Death Triangle and Battery Issues

Upon turning on my car and driving a few feet I had the Red Triangle of Death, Yellow VSC, Yellow (!) Indicator, and check engine light and I'm trying to figure out where I should start working on the issue.

The Codes were as Follows:
P3000 (subcode 123)
C0200
C1241
C1300
C1310
C1259

A little history:
About 3 months ago I had an issue with the hybrid battery and replaced a battery cell which stopped all issues. About 2 weeks ago I replaced the coolant inverter pump and until today there has been no errors, CELs, or any negative performance.
This is a Gen II, 2007 prius with almost 200k miles.

Unfortunately I had plans that I could not reschedule and made the drive to the location and drove back. I had serious battery drain and it was almost always at 1 bar of battery, sometime reaching up to 2 bars. There is also the sound of a fan coming from the back seat, which I assume is the HV Battery fan, but it is on regardless of if I have air conditioning or not. A/C is working fine. When I returned home the battery charged almost up to full bars, but when I came to a stop the battery drained in about 10 seconds leaving me with very low power to keep moving. After that whenever I slowed down the teal arrows showing a recharge of the battery were gone and the battery seemed to refuse to recharge.

Steps taken so far:
I topped off my engine coolant in the front reservoir as it seemed a little low, but I didn't add much before it was full. The other reservoir near the engine was just about full and taking off the other cap showed coolant filled to the top.

I tested the 12v battery with my voltameter which came back reading 12.7.

Is there any other steps I can take to diagnose this issue? It's curious that I don't have more codes related to the HV Battery and just the p3000. Those other codes seem to be general errors in relation to the Skid Control ECU.

Any idea where to keep going?

 

Replaced a single bad module. P0a80 was the error code back then.

 

12.7 volts on the 12 volt battery seems about right to me. I'll try and do some logging with Techstream tomorrow but I don't know what I'd be looking for on there.

 

Started with the last suggestion first as based on your description of the motion I knew exactly what piece you were talking about. Snug as a bug. Just to be sure, I removed it and fully re-inserted it. I have not checked the ends of the connections because I want to rule out some more things before I start the hour long process to remove the trim to access the rest of the battery.

As far as the first suggestion, Yes, I have the MiniVCI but I'm not sure where to find the specific DTC. I've got a bunch of pages from TechStream's current Freeze Frame Data for the Battery Control System. Could it be on there? I'll level with you, I have no idea what I'm looking at when I look at that FFD.

 

I've also been googling around and scrolling through the information I have on TechSteam, I think I might have found the specific DTC for the C1300 error which reads 1062.

According to https://techinfo.toyota.com/t3Portal/document/rm/RM07X0U/xhtml/RM000001S22002X.html?sisuffix=ff&locale=en&siid=1462406944767 (This is for a 2008, I cannot find something like this for a 2007 and I will make a possibly wrong assumption that 07 and 08 are close enough.) This leads to a step where it asks me if the voltage is over 8v in all fields... however some of the voltage fields it asks for are reading less than 8v. (+B1 and +B2 for example, are both reading 6.74) to which this manual says to inspect the Auxillary Battery and Charging system.

I've already inspected the 12v battery and it seems to be functioning normally. As far as inspecting and testing the charging system I have no clue how to do that.

...assuming that detail code is correct
...assuming 2008 and 2007 are the same in this regard
...assuming someone didn't swap out my battery with a chocolate after the test.

OH! And Keith, I double-checked the value on techstream for the battery and it was reading 13.8. I guess when I ran it the juice was flowing correctly. So based on this I'll say it probably isn't the 12v.