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2006, almost 120k miles...12V Battery or something else (rodents)?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by pricoaster, Apr 4, 2012.

  1. pricoaster

    pricoaster Member

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    Vehicle:
    Other Hybrid
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    Hi guys...so here's the story, I'll try to keep it brief but include as much detail as possible. Last night I stopped at a grocery store to pick some things up. I have a base package 2006 Prius (no smart key), so I always lock my door by using the fob button. When I pushed the button, nothing happened. Confused, I opened the front door and tried locking it with the automatic locks on the side door...still nothing. I plugged the key fob into the slot and pushed power, nothing. The green light on the power button was blinking. I also noticed the lights in the cabin were pretty dim.

    After a few mins, the security light started flashing (as it normally does when the car is off). I tried a few more tries and the car eventually turned on, but the red triangle was on. The clock was reset to 1:00, but if I remember correctly, the radio stations were still programmed, or at least it was on the station when I turned off the car. At this point, I decided to drive it to the dealer (a few miles away).

    They said they were getting some kind of odd error code. Something to possibly do with the transmission, but they weren't sure. They said it could be some rodent problems, as some wires seemed like it could have been chewed. I thought it was the 12V battery, since all the symptoms were there (key fob not working, dimmed lights). Also, my MPGs have been below 40mpgs recently, I normally average in the low 40s since my commute time to work is only about 10 mins.

    The dealer kept the car overnight to see if the charge on the 12V this morning would be low, since it may have charged a bit while I was driving it over last night. I just called them and they said the charge was fine, so they're continuing to diagnose the problem.

    Any idea as to what could be the problem? I've noticed no problem with the transmission (or whatever the Prius uses). The only thing I've really noticed is the lower MPGs (I think it's sitting at 39.0 right now) and a slightly louder engine when I accelerate (especially on the freeway). The 12V is the original, as I have not changed it since I bought it new in 2006.

    Any troubleshooting help is appreciated!
     
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  2. 2k1Toaster

    2k1Toaster Brand New Prius Batteries

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    Three
    I would replace the 12v first of all.

    When the car is off, the only thing powering it is the 12v battery. If things are going weird with the car off, it is the 12v.

    If the car is READY, and it is still having weird issues, the options are the 12v is soooo bad that is is essentially a short, or there is a problem elsewhere like the inverter.
     
  3. pricoaster

    pricoaster Member

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    I just got a call from the dealer and it is the 12V, so they're going to replace it. They said it continually needs to be recharged. The good news also is that there is now wire damage due to rodents. Phew!
     
  4. edthefox5

    edthefox5 Senior Member

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    Vehicle:
    2007 Prius
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    Two
    The classic dead 12 volt battery post.

    Its absolutely amazing how dealers are unable to figure this simple issue out without alot of head scratching. What's more amazing is at the drop of a hat or in this case an obvious symptom they don't try to upsell you on a new battery anyway.

    Dealers should stock the Optima and upsell that as the good-better-best battery.

    Anyway if I may recommend something a really helpful device to have is a basic 12 volt battery charger. The standard $49 model that has 2 Amp mode. Hook that up to your prius 12 volt using the front battery jump points under the hood once a month and you'll get very familiar with how long it takes to reach full charge.
    That time duration is a very good indicator of the batteries overall health. When it starts to take much longer to reach max charge then you know the battery is geting tired (suphated).
    They sell other more expensive chargers that have an anti-suphation mode to btw.

    But this monthly max charge will extend the life of the battery.
    Should only take about 5-8 minutes to bring a healthy charged battery to max charge.
    Alot of us here routinely charge the batterys in our cars.
     
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