I have this same issue... **** Solenoid E P0770 .. I’m guessing it’s the Lead Frame, the nodules that connect to the solenoids get dirty, there is a new film that they put on it.. just as a matter of preventative measures everyone should replace that along with the fluid filters and all the seals.. also when they flush , transmission MUST be hot or the thermal release valve will be closed and you,l be replacing 14 quarts of fluid but only through the cooler and valves and not the transmission itself.. it’s a big deal.. it must be hot, but if you replace the lead frame, then you’ll be good... because that valve will come out ...... if you have this issue and go to the dealer, don’t let them get away with,, we will test all this crap first BS tell them that you want all of it replaced, the lead frame with the new nodule strip, all the seals,, maybe even price out the 7 solenoids and just swap them. Yea. $1500 but you’ll have a basically brand new transmission