Hello,
I have a 110 hp AHF Golf 4 and I want to get a spare ECU to fool around with. My ECU's part number is 038 906 012 BT. From what I know the last letters don't matter (or do they?). I have found an ECU from Audi A4 90 hp with part number 038 906 012 AF. My car is immo 2 and I know about the VCDS procedure. The question is can I just plug it in and copy my map to the new ECU or do I need to get an ECU from a Golf with the same engine?

Thanks in advance.