I have the same problem with my 2007 lexus is220d se, although it is intermittent and very annoying, no warning just goes of when it feels like it ,could be parked up or turning
no consistency at all. I stop[ the car turn it off and on a couple of times, sometimes use the fob to lock and unlock the car ,sometimes it comes back quicker that way,
then when it does it might be fine for 80 miles of various driving ,got the code read it came back with motion rotation sensor??? I don't know ? but thought if a sensor failed it had failed? the steering comes back fine for a few days to a week ad various mileage? im new to lexus come from audi tdi so these are new to me do a lot of my own repairs and maintainace,so wondered has anyone else come across this problem before, would be very grateful for any feedback...tthanks