Problem with the automatic air conditioning of my Peugeot 307

Hello, my 307 HDI 2006 modem Premium car has an automatic duplex air conditioner, it can give the right side a separate temperature to the left side.

Doesn't anyone have an idea? There was an engine that regulated the air passage, I think there was a problem with his gears. At least which master can I show? I am open to advice. & Nbsp;