G'day brains trust,
I have a ACV36R (series5) 2.4, that stripped the 3 rear head bolts. I have done a complete Timesert thread repair to the block and rebuilt the head while I was at it... What a nightmare that was, anyhow, all completed..
When I went to fire it back up, she just cranked without firing. Did all the usual checks and found the security light still flashing on the dashboard.. Cool, checked the fuses and relays, all good. Did all the key re-programming methods, no dice. Did a lot of wire tracing, all good.

Figured the ECU had lost the key codes or was just generally dead, so purchased an ECU with matching key, steering lock and reader, door lock and boot ( Trunk) lock. I saw this working in the donor car, which was an exact match to mine. ECU ID code are exactly the same...... Sweet.

Installed the ECU and connected the new ignition barrel to test.

NO GO!!!

I did notice that the bottom row of telltale lamps of the instrument cluster glowed dimly when the key was inserted using the original ECU, which I thought might be a bad earth somewhere, so I added earth straps to strategic locations. With no joy. However this does not occur with the new ECU.......

I am completely stumped as to WTF is causing both ECUs and keys to not turn off the security lamp, it just continues to flash...
When I lock or unlock the doors with the key, the hazards flash once for lock and twice when unlocking, though the security lamp continues to flash....
I read that there is possibly an Immobilizer unit under the dash near the glove box, but I can't find anything. Also where is the location of the Body control module and how to best access it??

​​​​​​​Any and all help Greatly appreciated.
Cheers!!!!!