Prius battery module bad or no?

Don't worry about the sparks when disconnecting the 12v.

P0AA6 is not great.
Just to be sure....
You put the car in "Key On" position. (NOT Ready on. This is important.)
and the code comes back in under a minute.

If so, then, as the video says, the voltage leak is in the HV Battery.

You are going to get back into the HV battery and diligently hunt down the problem.
This will take time and effort.
Check all wiring connections.
Check all grounds.
Check every one of the sensors.
You can probe them carefully with a small wooden dowel.
Even a small break or leak can be problematic.

It is important you follow the steps in the video exactly. Else you will be looking for the leak in the wrong component.

 

You've already been inside your battery, so I'd say open everything up and let it dry out. Hopefully you can get the car inside and get some heat on it. I'll bet you find condensation inside the battery. Good luck and don't get killed as your user name would imply.

 

OK, you've said your 12 V is good several times. Please report the no load, load, and ready voltage. See Weird stuff happening? MPGs dropping? Test The Battery | PriusChat

Your fault code says there is a leakage current between the HV circuit and the car's chassis. This is like a ground fault error. The leakage path can be breakdown of the electric motor insulation, the air conditioner's motor, the inverter, wirring, or the HV battery. Your Luscious Garage video technique suggests the ground fault is in the battery. This usually means a battery module has a hairline crack and has weeped a little electrolyte. You indicated you had a water leak so there was a chance the traction battery was just wet.

Please explain your reversal of the battery contact stripping.

 

Wow! You direct shorted several blocks. I'll bet you did see sparks.

 

WTD? Thank goodness you are okay, WOW

 

I would try cleaning and putting back first. This might be cell leakage, but you had a water leak so it could be that. Under constant voltage and high humidity metals can electromigrate. This could account for the stain and the corrosion. You've probably read the low success rate with module replacement, so go that route only if you have to.

 

Glad to hear from you again, sorry to hear the latest.

Let's summarize. Let me know if I miss something. Your mechanic told you your traction battery was bad. You pulled it out and measured each module. It was then discovered that the 12 V battery was dead, so you replaced that. Next you had a P0AA6 High Voltage Isolation Fault. We also discovered you had water intrusion into the battery area. You inadvertently shorted several blocks, but everything measured OK. You did find a potential leaking module that could explain the isolation code. Now you have a P0AA3 Hybrid Battery Negative Contactor Circuit.

This is the only mention of P0AA3 on priuschat. You're breaking new ground here. Before I did anything I would disconnect the 12 V to clear all codes. While at it check the 12 V, it may have gone flat in the month you were away. If the code comes back check the hv battery to see if you have a lose wire to the negative contactor. You've been in there so many times you could have bumped something. And as always be careful. Good luck.

 

I'd just like to point out a misunderstanding that you and others seem to have fallen into in regards to the above statement.

Wiring in parallel (but not charging in parallel as Steve (S Keith) mentions) is not balancing. It is voltage equalisation. As Steve also mentions, due to NiMH chemistry it is of little value.

Balancing really speaks to bringing each cell, within a module (there are 6 cells in a Toyota module), to a state of charge such that each cell is within a close tolerance relative to each other (in respect to voltage, amperage and capacity), so that they all contribute equally to the module's ability to store and deliver power. The way in which this is done is to charge the module very gently so that the lowest performing cell(s), within that module, are brought up into the range of the better performing cells. This means that the good cells are gently overcharged, and this over charging is dissipated as heat. The good cells can tolerate this as long as the heat is not too great and hence why cells are charged at a relatively low current. I believe this process is called top balancing.

There is a process call bottom balancing, which I don't understand enough at this point to expound on, so will leave that for someone more knowledgeable to explain the process, cautions and benefits of bottom balancing.

More knowledgable people, please feel free to correct anything I've got wrong.

I hope this helps.

 

Glad to hear it. If possible conduct the discharge test in my signature. If you have techstream, record and upload the file.

Getting a baseline is important. The discharge test is something you can do periodically to assess deterioration and determine if/when additional grid charging/discharge is needed.