Help! DTC P0A08, P0A09

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Toni 1965, May 22, 2021.

  1. Toni 1965

    Toni 1965 New Member

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    I have a death triangle,VCS and brake yellow lights. DTC P0A08, P0A09.
    Also I have red car and accumulator on LCD.On a diagnostic mode when on ready mode shows 13.8 V.
    I have no problem in driving the car.I`ve seen a video that 13.8 V is normal, but when on Ready mode before driving is normal to have 14.4 V. and after it falls to 13.8 V. But I have not such figures, not above 13.8 in Ready mode before driving.When the problem appears in the beginning there was a couple ot times when the problem disappeared and I was able to clear errors , because they were in history mode.
    But now the problem persist as current mistakes.
    Is it likely to be failure of the Invertor or it is more likely due to cable and connection problems?
     
  2. rjparker

    rjparker Tu Humilde Sirviente

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    The lack of 14v after Ready just means the 12v is reasonably charged already. Your problem is most likely the inverter.
     
  3. bisco

    bisco cookie crumbler

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    how many km on her?
     
  4. Toni 1965

    Toni 1965 New Member

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    But when I start Diagnostic mode before READY It is stated 11.8 V for the 12V battery wich is low,Sometimes the red accumrlator and Red car on LCD disappear and the car is green.Should I make diagnostic check on C5 and H16 HV ECU connectors As it is recommended for testing wire harness and connectors?
     
  5. Toni 1965

    Toni 1965 New Member

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  6. rjparker

    rjparker Tu Humilde Sirviente

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    Part of the inverter charges the battery and the codes are suggesting that. However some charge is happening. I might change the 12v battery as a first step IF I did not want to take it to the dealer for a verification of what is fundamentally wrong.
     
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  7. dolj

    dolj Senior Member

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    Do you have a picture of the 'accumulator' on the LCD?
    Do you mean this: HV Battery Symbol.png or this: Main Battery Symbol.png ?
    It is always a good idea to follow the workup procedure to confirm the correct working of connectors and cables. It can save the needless replacement of expensive parts that are not faulty.
     
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  8. bisco

    bisco cookie crumbler

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    how old is the 12 volt?
     
  9. Toni 1965

    Toni 1965 New Member

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    3 years old. After drivng diagnostic check shows 12.5 V wich is normal.
    They tested 12 V battery and said it is OK. The Fact that in the beginning when problem appeared, it was from time to time, I think it is because of loose wire harness and connectors. It is prescribed from toyota to make diagnostic check , but I have problem to find where exactly is H16 HV ECU connector in order to measure resistance of the cables
     
  10. Toni 1965

    Toni 1965 New Member

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    Yes on LCD appears first picture and sometimes in the morning , when the car is cold it is not presemt and car on LCD is green.
     
  11. Toni 1965

    Toni 1965 New Member

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    Does anybody knows where the C5 connector is ? I need to find this in order to make a diagnostic check
     
  12. GabrielD

    GabrielD Member

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    H16 is just a part of the ECU connector. pic 1
    ECU is found under the gloves compartment... pic 2

    You can check it's OEM nr and see images on Google...

    later edit
    You need wiring manual to find exactly where the connectors are, here is a pic with C5... pic3
     

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  13. Toni 1965

    Toni 1965 New Member

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    Thank you very much!
     
  14. GabrielD

    GabrielD Member

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    Have you found what the issue is?
    If you need more to investigate terminals of ECU, here it is a file that can help you.
    But, I think you should check HV Battery...
     

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