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Replaced 12 Volt Now P0A80 HV Battery and C1310 HV Malfunction

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Paul Schenck, Apr 4, 2017.

  1. Paul Schenck

    Paul Schenck Active Member

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    My mom had her 2004 red triangle come on. I left my code reader out of town and so we took it to Lexology and they ran codes
    C1241, C1300, P0A80, C1310 they said recent TSB recommended replacement of the 12 volt and the ECU because their test indicated the HV Battery was good.
    My question is what test can be run on the HV battery to come to that conclusion?
    Patrick Wong can you educate me?


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  2. Paul Schenck

    Paul Schenck Active Member

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    I would assume it's time to replace the HV Battery not the ECU ??


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  3. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I would not assume that either needs to be replaced.

    1. How old is the 12V battery?
    2. What prevents you from replacing it? C1241 indicates low battery voltage.
    3. I don't know what test your service center would have run other than looking at the module pair voltages reported by Techstream.
    4. It is not clear what ECU would need to be replaced. C1300 points to a fault with the skid control ECU but that might be an erroneous code caused by low battery voltage.

    I suggest you start by replacing the 12V battery or at minimum, putting it on a charger and getting it fully-charged. Then see what happens when the battery is reconnected.
     
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  4. Paul Schenck

    Paul Schenck Active Member

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    I did replace the 12 volt as suggested. From there the P0A80 returned pending, then confirmed.

    Drove it a mile and the charge on the HV system fluctuated widely. Decided to replace the HV Battery and now all is well. Thanks


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  5. bisco

    bisco cookie crumbler

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    well done. did you put in a new toyota battery?
     
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  6. Paul Schenck

    Paul Schenck Active Member

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    It was a spare I bought a year ago before I replaced the engine and transaxel in mine


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  7. bisco

    bisco cookie crumbler

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    nice. all the best!(y)
     
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  8. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Good.

    It appears you got bad advice from your service location?
     
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