The 2zr-fe engine swap guide

[CTScott]

Originally Posted by ArmstrongRacing

OR.....

Someone could leave all of the immobilizer parts intact, tow the car to the dealership, pay the techs $200 to try their best.....and possibly get answers for the whole community. If they fail, no big deal and you disconnect the ECU.

There is a limited amount that Toyota techs can do. If you have the master key for the original immobilized ECM you can add new keys (so you could add a Yaris key to the XD ECM, if you got the XD with its original master key). Without the master key there is nothing Toyota can do (except replace the ECM and keys).

Beyond the dealership, it is possible to clear the existing transponder key data from the ECM (so that you can add new keys, as if the ECM is brand new), but that requires opening the ECM an desoldering and reflashing the EEPROM that stores the data.