After HV battery rebuild, no codes, will not go into D

2005 prius 140k. Threw a red triangle, I determined bank 5 was low. I got a used good blade, charged it on the bench to match voltage of the other blades, and installed. I cleared codes and all was well.

I drove the car down the road while monitoring the HV battery in Dr Prius. About a mile away, there was a klunk, and the Red Triangle came back. The car was very sluggish and wouldn't go over 35. The energy display showed that there was no interaction with the battery at all- it was strictly running off the engine.

I read the codes and I had a P0AA4 - saying a contactor was stuck closed. I tried tapping them with a nylon hammer to no avail. I pulled the HV fuse and disconnected output wires from the contactors and checked continuity on the contactor terminals. They were both open as they should be. I put it back together and put the cover on over the contactors to make sure the metal rings around the output cables were firmly grounded, in case that matters.

I pulled the 12v battery neg terminal to let everything clear. I just had the HV battery sitting there not bolted down for my initial test. I bolted it down in a couple places, in case the case ground was important.

After a long wait, I reconnected the 12v battery. Using Dr Prius, I cleared all codes. The triangle went away, and no battery or engine codes are reported, either in torque or dr prius.

BUT- it will not go into D or R. Just P and N. And I have the following lights: brake, CEL, Maint Req, ((!)), ABS, car skidding

At one point, I did try it with the HV fuse out (by accident). I got battery codes P0AA4, P0A0D, P0AA1

I also checked fuses and they all seem good. The 12v battery reads 12.2v. That strikes me as a bit on the low side. I'll hang a charger on it tonight.

I did replace a battery blade a few months ago, and I recall I had some shenanigans kinda like this before it started working, but it eventually did.

 

Yes- it is back correctly, and I verified that I get something like 235v at the output of the battery before the contactors.

 

Ok- I was able to get out of this weird state by "rebooting" - power off, hold start button for 45 seconds, foot on brake & start button. Doing this brought it back to normal...
BUT on a test drive, it very quickly threw a P0A7A (Generator Inverter Performance).
I reset this, drove further, and I quickly get P0A94. This happens over and over.
I took out all 3 relays and bench tested- all good.
Now, I sometimes get a P0AA4 which is negative contactor circuit problem. I guess the next test is to see if I get 12v on the contactor coils when the car is on.
I need to get techstream happening- I'm doing all this with torque and dr prius and a blueooth ODBII and it is a real PITA to get it to connect reliably.

 

do not know how old the battery is. It was in the car when we got it 9 mo ago. It is a nice Ac Delco AGM, so it had been replaced at some point by prev owner.
I hung a charger on it last night and this morning it showed 12.8, so I think that is OK.
Right now I'm trying to get an old XP or win 7 laptop running so I can easily set up techstream. I have a VCI cable.