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Trouble codes = new aux battery?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by TinyBabaganoush, Apr 19, 2011.

  1. TinyBabaganoush

    TinyBabaganoush Junior Member

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    Took my wifes '06 in to the dealer today. On Thursday she lost power and "a bunch of lights and alarms went off." I know, real helpful huh. After about 15 minutes the car would start without the the check engine lights/alarms (including triangle/!) and she was able to drive it home. Toyota found the following trouble codes. P0A08, C1241, B1421, B2795, and C2318. Their solution was new aux battery for which they wanted to charge me $370 installed. I took the battery home myself and installed it. ($140. $230 for labor!!??) Anyway, after we got the car home I brought up the battery diagnostic on the info display. Battery charge was at 12 volts without load, dropped to 11.9 when I powered up the accesories. Does this sound like a troubled battery? It does have 5 years on it so I don't have a problem with replacing it, but I'm a bit worried that this problem may pop up again. Toyota did also replace the hybrid cooling pump (HV water pump) for recall service.
     
    #1 TinyBabaganoush, Apr 19, 2011
  2. 2k1Toaster

    2k1Toaster Brand New Prius Batteries

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    Sounds like for once the dealer noted it was the aux battery throwing false codes and didn't take the codes at face value. You may have a winner tech there.

    They were (judging from what you posted) correct. Did you make sure to get the SKS version of the battery if you have SKS? It is just a tad larger capacity to account for the extra small parasitic drain.

    It is more than likely that battery has been sitting on the dealer shelf for a few months and is low in charge. So drive it for a few days to charge it back up, and all will be well.

    The problem will pop up again when this battery dies. :)
     
    #2 2k1Toaster, Apr 20, 2011
  3. richard schumacher

    richard schumacher shortbus driver

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    Did they replace the inverter coolant pump before the Thursday incident? If so then they may not have got all the air out of the coolant loop, which means the inverter isn't working all the time, which could have killed the 12V battery.

    If they replaced the pump after the Thursday incident, then everything may be OK (except that the battery they sold you may have been sitting around for a while and discharged partially.)
     
    #3 richard schumacher, Apr 20, 2011
  4. TinyBabaganoush

    TinyBabaganoush Junior Member

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    Actually the battery charge that I reported was for the old battery. The new one has full charge. I was worried that the readings I got from the old battery didn't look so bad as to immediately need a new one, and that it probably wasn't the source of the freakout.
     
    #4 TinyBabaganoush, Apr 20, 2011
  5. 2k1Toaster

    2k1Toaster Brand New Prius Batteries

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    A healthy 12v battery should never go below 12v in a Prius. On a traditional car, it should never go below 12v unless cranking and then 6v to 8v is common for less than a second in spikes.

    A new 12v should be between 12.4v and 12.6v idle with no load.
     
    #5 2k1Toaster, Apr 20, 2011
  6. qbee42

    qbee42 My other car is a boat

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    By idle he means not connected to anything. Don't confuse this with an idling car. If the car is idling (Ready in the case of the Prius) you will see about 13.8V.

    Tom
     
    #6 qbee42, Apr 20, 2011
  7. 2k1Toaster

    2k1Toaster Brand New Prius Batteries

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    Yes! Sorry.

    I mean with no load. When "idling" (alternator spinning in a normal car, or the prius in READY) it will be 13.8v or 14.4v
     
    #7 2k1Toaster, Apr 20, 2011
  8. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Now that this has been clarified, I would say that voltage measurement shows the battery is only ~50% charged. A new AGM battery out of the box should read ~12.9V.
     
    #8 Patrick Wong, Apr 20, 2011
  9. andyprius

    andyprius Senior Member

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    The repartee was quite humorous and your comment too Pat!:D
     
    #9 andyprius, Apr 30, 2011
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