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2008 Prius has Code C1241 but 12v Battery is Fine

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by HTprius, Sep 17, 2023.

  1. HTprius

    HTprius New Member

    Joined:
    Sep 17, 2023
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    Location:
    San Diego
    Vehicle:
    2008 Prius
    Model:
    Touring
    The red triangle warning light is coming on intermittently in my 2008 Prius. It comes on, beeps, the screen tells me "Problem," and then it goes away again for a few seconds.

    I checked with an OBD2 scanner and got the code C1241 which according to Google has to do with the 12v battery. I just replaced the 12v battery ~6 months ago though. I went back and check the terminals were connected tightly and then checked the battery voltage using the built in test feature, and it has a voltage of 12.3 V, so it should be good.

    The car is old and still on its original hybrid battery (175,000 miles) so I wouldn't be surprised if that was the issue and I need to get it replaced. It's just the code doesn't seem to be related to the hybrid battery so I don't want to replace something that isn't the problem.

    Misc info: the car still runs fine, although the battery is definitely showing its age. It goes from full charge to almost empty fairly quickly. With that said, it hasn't been a problem until now.

    Do you think the hybrid battery is the problem? Or could it be something else I can troubleshoot/check before making such an expensive purchase?
     
    #1 HTprius, Sep 17, 2023
  2. HTprius

    HTprius New Member

    Joined:
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    Location:
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    Vehicle:
    2008 Prius
    Model:
    Touring
    UPDATE: For anyone having the same problem. I checked the oil and it was bone dry. Last week I had an oil change and so today I went back and had them redo it. Apparently they didn't tighten the filter all the way. Smh.

    I have no idea why low/no oil would cause C1241 to show up, but the code is gone now, yay!
     
    #2 HTprius, Sep 17, 2023
    SFO likes this.
  3. dolj

    dolj Senior Member

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    Vehicle:
    2007 Prius
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    Google is wrong.

    That code has to do with the power arriving at the skid control ECU.

    A source of good information is in the repair manual. It has all the details of troubleshooting this code too, should that code come back.

    I doubt your oil sump was bone dry because if it was you would be having all sorts of engine problems. Maybe you caught it in time. In any case, I'd be checking the oil level frequently as you likely have an oil burner now.
     
    #3 dolj, Sep 18, 2023
  4. ChapmanF

    ChapmanF Senior Member

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    While it's not a bad idea to go look at the 12 V battery for a C1241 (after all, "power arriving at the skid control ECU" could have something to do with the battery), once you've gone and looked there and it wasn't the problem, the C1241 just means to keep looking along the path that brings the power to the ECU, until you find the problem.
     
    #4 ChapmanF, Sep 18, 2023
  5. SFO

    SFO Senior Member

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    Welcome to PriusChat!!
    Which OBD2 scanner/app are you using, as many are not hybrid compatible.
    Unless known to be clean, always best to clean up the MAF, butterfly valve/bore, when disconnecting or replacing the 12v source.
    Before your HV battery fails, now would be a good time to balance/cycle by using a gridcharger/discharger, either DIY, or from known retailer.

    FYI : you're moderated until you've posted 5 times.
     
    #5 SFO, Sep 20, 2023
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