i just wanted to share my experience with you guys because i got so much useful info from here when i conquered this problem.
i have an 01 with about 185k miles now, at about 160k i had the same p0770 and whirring like a power steering pump coming from the trans and i couldn't shift out of second gear. did a bunch of research, seems that the aluminum planetary breaks up because the car is too big and heavy for that little camry transmission. oh well. the car was given to me as a hand-me-down with a bunch of miles so i wasn't too upset about it. but i wanted the car to work. i did the fluid change/sensor swap which didn't really help. the car still bucked when shifting, etc. but there was quite a bit of debris in the trans pan when i dropped it... so i went one more step, and addressed the solenoid that was giving me the code in the computer. dropped the valve body, disassembled it, cleaned thoroughly inside and out and reassembled it. new fluid, and voila. truck works again. over 20k miles tested and true. truck has kicked every morning on the first 2nd to 3rd up shift now for about 5k miles. after that it is fine... not sure how long this will last, but i will certainly do it again if need be.
my guess is aluminum chunks from the planetary are getting stuck in the labyrinth that is the valve body, keeping the solenoids from doing their job. i bench tested the solenoids and they all seemed up to par.
there are companies that rebuild and strengthen valve bodies online, not to mention local trans shops as well. also online there is a lot of data online with fiches and what not to help. spent less than $200 bucks to have a working car again. changed the fluid and filter again after about 5k miles to make sure the fluid was mostly fresh.
if you wouldn't change a valve cover gasket or something like that, this job may be a little much for you, but i had no experience with automatic transmissions at all before this. a nice clean bench and space to work and it only took me like a weekend after my parts were in.
if i can help anyone save a few grand i'd be glad! i think i still have the .pdf files i used as info for the u140 in this thing. i can probably upload them somewhere all together to cut down on research time if anyone is interested.
if for whatever reason this happens again i will certainly take pictures or the process, and if that fails you will probably see a later model highlander/camry trans swap.
anyways, thanks guys because you guys made this thing work again! hopefully i can give back a little.