenser with liquid tank, through the evaporator, and back to the compressor. The refrigerant system is protected against excessively high or low pressures by the refrigerant pressure sensor, located on the liquid tank. The following schematic diagram shows detail flow/ cycle of the 2009 Nissan Sentra Refrigerant system. Legend: 1. Pressure relief valve, 2. Compressor, 3. Refrigerant pressure sensor, 4. Condenser (with liquid tank), 5. Expansion valve, 6. Evaporator, 7. Front blower motor.