Removed from a 2002 VW Golf MK4. Good working order with no related fault codes and no dash lights.

CANNOT STRESS THIS ENOUGH THIS WILL FIT VW GOLF MK4 AND BORA ONLY!!

NO, it won't fit your Passat B5

NO, it won't fit your Seat Leon

Part number may be the same  but it won't work on other models due to internal software difference.