Usually, the refrigerant used in automotive air conditioning systems is the R-134a refrigerant. At any rate, you should still check the owner's manual just to make sure.
To check if there is enough refrigerant for your air conditioner, you will have to measure the refrigerant pressure in the air conditioning system. To do so, you will need a particular refrigeration pressure gauge. If you use the R-134a refrigerant, the pressure levels must be the ones stated in the following chart:
You will have to measure these values while the engine is running and the air conditioner is on. A professional should be the one who does this.
If the pressure levels of your Cadenza are not within this range, you will have to recharge the refrigerant.
The air conditioning system differs from car to car. The amount of refrigerant is crucial for the correct functioning of the system, and it is usually around 1 to 1.5 pounds. If you want to know how much refrigerant you need for your car’s system, please read the owner's manual.