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2004 - beeping after I shut engine

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by ggarb, Oct 29, 2012.

  1. ggarb

    ggarb Member

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    I have a 2004 with nav; 145,000 miles.

    Toyota replaced the hybrid/traction battery this summer at 139,000 under warranty.

    I replaced the 12v accessory battery a year ago with the new Optima direct replacement.

    In the last few days, I've bern getting a beeping after I shut the engine off and open the door. And when I next get on the car and start it, it's acting like the 12v battery is low. I've even had problems with the smart key opening the doors.

    I get the same beeping when I get in the car.

    I've ruled out a problem with the key fob.

    It feels like I have a drain on the 12v somehow when I'm parked.

    Reading codes with the ScanGuage II - no codes found.

    Next I'll read the 12v accessory battery voltage in the MFD.

    Any other suggestions?

    Thanks,
    /Gordon
     
  2. ggarb

    ggarb Member

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    (Sorry for the double post; the Tapatalk software on my phone didn't clearly indicate that I'd successfully posted.)
     
  3. cwerdna

    cwerdna Senior Member

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    key not working | PriusChat

    The car will beep after shutdown if you've driven for 20+ minutes (IIRC) w/a low key fob battery. Change it. I've personally encountered this before.
     
  4. ggarb

    ggarb Member

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    I worried that it was the fob battery. Also, my fob is looking pretty ugly, with some of the rubber worn off the lock button. So I took the second fob, which I've never used, and put in a fresh battery. I then removed the battery from my worn fob - just to make sure it wasn't transmitting. (This battery I installed in the fob last November.)

    Didn't fix the problem.

    In fact, the 12v is dead now, and I had to get a jump to get home.
    Reading the voltage in the MFD it showed 13.7v
    Turning the car off it's now dead - I'll have to jump it again to get it to try to charge the 12v battery.
    I'll let it run for 30 minutes and see what the voltage gets to.

    Perhaps the fob battery WAS low, but I think I'm seeing another problem too now.

    :-(
     
  5. cwerdna

    cwerdna Senior Member

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    The 13.7 volts while in READY mode doesn't tell you the state of charge of the 12 volt. However, that is a little worrying.

    Leaving it for 30 minutes will not charge it up that much. Patrick Wong (aka a repair expert here) 2005 Prius beeps when door is open, then won't start | PriusChat has suggested 8 hours.

    I bought Amazon.com: TecMate TM-141DUAL OptiMate 4DUAL 0.8Amp Weatherproof Desulfating Charger/Maintainer: Automotive (straight from Amazon, not a 3rd party reseller) to help keep my 12 volt topped off since I have only short drives now.
     
  6. richard schumacher

    richard schumacher shortbus driver

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    13.7V is the output of the electrical system charging (or trying to charge) the 12V battery. It is not the battery's output voltage. Measure it again. A voltmeter with the car off would be completely unambiguous.
     
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  7. jadziasman

    jadziasman Prius owner emeritus

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    Wow, that's weird. 13.7 volts indicates the aux battery is being charged. Check for a loose connection at the battery.
     
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  8. ggarb

    ggarb Member

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    Understood that the 13.7 means the electrical system is dumping that into the battery to charge it, it's not the output of the battery.

    Once I get the 12v battery sorted, I still worry about the root cause of it becoming discharged.
    Is the one year old Optima battery bad?
    Is there a voltage drain somewhere?

    /Gordon
     
  9. ggarb

    ggarb Member

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    I'm going to leave it as a dead thing in my driveway tonight, and tackle it tomorrow in the light of day.
    I'll probably jump it again, so I can open the hatch to uncover the 12v accessory battery to check for loose connections, and to check it with a voltmeter.

    Oddly enough, I have a spare Optima battery (warranty replacement for a defective one I installed in a friend's Prius) so I might swap it in, after measuring the voltage of it out of the box.

    Or I might just take out the suspect 12v battery and put it on an external charger for a couple of hours, getting readings from a voltmeter before and after. That seems like the best next step.

    /G
     
  10. ggarb

    ggarb Member

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    I found the root cause.

    Yesterday I set out to swap in a new Optima battery, so I could both drive to meetings, and charge the battery that was showing low voltage.

    When I unvovered the battery I wiggled the cables to see that things were secure. The ground connections to the frame was loose!

    This groubd connection is a metal loop eyelet that is crimped pn the end of the cable that goes to the ground (-) terminal of the battery. A bolt then goes through the loop, and a flat metal washer. This bolt screws into a captive nut in the car's frame. This part of the frame is painted, so the current must go through the threads.

    In my case, the screw was loosened about a quarter inch, so the metal loop was not making a solid connection to the bolt.

    I put in the new battery, and I stacked two split lockwashers on either side of the loop as the bolt goes through them. The lockwashers should keep pressure on the bolt, preventing it from loosening. I also tightened it more agressively than I probably did a year ago.

    So far everything is working just fine.

    I'll probably make it a point to check this connection every six to twelve months going forward.

    Thanks to everyone for the help an advice. ImageUploadedByTapatalk1351710184.985538.jpg
     
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  11. HaroldW

    HaroldW Active Member

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    Your old optima is probably in need of a re-charge only. Don't throw it away as the reason folks go to the optima is they can be run down more without effecting them. It is probably a good 12v !H
     
    ggarb likes this.