Radiator Fan is not strong enough to reduce engine temperature

Hello... my XC90'04 T6 radiator's fan seems to be starting and keeping at a slow speed, let's say about 35%, even when the engine temperature is about 220oF or 230oF (yes... that high). When connected to a scanner, it is able to manually set higher speeds and putting it to 85% it is able to reduce engine temperature in about 1 or 2 minutes to normal. What could it be wrong?
I would say it is the fan, the relay or the line, but as I mentioned above, using the scanner I am able to manually set the fan speed to a good speed. The car by itself is not able to do it. Any idea?

Thanks in advance!