2009 Prius - Error Codes Galore

Original owner of a 2009 Gen II, Have about 190k miles on it. Car has ran wonderfully, minimal maintenance during its lifetime. I commute about an hour each way. Recently, while going down a windy, steep decline, the warning light with the ! came on the dash and the screen displayed "Problem." It went away after a quick second. I figured it may be low on oil, because I was due for an oil change that weekend and the last few times the place said the oil was pretty low. I've been trying to cut down on the mileage between changes.

That weekend I went to get the oil changed. On my way back, all warning lights displayed on the dash and the engine shut off. The car allowed me to go about 5 mph on electric while I found a place to pull off. I turned the car off and on again, the motor would turn over, but once I tried to drive it would shut off after a few seconds. I ended up towing back to my house.

I ordered a Mini VCI cable and Techstream (that is a whole other story trying to get the program up and running, but I finally did it).

I noticed that the engine wouldn't turn on anymore and the hybrid batteries were only displaying 1 bar. I do recall the car acting weird whenever the 12v battery would go bad, so I went ahead and changed it it today. I also checked the oil and noticed it had about a half quart too much, so I drained it down to where it is supposed to be. I read somewhere on here earlier that too much oil can cause problems.Now the engine turns on and it charges the hybrid battery up to about 3 bars before shutting off. Some of my error lights have disappeared. However, I still have the following codes per Techstream:

P3190 - Poor Engine Power
P0A0F - Engine Failed to Start
P3000 - Battery Control System
P0A80 - Replace Hybrid Battery Pack
C1241 - Low Battery Positive Voltage or Abnormally High Battery Positive Voltage

I've been expecting the hybrid battery to fail at some point. From the screen below, it appears that block V14 is lower than the rest.


I am pretty sure I can handle the battery, based on other posts here and some youtube videos. My concern is that I do this, and it doesn't resolve the other error codes. How can I be sure they are all related?

Is it possible to dive into those other error codes through Techstream and get specifics?

 

Oil changed every 5k-8k miles with synthetic
New tires when needed
Brakes actually just serviced for first time in December
Replaced the inverter pump a year ago
Replaced the driver's side headlight module twice
Replaced the MFD last year (screen went bad)
12v battery replaced maybe 3-4 times

Car has just been a little commuter workhorse for the last 5 years or so, and just sits on the weekends. Bought another used Prius last week, so I can take my time on fixing this one.