Red triangle but good mpg

More than likely you have the hybrid isolation fault this requires you to clear the code to generally drive the car starts and drives normally charges relatively normally gets pretty normal gas mileage and so on

 

What are the trouble codes that are being cleared? List them, and you will get some answers about what the problem is with the car.

PS, do not buy an old Prius unless you have experience fixing cars. Old hybrid cars can be very expensive to fix if you can not do the work yourself.

 

The P0AA6 code is the ONLY (hybrid system RTOD) code that will allow you to continue driving normally until you shut the car off. At that point, it locks you out of going READY, so the next time you need to use the car, you need to reset the codes by disconnecting the 12v battery for a minute. If the P0AA6 is being caused by the HV battery, this can be caused by HV battery modules that are still in excellent condition (capacity wise) but have developed a voltage leak to the steel battery case. Sometimes this is caused by electrolyte leakage. Sometimes it is caused by microcracks on the bottom of the module where the small machine screw fastens the module to the case. The screw threads into a metal insert that is pressed into the plastic body. Sometimes it will develop a crack allowing electrolyte inside to make contact with the insert. Sometimes this can be solved just by putting a piece of electrical tape under that module and leaving that screw out.

If it's a P0AA6, 90% or more of the time it's a battery issue. Can also be AC compressor motor, inverter, cables, transaxle, etc.

 

Could be, battery faults are a common cause for isolation codes, but I would want to check all systems for codes with a capable scantool.

Here's a thread that reviews several apps and devices for a smartphone. You would want one that can retrieve INF sub codes to get more details about the fault.

INF codes are located in freezeframe data. For P0AA6, you want to try and power up the car twice - it won't go ready the second time. The first time sets a 526 "general" isolation fault INF. The second time will set another INF that narrows down the fault area.

https://priuschat.com/index.php?posts/3290690

Posted via the PriusChat mobile app.

 

A P0AA6 code can often turn out to be something fixable without spending nearly that much. It is not the kind of code that has to mean the battery modules are badly worn out in capacity or anything. Even if the isolation fault is within the battery (INF code 612), it might be something than a module leaking electrolyte, and even if it is a module leaking electrolyte because of a small crack, say, there could be a good argument for just replacing that one. (This can be in contrast to, say, P0A80, which usually appears when all the modules are pretty bad capacitywise, and efforts to replace just one or two worst ones often turn into whac-a-mole.)

A lot comes down to what you find when diagnosing the P0AA6.

You haven't said what the five other codes are.

 

Attach a photo of the error diagnostics.
Dr.Prius does it display any errors regarding the hybrid system?

 

You still want to pull the INF codes to see if it's the battery or something else.

There are MANY threads about "just" replacing a few modules. Use the search function in the Gen2 forums.

Short form, it's a crapshoot with a low chance of being reliable. The "best" inexpensive route is to find a set of (original) modules from a late model Prius or Corolla hybrid (be sure to find a model with NiMh, not lithium-ion).

Otherwise the standard response is a new OE pack from the dealer.

Any "refurbished" pack is made of used modules (that MIGHT have been charge - discharge cycled to improve capacity then tested & matched with the rest - OR NOT). It might last 2-3 years, might fail in 2-3 weeks. Who knows?

Posted via the PriusChat mobile app.

 

I follow the "crapshoot just replacing a few modules" reasoning when the reason for replacement has to do with module life/capacity (P0A80-type issues). The rest are probably not far behind.

I don't follow that reasoning so much if the reason for replacement is a P0AA6 and it turns out, say, one module is leaking goo. If the other modules aren't leaking goo, replacing the one that is sounds pretty ok to me.

It will be important, naturally, to find a module well-matched to the rest of the pack. And it might be important why the module leaked goo. If it leaked around the terminal, and if it's known that happens commonly at a certain age (I don't know if that is known), then perhaps again other modules are not far behind. But if it's leaking from, say, a crack around the bottom screw insert, I'm not sure it necessarily follows that others are going to do the same.

 

Could you post a photo of the battery values from the Dr. Prius program?
How big is the temperature difference between the sensors?
High internal resistance causes the faulty module to overheat and the excess pressure ruptures its upper part.
This does not lead to a fire, but it is no better.
The high-voltage battery becomes unusable and needs to be replaced.
2005 Prius with 193K miles and exploded battery module | PriusChat

 

That's the real crapshoot in my book. Define "well matched", and how would Joe Average Prius owner determine that?

Posted via the PriusChat mobile app.