Ducato 120, 160, error P0638 throttle valve

Hello, you need your help with my Fiat Duc Womos. BBj.08/2008 with Multijet 160 3.0L engine 115KW. It lights up the jam lamp for engine and the error code P0638 throttle flap is in the memory. After deletion and twice starting the error comes again. Can you actually start from a defective DK and an exchange removes the error or there are other possibilities. The friendly wants in exchange 419 Euronen for the DK. In the net offer dealer a flap with un I had already removed and cleaned the flap, it is also easy to run. What would you advise me to do? Oh, I almost forgot to learn the new flap when swapping or does it work like that? I would be very grateful for quick feedback. In the appendix a picture of the type plate of the built-in DK.