Hi Kennythewelder, I had a certified Lexus Mech ( very highly qualified, trusted friend) do a tune up and specifically address the problem detailed Dec 17, above. He cleaned the, for lack of a better name, 'firewall plug' between eng and cab saying that those sometime corrode and can cause the problem. He said the other possible fix would be to change the ECM, 12 hour labor to get to it, and no guarantee it will fix it, I did not for that $1500 option. In the process he asked me if I had a spare key. I said I did, a Grey fobbbed one ( the normal every day key is 'black' fobbed, saying that if the problem occurred again, try the grey spare. So after 80 start/run cycles she failed, I immediately put in the spare grey, and presto stared right up, normal. And as stated above, when it fails, you try a restart ( with the black key) as many times as you wish with a 'no start' result. But with the 'spare key' (grey) procedure, starts right up. So why would you suppose that to be? Thanks very much for your time. PS I told him about the' live date code', did not seem to boil that into the 'fix receipe'.