Tercüme - Türkçe-Almanca - Lütfen kapıyı kapatın

"Können sie bitte die tür schließen?" is a question, but the source text is definitely an order.

Yes,it's actually an order but my translation is Can you close the door in a polite way

yes, but it's often the case, that people don't really obey, when they only hear a polite question instead of a real command. That's psychology and therefore I guess we should keep it as it now is.