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PSA: Don’t get Dorman Products replacement Hybrid Battery (Also, help? P0AC0.)

Discussion in 'Newbie Forum' started by Caleb2007, Dec 1, 2020.

  1. Caleb2007

    Caleb2007 Junior Member

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    About a year and a half ago I bought a used 2007 Toyota Prius with 96k miles on it. To make a long story very short, after 3 months I was getting error codes, the triangle of death and decreased mileage. I spent hours on this forum, and got mixed answers on some of my questions, but ended up being helped by the absolute homie, @PriusCamper. (Special shout out to him, seriously he was super helpful and I should have thanked him more back then.)

    Anyways, after getting a bluetooth OBDII reader and the Torque app, I found one of the HV modules was weak… And to make a very long painful saga incredibly short, I was able to (barely) fulfill the warranty on that Dorman HV battery (which was less than 2 years old at the time). I got the battery for free, and with the confidence booster from @PriusCamper , and many youtube videos, I took out, and replaced the HV battery myself.

    I was/am incredibly proud.

    Fast forward to this year, I ended up having to replace it YET AGAIN. This replacement battery was actually still technically under warranty (I had 2 weeks left).

    - Side note, Dorman HV batteries used to have a 3 year warranty, but switched to a 1 year warranty (probably because they found out they suck). -

    So, I went through the same process and replaced the battery myself for a second time this summer.

    That was just a few months ago, and I am now having more problems with the triangle of death. On and off, I am getting lights and the code P0AC0. Sometimes I power up the car and it’s totally fine, and sometimes I turn it on and I get lights and it feels ok, and sometimes it feels like it doesn’t know if it wants to engage the engine or not...

    I have suspicions it is the 12v battery. But, I also have suspicions it could be the ECU (which I don’t know much about). I have not checked for corrosion on anything (as I don’t have a ton of time or especially knowledge on where to look and how to clean it), but I am also not sure if it would be corrosion as I live in a desert climate (granted it does get cold and a tad wet this time of year, but I still doubt that would have a direct effect on it(?)).


    TL;DR

    Dorman HV Battery Bad. I was able to replace it twice under warranty. Getting error code P0AC0 intermittently for unknown reasons. Help.


    Also, again, shout out to @PriusCamper
     
  2. vvillovv

    vvillovv Senior Member

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    Start with the easy stuff first. You mentioned above it could be the 12 volt. Nail that down .... Is it the 12 volt?
    Take a multimeter / voltmeter and get the volts for a few times before you start the prius.
    Leave the hood open and recheck the 12 volt batterys voltage after the prius is running. And write them both in a log. Take notes. The car behaved like this! Date and Time Anything else you think of too.

    That's the easy stuff, get that done first.

    Now the shiznits.....
    Just so you get a feel for what's possibe take a look at the P0Axx error codes POAC0 is there too....
    It's the Prius Traction Packs Current Sensor (but you probably already know that if you looked)
    OBD diagnostic of Auto: DTC(Diagnostics Trouble Codes) P0Axx

    There are Toyota sub codes for POAC0
    and here are two of them I found.
    P0AC0-123 - Toyota Diagnostic Trouble Code (DTC) Definition, Causes and Diagnosis
    and
    P0AC0-817 - Toyota Diagnostic Trouble Code (DTC) Definition, Causes and Diagnosis

    If you know how to get pink codes bu shorting 2 pin of the ODB2 connector socket - get the blink codes and the sub codes currently set in your ECU(s)...
    Be Careful ..... shorting the wrong pin holes in the ODB2 socket can blow big fuses or worse....
    Besides, while looking at the ODB2 connector socket you are usually looking at it upside down and backwards.... Have the detailed diagram of the connector and the pin socket locations with you when you are putting in the clip.
    search how to get prius blink codes.

    And here's a Toyota TSB from 2009 that should help with narrowing down the issue(s)
    http://media.fixed-ops.com/Toy_ServiceBulletins/sb0166t09.pdf

    The links are just as much for the tech guys here willing to pitch in as for you.
     
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  3. PriusCamper

    PriusCamper Senior Member

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    Thanks for the kind words... In my experience this problem leads me to where the voltage sensor harness plugs into the Hybrid battery ECU. That plug gets corrosion and the Toyota Stealerships will say $800 for new ECU and $3K for new battery pack. But you can also get in there and just clean up the mess and make sure nothing has shorted out yet. Worst case scenario you put in a new $50 voltage sensing harness (Wire Frame No. 2) and a used ECU for $100. But try the cleaning and inspecting option first.
     
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  4. fotomoto

    fotomoto Senior Member

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    The current record as reported by a PC member for dorman replacements by one owner: six!

    Once I quit messing around with the very labor and time intensive process of rebuilding and maintaining a failed pack and got a new OEM for my 06 with only 50k miles three years ago, all my reliability and drivability issues disappeared.

    FWIW
     
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  5. Caleb2007

    Caleb2007 Junior Member

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    Are there any online resources for safely cleaning the proper parts if there is corrosion? I have found a bunch of videos implying that's what they did, but none of them show how they did it. I know how to get into it, and I can guess as to what I'm looking for, but guessing isn't my favorite thing when dealing with cars/electricity.
     
  6. PriusCamper

    PriusCamper Senior Member

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    I usually pull the ECU and take off the cover to confirm nothing has shorted out where the plug socket attaches to the circuit board. Then I use a tiny piece of sandpaper to sand the corrosion off the pins. In many cases the the plug and socket will have fried the pins and melted the plastic and you have to replace everything, but hopefully you're addressing this before it's turned into that problem.
     
  7. vvillovv

    vvillovv Senior Member

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    my recommendation is a techstream subscription so you have access to the repair manual.
    https://techinfo.toyota.com/

    I got the repair manual a month after out first hybrid. I didn't use it for 8 years, but I've been using it now for 7.

    Video's are great, when you can find one that makes sense to you. I wouldn't dig into the traction pack or the hybrid system without the manual.
     
  8. Caleb2007

    Caleb2007 Junior Member

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    UPDATE: I didn't notice any corrosion and I have replaced the 12v. I'm still getting the lights on and off. To be fair, I'm not entirely sure what I'm looking for when it comes to corrosion, or what I'd do if I found it...

    Posted via the PriusChat mobile app.
     
  9. rjparker

    rjparker Tu Humilde Sirviente

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    Any advice that suggested getting a used hv battery was terribly wrong. Even if it has a painted case to make it look better. Even if it is reconditioned, rebuilt, guaranteed or reconstituted. You can't change the laws of physics or chemistry.

    Laws of Physics Kansas City.jpg

    All of those options lead to regret and rework. You can't trust your car because reliability is gone. If you insist on diy disassembly / reassembly to save money and get an ego boost, buy new cells.

    Be careful of scammers right here on this forum. They are plentiful and some are well known members. Lead horse to water.jpg
     
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