Rep Power: 0

So Honda dealer told me that I'm getting a P0971 transmission code, P0971 Pressure Control Solenoid C Control Circuit High. Honda says I need a new transmission, or that changing the valve body could potentially work (they said that's not a guarantee). The drive light blinks green when the car is on, and the car will very clunk-ily go into gear and inch forward, but it's not drivable for sure. It will also repeatedly rev up to around 4k and then back down 2k while in drive.

Does anyone have experience with this? Local shop said that they could try to just replace the pressure solenoid, but that they don't know if that would do anything. Can't find any DIYs on that, and I have no idea if that's even something I could attempt myself. Youtube/Google search shows control switch A and B replacement walkthroughs, but not solenoid C.

Thank you in advance.