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Odd random failures. 12v going dead?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by created, May 23, 2015.

  1. created

    created New Member

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    Power steering out, all gear lights and fuel gauge blinking simultaneously, abs light on, flat tire light on, windows won't work (except driver side still works), display not showing any data,

    Everyone else works though. I can start the car and drive except it's hard to steer without PS.

    There's no triangle or engine codes. I have a scanguageII. It shows nothing out of ordinary. SOC is 55%. I also put the car in diagnostic mode and it shows no codes or errors there either.

    I'm just stuck with no ideas except that I've read things start to go crazy when a battery is going dead.

    Any suggestions would be greatly appreciated. Thanks much!
     
  2. JC91006

    JC91006 Senior Member

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    Some of those symptoms seem to be 12v related. But the power steering not working is a completely different issue. I would change the 12v first if it's over 5 years old.
     
  3. Patrick Wong

    Patrick Wong DIY Enthusiast

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    A question: Did all of the symptoms appear simultaneously or did they develop over time?

    I have two ideas:

    1. Measure the 12V battery voltage both when the car is IG-OFF, and when it is READY.

    2. Get Mini VCI so that you can retrieve the DTC logged by your car. I guarantee that fault codes exist if the ABS light is on.
     
  4. Freedom

    Freedom Active Member

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    My 12v battery lasted just over 4 years. Then it was as if my Carmine was possessed! Changing the 12v corrected -- exorcised the demons, lol.

    I agree with C91006. the power steering is a separate issue. Start with the 12v and perhaps you will get better diagnostics once that is resolved.
     
    #4 Freedom, May 23, 2015
    Last edited: May 23, 2015
  5. Mendel Leisk

    Mendel Leisk Senior Member

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    Excise 'em, dammit. :ROFLMAO:
     
  6. Freedom

    Freedom Active Member

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    Yep, typo, fixed it now ha haa.
     
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  7. created

    created New Member

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    It happened all at once. Like a light switch and all the sudden steering was hard and noticed dash screen was void of info. image.jpg
     
  8. created

    created New Member

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    No telling how old the battery is but its a yello top. I believe one that optima made specifically for the prius. Shows quite a bit of corrosion on the ground connecting post.
     
  9. Beachbummm

    Beachbummm Senior Member

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    never had one take out the power steering ..how is the blinker fluid? has it been changed in the last few weeks?
     
  10. bisco

    bisco cookie crumbler

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    corrosion is a bit unusual, i would replace it. any water in the battery area?
     
  11. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Regarding the power steering system, check the following two fuses: 7.5A ECU-IG and 50A EPS.

    Regarding the combination meter, check the following three fuses: 10A GAUGE, 15A DOME, 7.5A IGN.
     
  12. created

    created New Member

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    Got it fixed. Took a new 12v Batt and thx to Patrick I checked fuses and there was a blown 7.5a ECU-IG fuse. I changed the batt 1st and then replaced fuse. The fuse was probably the culprit of all the sudden & simultaneous failures, but also the 12v Batt was getting down low enough that it was time to be changed. Anyways I'm back on the road again (this time with spare fuses abord.

    & Btw this is on a near 250k mile car. When you're rolling with this many miles and something goes out... It could be anything lol

    Thx for your help and suggestions guys!
    I appreciate ya!
     
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  13. Mendel Leisk

    Mendel Leisk Senior Member

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    Hope so. The only thing, when I hear fuse blow, I think: how come?

    Knock-on-wood it's all good. :)
     
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  14. jdenenberg

    jdenenberg EE Professor

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    Fuses do sometimes fail on their own. Nothing is perfectly reliable. If there was a cause for the blown fuse, it will happen again.

    JeffD
     
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