P0A80. Good 12V batt. No other codes

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by xavier nicolas, Apr 7, 2020.

  1. xavier nicolas

    xavier nicolas New Member

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    2007 Prius
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    Hello everyone.

    I own a 2nd Prius (2007) with 187k miles.
    I got a master warning triangle with engine check light and exclamation mark. My mother in law was using the car when it happened and was able to drive it back to my place.
    A bit of history: last year, I got the same lights and after the car to a mechanice, they said the hybrid battery is bad and needs to be replaced. called a hybrid battery seller and after testing the hybrid battery, he said the battery is fine. cleared the code. car was fine for over a year until yesterday.

    this morning, OBD reader reported a P0a80 code with no other ones.
    I did a little research here and read that the culprit may be the 12 v batt.
    I checked the 12v battery voltage using the onboard computer and it seems fine. (when the car is off, it reads 12.4V, after pressing the start button without foot on the brake, it reads 12 and it goes up to 14 ish volts when the engine runs)

    I drove the car a little after clearing the code, and the Hybrid battery seems to charge and discharge fine. it fills up all the way to green and empties itself at (what seems to me) a normal pace.
    The warning lights came back on when the battery was empty (one bar in purple)
    I am going to drive a bit more and find out if I can gather more info.
    Any ideas on what it could be? bad cell? the whole thing?

    thank you in advance
     
    #1 xavier nicolas, Apr 7, 2020
  2. xavier nicolas

    xavier nicolas New Member

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    Update: the hv battery doesnt get charged anymore and only shows one purple bar... Car is only moving on combustion engine and slow
     
    #2 xavier nicolas, Apr 7, 2020
  3. bisco

    bisco cookie crumbler

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    hybrid battery

    12v doesn't sound too hot either
     
    #3 bisco, Apr 7, 2020
  4. xavier nicolas

    xavier nicolas New Member

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    Thanks for the replies.
    Any suggestions about replacement options?
     
    #4 xavier nicolas, Apr 7, 2020
  5. dolj

    dolj Senior Member

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    There is nothing to worry about here that a good charge up of the 12 V battery won't fix. Don't waste any more time on this, move on. If you do end up working on other parts, put the 12 V battery on a charger for the entire time, especially if you will be doing diagnostics with the car in ACC or IG-ON.
    What code reader are you using? It sounds like the one you are using is very generic and can only read the ICE ECM (and maybe the ABS ECU). There should be other DTCs (diagnostic trouble codes) set by one or more of the hybrid system ECUs.

    You will have a clearer picture if you know all the codes, but yeah, it does seem like your HV (hybrid vehicle) battery is not happy.
     
    #5 dolj, Apr 8, 2020
  6. ericbecky

    ericbecky Hybrid Battery Hero

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    I'd be happy to help chat through some ideas.

    Basically you may need a different reader or at least some adaptor that can be used with one of the diagnostic apps. This way you could see and provide live data.

    Feel free to call me at 608-729-4082 if you want to bounce around some ideas.
     
    #6 ericbecky, Apr 8, 2020
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  7. fotomoto

    fotomoto Senior Member

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    There are two kinds of gen 2 owners, those that replaced/repaired the HV battery and those that are about to. "Congrats" you're now about to move into the former category. :(

    Most failures occur one module at a time. You can repair/replace said module and wait for the next one to fail. There are 28 modules. Rinse, lather, repeat till..... or you can get a new battery and get many more years of reliable use. The first is cheap, the second not so much. Which is better can only be answered by each person. For me, it was getting a new battery after the third module failure.

    Call Eric.(y)
     
    #7 fotomoto, Apr 8, 2020
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  8. xavier nicolas

    xavier nicolas New Member

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    Thanks for all the support everyone
     
    #8 xavier nicolas, Apr 8, 2020
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