Yes security light goes out, we don't believe it to be an immobiliser as the start starts and can give it a few revs before it cuts out.
Once it cuts out then there's no sparks.
Does you or anyone else know if I buy a replacement ECU module, does it need to be reprogrammed?
The conclusion so far is its some sort of signal issue somewhere.
My mechanic has given up on it and my only option is now to book it in at main Lexus dealers....