Hi all. I recently got my flipper and its been going great.
I mapped my car key last night and it worked several times. Tried it again today and I get nothing. I recaptured and sent the signal several times with no result. Is this due to a bad emitter? I cant wrap my head around this.
I am in the US so im on the 315 and AM650.
Again, nothing changed in the meantime. I downloaded some bad USBs off github could that do something?
Just bummed and wondering
We can’t help you without more information. Car keys are mostly rolling code so I’m surprised it worked twice. Things like pictures of the fob and FCC id will help.
My key does not have an FCC if on it and there are no markings other than the mustang logo. It is a 2012 mustang. I ripped the key open and there is no info on the chip either. And it worked 3 times now that I think back on it. is there some other way I can test the emitter to determine that it is my car?
Pictures of the chip inside would also help. The FCC id was probably there at some point if you are in the US. It could have been on a sticker that is long gone.
the only numbers on the chip are 1138 cpcp g3 94v-0 near the bottom and a 3411 sticker higher up the chip.
I found a youtube comment that said you may be able to do it only once in a row if you copy a long portion of the signal somewhere your car cant read the signal then replay it to your car. Maybe thats what I did. ill try again
Let me get the details correct. You said “mapped” your key. Are you saying you captured the key just after adding it to the system?
I mean I saved a different file for unlock, lock, and trunk so I had a virtual “complete” key saved to my flipper
And it didnt work 
Im very surprised it worked the first few times yesterday now. I though mapping car keys was one of the best features of the flipper and now I find out its not one of them
Short answer with rolling codes is that no code works twice. Here is the longer answer.
So most of the videos I saw online of people unlocking modern cars with the flipper were faked then. Shame. When I try to recreate it though it still doesnt work. Is that normal? Also I read that I can de-sync my key by accident and lose its functionality. Should I be worried about this?
Most of the videos are probably legitimate but without context. You can copy the signal to the Flipper if you are out of range of the car. Then the Flipper can replay the code to the car 1 time if the remote the code was copied from hasn’t been heard by the car. I recommend not playing with rolling codes too much if you don’t fully understand them. In most cases there is a process to synchronize the remote again.