Prius turns on immediate upon connecting 12v

Have a 2005 prius that has had a current draw so I've been disconnecting the 12v, now when I go out to use the car and I connect the battery, even without the key fob in the ignition all the dash lights come on, hv battery fan starts, hear it click, I get the triangle and beep. I was getting a hv battery ecu communication error code thru techstream. I did a search and came up with a thread on here that (gen 1 tho) said the tank pressure sensor shorted and was messing up the ecu. I looked at the wiring diagrams and maybe that's what's happening to me? I checked the IM1 connector and there's mouse piss on it and the pins have that blue tarnish. Here's a diagram I pieced together to help myself out. I'd pull the connector at the tank for the pressure sensor but I can't get to it. I have a lift but the car doesn't move with that stupid parking lock and I can't get it into the garage with a lift. I can't tow it with my truck either. Seems easiest just to cut that vcc line going from pin 9 IM1 or release the terminal from the connector if I can (save me from soldering it later). Thoughts?

that other thread No start due to P3106, ECM -> HV ECU communication failure? | PriusChat

 

oops I put this in the wrong forum.

 

That was it, runs good now. Cutting the positive power to the tank pressure sensor alleviated the issue. Not very good design if a flawed sensor takes down the electrical system.

 

Driving it around for a while, twice it did something very strange. Engine raced and I actually had to step on the brake because the car started accelerating hard by itself. I pulled over, turned off the car, let it sit for a couple minutes, then it worked fine again. I'm thinking there's something going on also or maybe even the only cause at connector J14 which supplies the ECU and the throttle positions sensor. Or like you mention something else fed by that bus. Maybe a bad TPS or the "w-5 water valve" I've updated the above drawing to include this new development

prius chat shrinks the image so here's the original https://i.postimg.cc/KmSnbgm0/hv-com-err-1.png

 

Its tough because it happens maybe once maybe in a few hours of driving and my laptop doesn't have enough battery power to do more than a few minutes of logging (with how long it takes to get everything set up)