P0AA6, detail 526, and 612

I would look at the modules end terminals for leaks. And usually if you let the car sit for a week, the leaking module will drop in voltage.

 

Welcome to Prius Chat .

Some questions:

• What torque are you using when you swap modules?
• Are you charging the pack when you swap?
• What color is the spillage?
• Do you have access to pH strips?
• What do the bus bars look like?

Good luck and keep us posted .

 

This makes no sense to me.... "looks like it had something spilled under there" and "no evidence of any leaks inside the pack"

If you have discoloration on the base plate that appears to be some type of spillage, you have found your leak. I've found many modules with small cracks in the bottoms. One was even cracked in the groove where a temperature sensor was connected. Sometimes you'll see significant corrosion along the edges where the mounting screws attach to the modules. Sometimes you'll see evidence of some type of pooling only in the area under the modules. Only a few times have I actually seen dampness, usually it looks like a dried up puddle.

And you can get pH test strips from any place that sells pool supplies, including Wally World.
or just lick it....you'll know pretty quick...

 

I wouldn't lick it, ewwww

 

I’d replace it but be mindful of the 48 inch pound torque.

Bet that was the failure.

 

$1950 is a good deal, I would buy new. The Vegas heat has already destroyed that pack you have in the car

 

I have had to fix such problems on two '05 Prii just within this week alone. It appears to me that its either this problem is common to the '05 Prii alone more.

Have you tried clearing the codes and see if it comes back again? If you did, and it still returns, then you know the fault code(s) wasn't intermittent.

The subcodes displayed pretty much has given you the lead.

Symptoms:
1. On the two Prii, the caution red triangle lights, VSC were lit on the dash
2. Vehicles seems to be working "perfectly" according to the owners.

At least the was AC system was chilling.
For one of the Prii, it had a p0AA6 code, and whenever the car us turned off, you got to either clear the code or disconnect battery cable before it starts.

On another of the Prii, it had only a p3009 code. This doesn't require battery disconnection for it to start up immediately after switching the car off.

What I did;
Cleared the codes, and drove a while to see if the codes would come back. Sure, they came back within 3miles of driving.

Carried out some tests to determine if the fault was related to the transmission, compressor, HV battery pack, or even the HV cabling.

In my case, obviously I had a 526 sub code, which pretty much narrowed down the isolation fault to the battery pack area.

Diagnosis:
1. Opened up the battery case after taking necessary safety precautions.

2. Obviously, for the first Prii, there was visible electrolytic leaks on the modules.

3. Gradually disassembled the pack by removing the modules gradually, to trace exactly which one the modules were leaking.

4. Got my DVM, and started testing the modules OCV.

It was surprising to me that all the voltages were still reading about 7.8blabla volts despite the ruptures.

5. Identified #4 modules that had ruptures on the same sides of one of their cells.
The leaks were just so much, that it flowed like a cup of coffee from a jug.

6. Got so e modules from a donor Camry pack, discharged and recharged them, and finally performed same procedure on the battery pack, before installation.

7. Both vehicles are back on the road right now, with the first, used for Uber and taxify, while the second, its driven as a personal car by the owner.

8. Treated the corrosions on the bus bars, and the floor of the casings with lubrication oil, after washing off the corrosions from it.

PS: Be very careful with the HV pack in such a fault.
You could get electrocuted, of not putting on safety glooves.
While I was carrying out voltage tests on the pack in the rear of one of the car, I was kinda feeling some sharp like or pin like feeling on my knees. At first I thought I was being g stung by something, or so. So, when I did take measurements, I realised I was getting about 100V, which was the feeling of sting I was receiving.



Regards,
Dxta

 

Good job on repairing both those cars.

Just a clarification: INF code 526 does not point to the HV battery, it is a general code that just means there is a Hybrid Battery Voltage System Isolation Fault somewhere in the hybrid control system. It is the other INF code (611, 612, 613 or 614) that pinpoints where to look specifically. In your case this would have been a 612 for which the trouble areas are:

• HV battery assembly
• Battery ECU
• System main relay
• System main resistor
• Main battery cable
• No. 2 main battery cable
• Battery plug
• No. 2 frame wire
• Junction block

Hope that helps.

 

No reports on PriusChat so far.

1 year or 3 years, it is all pretty academic. There is no reason for a new replacement pack not to last at least as long as the factory fitted pack. The key is that the new pack has all new modules.

 

Thanks for the corrections.

 

I think if you install it yourself you still get the warranty

 

Install yourself, you won't need the warranty

 

The warranty is a moot point with a NEW battery from Toyota.
I would expect it to last as long as the original one if not longer.

Installing it yourself you get a 12month warranty.

Make sure you clean the HV battery fan!
You want proper airflow over the battery.
You'd be surprised how clogged up it can get.