first off, you cannot install notheros or any other unpatched firmware in factory service mode. it will fail on bluray installation process.
second, this lv2diag.self does nothing at all. it is useless with a real rsod, this i can asure you.
the only thing that helps is the pkg made from the users from downgrade irc channel. but if it is a hardware error, it will return.
i would try to run the pkg, and then do a factory service mode install with another firmware that is bluray bypass patched (rogero's for example). but the pkg will only work on that notheros. after this you can install any other firmware. though, as i said, it maybe return as of hardware=nor corruption.
a real fix would be replacing the complete nor chip
sony has put this error in lv0 if a nor corruption is assumed. i think if somebody can patch this error routine, it will also work without problems. but here i am assuming