This seems the typical main dealer service.
If they guess at swapping a few really expensive parts and it doesn't work,they give up and it's sod the owner!
This is not just Lexus as other people have posted with similar treatment
Whatever happened to motor engineers?
I think maufacturers have too many models and mechanics never get fully familiar with them all.
If the answer doesn't come up on the computer they are lost.
We don't need a mass of computers, apart from engine management, most things will work with
just a simple relay for switching things on and off, opening windows etc.
Now it all has to go through a £500 computer system, linked to three more with 20 IC's on each do the same thing.
Many a good car is now scrapped because some unnessary electronic gadget costs more than the car is worth,
or so called main dealers cannot fix them
Who said I was a Luddite!.....wait and see!