Whats Wrong with my prius

The codes are... "Replace hv battery" (P0A80) and "battery block 11 becomes week" (P3021)
You can find all the codes here...
Complete list OBDII codes - GreenHybrid - Hybrid Cars
It looks like you need to replace a module.
Read this thread...
Gen II Prius Individual Battery Module Replacement | Page 11 | PriusChat
And...
Prius Battery rebalance thread | PriusChat
They should both be a HUGE help.

 

This happened to me and I'm in the midst of fixing mine right now. Including the tools and everything needed to rebuild the battery it's going to/has cost me around $250

 

Your hv battery has block #11 going bad. Probably need one or two modules. If you are I

 

If you live in los Angeles, ca. Call me 3233502278

 

I see you are located in the Bahamas.
As others noted, you have some weak cells in block 11.

If you plan to do the work yourself, let me know. I can send parts and talk you through a few things. Or if you have a reputable independent shop, I could help them as well.

It's unlikely that you need an ecm. But as you noted you can find a used one for much less than new.

We can talk via email, or if you have Skype we can give that a go. Drop me a line.

 

While the Scangauge is a good unit for monitoring while driving, if you want to completely troubleshoot the battery system, you would do well to get the mini VCI (eBay and elsewhere). This gives you as much info as possible. Your dealer appears to be less knowledgeable than the many helpers here on PC. These reports of P0A80 are becoming almost a daily event now, so you are in good company.

 

it is amazing how many batteries we've seen the last few months.

 

This is why I changed my shop to full time last year. Prior to this there wasn't enough out-of-warranty work.

 

Uart mentioned in another thread today about the failure rates of HV batteries being in the 2% range, surveyed by I forgot whom. How accurate do you think this 2% replacement rate is? What has been your experience?

 

By you asking this question, you might want to get it done by someone else and you watch how it's done. Maybe after that, you can try it on your own if another cell fails.

YES YOU CAN KILL YOURSELF DOING THIS!

 

I can guaranty that if had you have paid them the $2000 that it wouldn't have fixed the problem. I can also guaranty that you would never have seen one cent of that $2000 refunded. Instead the dealer would have steadfastly maintained that there *really* was problem with that ECU and that now there is another *different* problem with the HV battery - and that will be another $4000 please.

Lucky for you that you did some research yourself on this before letting the dealer cut lose with your wallet.

 

Battery balancing in its present state of knowledge is something you could do with small investment, but it is time consuming. The car would be out of service for a while. Start with some of the threads on how to proceed:
Gen II Prius Individual Battery Module Replacement | PriusChat
Prius Battery rebalance thread | PriusChat
HV Battery Rebuild - Cell Capacity and Balancing Help | PriusChat

There are other threads which can be searched out as well. Don't be put off by the voltages, people work with this equipment daily without problem. This is helpful:
Prius battery exploration

 

I am having the same problems with my 2005 Gen II Prius. They originally told me it was the ECM, so I had them replace it (Cost $2000), then it didn't fix the issue, they said it was the 12V battery, replaced it- Nope, still didn't fix the issue. Today they say it's the Hybrid Battery...UGH. I will not buy another Toyota. I owned a Camry (which was a perfect car), then a Lexus which was in the shop and I spent more on it for fixes than what I paid, now I'm driving the Prius, and I love it, but a new Hybrid Battery is going to be $3,100! Ugh. Time to say goodbye.

 

After all that money spent, will it be easy to let go?

 

If someone told me that a $2000 part would fix a problem and it didn't, I'd be telling them to take it right back out or face a lawsuit. Have you contacted Toyota corporate about this, or are you just accepting it as "bad luck"? They are a dealership, and should know better and stand behind their work.

Nexus 4 ?

 

+1 I would hold the dealership responsible as that is their diagnosis of the problem.

 

Sounds like a real crap shoot.

The reality is that ECU's are generally very reliable and rarely fail. Unfortunately for us however, there's a darn good profit margin for dealer in replacing them. Sometimes I even wonder if some of these ECU failure misdiagnoses are no accident.