mos12osut

Hello all, I got a question. Recently I been having trouble with my keys opening my car(2004 e60 m54 engine), I have the diamond shape key not the newer version. When locking or unlocking I damn near have to stand next to the car just to activate. I saw a write up on here about replacing something called a "diversity amplifier" to better fm reception,& remote key use. But I'm not having a problem with fm reception, just the keys. So I ask should replace the key or that part, I only that key besides the purple valet key the stealership gave me years ago.