[78F350]

I have a water damaged alarm/immobilizer (under the seat) box. I plan to get an entire set of DME, key, and immobilizer to replace it.
BUT...
I can't help from wondering if I could just de-solder the processor chip from my old water damaged board and put it onto a working board and use it with my current DME and transponder key.
Are there any engineers out there who know how this stuff works and can explain it to me? ...