Reprograming Key Via MultiEcuScan

[dagdromer]

I wonder if there is some limitation in the system, that remembers the key no matter how long ago it was programmed but if programmed out it switched the key to being inactive in the memory of the immobiliser and then can’t be switched back a bit like the mileage can be increased via MES but not decreased. Maybe someone with the right software and know how could program it back in again? For 99.999% of the time reprogramming an old key probably isn’t a concern

I know for the fiat panda that the keys are stored in the BCU (body control unit) EEPROM. There is a block where the active keys are stored with several parameters and there is a block for locked keys. If an active key is not present when relearning all the keys into the BCU it is moved to the blocked area. I believe it can store up to 8 keys there. I've been able to unblock a key by manually editing the EEPROM dump and writing it back. I only needed too do this once so if this was the correct way or just pure luck, no idea.