My 2nd P0AA6-526 Hybrid Battery System Isolation Fault on Original Battery

Thx for posting diagram. My P0AA6-526 turned out to be fan motor. It evened affected abs codes...

 

Hey there can you explain a bit more on that situation? I am experiencing the same issue and I pulled a P0AA6-526 code and looking to get answers

 

It won't have been the fan motor; the P0AA6 code is exclusively about isolation failures in the high-voltage system, and there are not any fan motors in the Prius than run on anything but 12 volts. But it happens surprisingly often that someone can have a code for one reason and have the problem go away, or seem to go away, while they're looking at something else, and then conclusions get drawn.

There's a useful graphic posted up in #1 above, but the color highlighting is wrong. Here's the fixed version:



The INF code 526 that you have is just the one that sets first, and does not tell you any specific area of the car where the isolation fault should be found. For that, you need a 611, 612, 613, or 614 code to come up.

The specific code will come up on your next power-up of the car, as long as you do not clear the P0AA6-526. Powering up, the car will say to itself "hmm, I see a P0AA6-526 from last time, I will watch for the fault while powering up this time, and set the specific code for the area where the fault is."

If you do clear the P0AA6-526, it'll just come back the next time the fault is detected, and you'll be in a useless cycle of clearing and getting P0AA6-526 and never getting a more specific code.

 

Gotcha thanks for the quick response! Didn’t expect within a day. I’m using the tech stream software on my laptop so I’ll need to let the car give me the error again as I cleared it before I seen your message, I’ll report back my results when I have them! Let’s hope I can get the sub code

 

Try turning the car ready then off multiple times.

Posted via the PriusChat mobile app.

 

Ok everyone, I checked the codes and got the subcode, the subcode is 612, so the HV battery area. What can I do next to find why the error is triggering

Edit
I was looking through another thread, am I able to follow these steps in this link to find the issue, where can I order a part for it if I need to? https://attachments.priuschat.com/attachment-files/2018/04/145252_2006_Prius_RM_-_P0AA6.pdf

 

Following up on this post as it helped me.
In the post above the original post, I did the voltage test to see if my battery case would hold a voltage. It kept jumping around and then I went ahead and started to disassemble the HV battery.
I ordered a insulation tester off amazon and tested my modules (I used this one from Amazon

)
I used this video to guide me to find the correct module that was leaking or had leaked.

I tested all modules using the video above and found the pair that was incorrect I knew it was incorrect as the insulation tester that I used was giving me a negative value, and I knew it needed to above 1ohm at least.
Here is 2 pictures I took of the HV battery

() [direct link in case the img link doesn't work]
As you can see from the image the first thing I noticed is that it was pretty bad compared to when I last took apart the battery.
I removed the bus bars and did the test on each module, and the one that failed was the one that had the most staining from the leak,none of the others failed. I had ordered 3 replacement modules on eBay and threw the one in that needed to be changed. And to clean up the leak area, I took vinegar and water and sprayed a toothbrush with it, and scrubbed the areas that were effected by the leak. Now I also did baking soda and a little water and scrubbed too but not sure if that helped. I followed this link here on Youtube to guide me on taking out the HV battery and everything else. (

)
To note though, I did not have the money nor the experience to do the load balancing thing lots of people talk about and that may come and bite me in the butt in the future. But the car already has 300,000 miles on it. I am not too concerned about the hybrid battery as much as everything else in the car so I thought it was worth it to just chuck in a module and hope for the best.
As of a couple of weeks, the car is driving fine. It threw up an error code P3000 twice, and I cleared it and it has not been back since (Hopefully). It was a lot of work to take out the battery and flip it over constantly so have a helper be able to assist you there. I had my dad help out and he was a great help.
We did not use manual tools as good lord that would have taken forever, invest in a toolset and a trusted brand and let the drill do it's job.
Keep everything organized and make sure all the nuts and bolts are organized, I had a few missing and I still have no idea where they went.


oh, and we lost a 10mm ratchet somewhere during this rebuild. People do say those 10s go missing and I guess that's true!