After reading all post I can find on this code, and checked O2 sensors and cooling system & components took the car to the local Toyota dealership (they have always been top notch in the past) & the nearest Lexus dealership is a little over an hour away to see if they could pinpoint the problem for me, What they are telling me is it looks like the ECM, Could this be the problem?
Car has 180K on the clock, and runs perfect.
Being in Calif. the car just passed the emissions test about a month ago so all was good.
Any help would be appreciated,

Thanks,
Bill

 

I think it's the coolant sensor