What should I do if the air conditioner of Mercedes-Benz S350 doesn't cool and blow hot air?

The mechanical part of the air conditioning system I assembled for Mercedes-Benz S-Class 2003 car consists of variable frequency compressor, condenser, liquid storage drying tank, expansion valve and evaporator. The electric control part consists of air conditioning panel (air conditioning controller), temperature sensors inside and outside the carriage, multifunctional gas sensor, sunlight sensor, left and right air outlet temperature sensors, refrigerant pressure sensor, refrigerant temperature sensor, blower, damper control unit and various electric control dampers. First, check whether the refrigerant pressure leaks, whether there is ice resistance in the evaporation box and whether the expansion valve is blocked. Secondly, check whether the temperature control valve is abnormal, resulting in no change in the flow of antifreeze distributed by the warm air small water tank, which leads to an increase in temperature. Check the temperature control valve and circuit for poor signal and virtual connection. Secondly, check whether the temperature sensor, sunlight sensor and electric damper are stuck. Secondly, check whether there is any problem with the air conditioning panel and control unit. First of all, determine whether the water temperature is high when driving, resulting in poor air conditioning. Check whether there is any problem with the electronic fan and controller, and whether the electronic fan has no high speed.