how many parts should I change after ECU change?
 

My car is a 2004 AT (with DSC and immobilizer)
Recently I got an ECU ( one guy crashed his car and sold the remaining) from another 04 AT. I sent it to Knightsports for speed, rev limiter removal and fan control swap. After its return, I found my car wont start after ECU change. Is there anyone knowing how to do ?

It will not start. Because the ECU need to match the BCM like key and lock. It won't start if the data does not match.

Dunno what I can tell you what to do. I was talking to Nakamura san from Japan last Saturday and told him that I was so happy with his tune.

You probably need to send them your original ECU, Copy everything over to the used one, then you re-program it.

You cannot reprogram since you don't have the software to do it.

I think send both and see if KnightSports can do something about it.

the 2nd ecu you bought also with DSC and immobilizer?

i am wondering if both ecu with 4AT DSC and immobilizer, would the swap be possible?

one of my mates is selling his 03AT with DSC and immobilizer, his ecu already flashed by re-amemiya. i am thinking to swap with his ecu, but my ride is 04AT with DSC and immobilizer. but i am worried that the cars wont start like what taka said. is our car milleage follow the ecu?

please advice, thanks.

The swap is possible. My second ECU(the original one of my car) worked well
If you want to send another ECU to swap, be sure collect the following parts from the source car: the black box below the ECU, the dash panel, the ring of key entery, the key.
If you collect them, the dealer may reset the immobilizer and your car can run

Yeah but the thing is that dealership in USA cant do it for you.

You can send it to headquaters or their R&D center.