Transponder ECU problem

[SC V6]

I was curious... the ECU is what says what code it wants correct? Like to let the car run and so on, and the ECU tells the Theft Deterent Device to flash the light right? so the code for the ignition and the ECU need to match correct??

also does every ECU have a different code, like if you were to swap an ECU you would need to get the code from the dealership? do they have these on record???
thanks

[mhood]

it is a little more complicated than that---what exactly are you asking or wanting?