Prius II 2009 ECU coding!!

No. But you might be able to follow the step-by-step workup for P0AA6 (and related subcodes) to fix the issue yourself :

https://attachments.priuschat.com/attachment-files/2018/04/145252_2006_Prius_RM_-_P0AA6.pdf

 

You likely have one or more modules inside the HV battery that are leaking electrolyte onto the case.

Do you have a copy of techstream, basic hand tools, and a DIY attitude to investigate or fix the above problem yourself?

 

In your original post you only mentioned INF code 526, which is the preliminary one the car sets before it has pinned the fault down to one area. But in your post #5 you also have a Techstream screenshot showing INF 613, which is set after the car conducts further testing after the 526 and confirms the fault is in the gearbox. So when you write:

you're indulging in wishful thinking. Unless you have actually obtained a megger and followed the workup steps and eliminated the gearbox as the problem.

Nobody on an internet forum can make you fix your car if you don't want to, but in that case you might want to begin your search for your next car. You may succeed in keeping this one going for a while by pretending there's no isolation fault. Or a second fault could develop, resulting in a short circuit and disabled car.

 

If I were in your situation at this stage I'd find a spare hybrid battery pack and swap them and see if that helps focus the diagnosis. In my direct experience as well as from years of reading on here it's rarely the inverter or stator in Gen2 Prius when this error code comes up.

 

This is not a case of only 526; the car has explicitly reported 613.

 

Not quite so fast ... SFO gave you the repair manual section up in post #2. Look at the diagram on page HV-425. The 613 code means the problem is somewhere in the dotted rectangle labeled "transaxle area". That includes MG1 and MG2 as possibilities, but also some of the inverter and the wires between them.

Your next step is to look at the top of page HV-427, where you see that the 613 code sends you to procedure "C", which sends you to step 18 (that's on page HV-434). That's where you'll find out whether you're looking at a transaxle or an inverter.

 

I wouldn't say for sure in my experience... Loose connections in a hybrid battery pack can create all kinds of warning lights that point to problems with the inverter and electric motor. Been fooled enough times by that to not ever accept that conclusion until I've swapped the pack out with one I know doesn't have any issues.

 

Unless you have a known-good battery pack readily at hand for cheap or no money, the megger test (step 18) will be faster and a lot cheaper.

If you look at the way that step is laid out, you either end up definitely finding a transaxle problem, or not. If you do, you're done; that's a positive diagnosis.

If the megger test doesn't definitely find you a transaxle problem, the manual tells you to swap the inverter; that's a diagnosis by elimination (613 means transaxle or inverter, megger didn't find transaxle problem, go with inverter).

That would be the point where, if you were persuaded by PriusCamper's idea that a faulty battery could give you a fake 613, perhaps you would try with another battery, before assuming the elimination diagnosis of the inverter had to be right.

In the first case, where you bring out the megger and it independently confirms a transaxle problem for you, there wouldn't be any point fussing with the "maybe it's a fake code because battery" idea, because in that case you already know better. Then you could just save the battery money and put it toward what you know you need instead.