I did it to myself: throwing P0AA6

The HV array was swapped from another vehicle and used for a week-ish before being pulled again to do a re-build with 6 modules. Before I was going to pull it it started throwing the code (P0AA6), and forcing neutral on restart. I noticed when I pulled it that the main (negative) relay was burnt around the nut, I hadn't correctly (like at all) tightened that nut and I had arcing residue.

Since this was a different code from the voltage differential trigger one that I could clear with Dr. Prius app and keep truckin', I figured that I would order a used relay while everything was out and I did, and replaced that negative one.

Today the array went back in, but the code remains. I was able to do a Dr. Prius app charge/discharge test successfully. It triggers pretty consistently, I can clear it and restart to get into drive. I drove it for about 2 miles, it felt like gas only but I did clear the code as I was driving, I don't know if that disables the inverter for safety.

Next step, I ordered two more used main relays and that white resistor that goes to the negative main relay. By next Wednesday I'll see if the trouble ends there. If not, I have a standing appt that Friday to get the 526/??? codes read at a Toyota dealership, I'm hoping to avoid that. $150 just to read them, nuts.

So, my questions to you are:
1. Is this an existing issue, has anyone else done this kind of self sabotage?
2. Did I kill my inverter somehow? Fluid is gurgling, it seems to work until the code triggers.
3. Any ideas on things I can do/test while I wait for parts?

 

Hi all,

I will catch up with where I'm at, and I'll address the questions that SFO posed. Thanks for those!

I'm only using the Dr. Prius app with a bluetooth OBD reader. I assumed the 526 sub inf, because I read the P0AA6 always throws that, I didn't see it on Dr. Prius. It throws the code consistently within 90 seconds, as it should for low resistance. And then with every restart, I clear what Dr. Prius can't see, but can still clear. Then another restart and it runs fine. The mechanic at the dealership was kind enough to provide the second inf (614) for free and we discussed my non tightened nut arcing issue. He believed, and could see where I burned the ring terminal, that I shorted the HV cable that runs to the inverter. It's the frame wire in the inf 614 area. That's the $680 "on sale" new cable from Tokyo that I will find locally in a car salvage near me for $80. And just to quickly address SFO's battery troubleshooting section: the 614 removes that concern, but also the code was throwing before the rebuild (but after my piss poor temporary install of it that caused the arcing issue,) and the battery's been examined multiple times anyway due to a failing hope that it WAS the issue. This now is a whole new thing.

I have two issues now, maybe three:

1. How to use a megger. I'll have a Vici VC60B+ with 6 aa's tomorrow. The first cable I found near me is open in the rear, batteries' already out. I'll pull the wipers and cowling, open the inverter, unscrew the terminals and the bracket, release the cable from all that and somehow hook up a megger. I didn't know that was a word until last week. I found a post here, that I need to find again, that addressed testing and replacing this cable. I could use some resources for understanding if the HV aspect of the cable changes testing, if the megger I ordered is sufficient to the task, or anything else. I'm aware of avoiding the clips when firing the test. I am wondering about using my longer alligator clip cables I bought for the T180 discharger/charger unit, I'll check the gauge of the megger cables and see.

Biggest issue : I don't know what I'm doing exactly procedurally. I watched a uni tutorial on safety and self testing for the megger, and there's a lot of HVAC stuff that is helpful-ish, but I'm going in with theory right now and that's worrisome. Only really, that I'll waste my time and $80.

2. The salvage yard is going to somehow give me good access to the underneath, but I also am not sure what I'm in for there. The OP in the above-mentioned post's advice was to basically spend some time, examine it, and it will become clear. I think he said difficult and clear.
That's cool, but if you have fun exploding pictures that you might share, or ideas on procedure that can be done quickly, safely, and possibly with awesome salvage yard tools (I have real tools but they offered,) or links to other posts on the issue(s) I'd appreciate it!

3. This cable fault didn't seem to be a progressive issue. Heh. Two days ago I drove, farther than usual, 15 miles of city, 10 of country, then i get a P300 OPOA85 - still not clear on the o's and zero's - and then I clear it five more times within a minute. My destination was near, I parked it for about an hour. I took a straight, clear route home, and only had to clear it about 6 times in 25 miles, 3 of those were within a half mile of home. Now I'm really annoyed. Did I make it worse by driving to my sister's bonfire?

Yesterday and today I drove it locally, 3 or 4 miles total, it only threw the low resistance code at start, as usual. I want to believe this is a ghost thing, that will magically disappear when I install a good cable. If not, is it related or a whole new fun thing? No misfiring, no problems maintaining speed. I'll stop driving it for a bit.

Now I imagine catastrophe under the hood, I'll look in the morning.

Thanks!

Scott