07 Mazdaspeed3 won't crank

I have an 07 Mazdaspeed3 and while I was driving it just turned off and now it won't turn back on anymore. It keeps flashing the anti theft light on the dash. Can't even connect to odb2 or anything. I have a simple Mazda3 and I tried using that cars ECU on the Mazdaspeed3 and it wont crank at all. I did it the other way around where I used the Mazdaspeed3 ECU in the regular Mazda3 and it cranks but won't turn on. Do you think this is an issue with the ECU?

 

The ECUs are not interchangeable at all and you should be very happy that neither car started as it would have been potentially very bad for the motor

You unfortunately triggered the anti theft immobilizer the only way to remedy is a tow to the dealer