Yeti 1.8 TSI radiator fans speeds

Hello everyone,

I want to ask about the radiator fan on my Yeti 1.8TSI. 2010. The fans have two speeds i guess, the second speed comes on when the ambient temp Is high (above 35c), but its not that much of a higher speed than the low one. Tried to check by removing the radiator temp sensor/switch and the fans came on hard, very high speed. So tried then to replace the water temperature switch but same result, that very high speed does not come again. I am asking because my AC is not cool enough when the ambient temp gets high, and i went to a workshop who checked everything and said the AC system is fine. 

How much speeds does the radiator’s fan have? Two or three? And would the fan controller thats inside the big fan controls the speeds?? So i should replace it??

Any feedback would be much appreciated. Thank you in advance