air-conditioning

Good, I have a Seat Toledo III, I have a problem in the air conditioning (Bi-Zona air conditioning)
the air works well but after a while, sometimes more sometimes less, the habitaculus begins to rise temperature despite the fact that the air is still underway. The venilator motorcycle is running but the air does not come out through the nozzles or any other room outlet.
Would anyone know where the problem can be? I have reset and updated the air conditioner but nothing.
They have told me about a valve that is blocked but I don't know which one is gone to the technical service and they ask me to change everything. I have put gas and proven the circuit

They also refer to the expansion valve. This is in the motor compartment (you can visit Pag. Areavag) Treating a similar problem
www.areaavag.com/foro/showthread.php?830-...Passat-a4-A6-(Fotos)

I hope it helps you. Greetings!!