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Flakey Smart Key?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by snijd, Oct 27, 2008.

  1. snijd

    snijd DIY or die

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    I recently bought a new smart key, and then took the car to the dealer for programming. The key seemed to work okay, although occasionally it seemed reluctant to unlock the car. Now it seldom works correctly, and will rarely remotely unlock or lock the car, although it is somewhat better at locking than unlocking. Reaching for the door handle normally works okay.

    Our other key (I bought the car used, with only one key) works fine.

    So, what's the problem? One of the following?

    1. The smart key is defective.
    2. The battery is already dying, at two months of age.
    3. The programming job was botched somehow.
    4. Something else?

    I should also mention that I replaced the aux battery a few days ago, but I can't say the behavior of the key was different following the change. Maybe it's a bit worse now. I used a keep alive power source during the battery replacement to prevent problems with the radio or power windows.

    Any ideas?
     
    #1 snijd, Oct 27, 2008
  2. rigormortis

    rigormortis Active Member

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    5. you are keeping it in the same pocket as a cellular phone or near one
     
    #2 rigormortis, Oct 28, 2008
  3. snijd

    snijd DIY or die

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    Unfortunately, the key doesn't work, even without a cell phone nearby. And now, the car doesn't work so well either, my son having been sideswiped by a bus. Well, it drives just fine, but they're going to replace the LR quarter panel, rear bumper, and wheel.
     
    #3 snijd, Oct 28, 2008
  4. rigormortis

    rigormortis Active Member

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    isn't that where one of the smart key antennas are? make sure they replace that, heh
     
    #4 rigormortis, Oct 29, 2008
  5. kenmce

    kenmce High Voltage Member

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    1. The smart key is defective.
    I'm leaning towards this one.

    2. The battery is already dying, at two months of age.
    Unlikely. They should be good for years.

    3. The programming job was botched somehow.
    The immobilizer should do the same thing with the same fob every time. If the immobilizer was flakey I'd expect it to be equally flakey with every fob. Can you swap the new fob for another one?

    Rigormortis:
    isn't that where one of the smart key antennas are? make sure they replace that

    If the antenna is that small flat plastic rectangle, then it is inside the car in front of the trunk, not in a fender or bumper.
     
    #5 kenmce, Nov 2, 2008
  6. snijd

    snijd DIY or die

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    I just replaced the key battery with the only one I had handy--out of another smart key. Now it works fine. The battery out of my 'new' smart key, purchased about 3 months ago, showed only 2.80 volts on my dvm--and evidently was already tired out.
     
    #6 snijd, Nov 13, 2008
  7. warrior

    warrior New Member

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    Dealer says change battery every year in smart key Is he right?
     
    #7 warrior, Nov 13, 2008
  8. rigormortis

    rigormortis Active Member

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    Can you swap the new fob for another one?

    Rigormortis:
    isn't that where one of the smart key antennas are? make sure they replace that

    If the antenna is that small flat plastic rectangle, then it is inside the car in front of the trunk, not in a fender or bumper.[/QUOTE]

    there are sensors in the fenders, doors or bumpers, to detect if the key is outside.... i think there is like 4 or 5 something
    sensors scattered around the car


    try locking your keys in your car on the drivers seat. if you press the lock button on the door and leave the key in each of the detection zones, you can rule out antennas or a problem with the key, heh

    keep a window rolled down

    (use the lock tab or power door lock to lock the car, pressing the remote control lock button is not valid for this test)
     
    #8 rigormortis, Nov 14, 2008
  9. snijd

    snijd DIY or die

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    If I was unclear, the problem is solved. New battery fixed the key. I just didn't expect the battery to be dead after only three months--and it began acting weak after only a month or so. Thought those lithium batteries had a longer shelf life.
     
    #9 snijd, Nov 14, 2008
  10. snengnr

    snengnr New Member

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    where'd u get the smart key from. I also bought a used Prius, and I want the smart key, but I only have a FOB key right now. And how much dis u pay for urs (please provide a breakdown of the actual cost of the key and the Toyota charge of installing it) thanx!
     
    #10 snengnr, Nov 14, 2008
  11. snijd

    snijd DIY or die

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    I'm assuming yours came with SKS. Got a new key from Conicelli Toyota--$120 sticks in my brain, but I forget the exact price. Got another off eBay for something like $55. Just make sure you get one with the silver Toyota emblem. Model number B31EG, I believe. Fee for programming varies, but most places want $100 now. You'll also need to order a key blank from Toyota. Most any hardware store can make a copy from an original.
     
    #11 snijd, Nov 14, 2008
  12. bruceha_2000

    bruceha_2000 Senior Member

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    Only if the dealer sells them and only if s/he is looking to take you for extra money. The battery should last about 4 years and that is if it is a SmartKey fob which sends out 'here I am' signals constantly. Should last longer in a non SKS fob. If you, or a friend, has a multimeter, you can check the voltage of the fob annually instead of throwing away a 3/4 good battery.

    It is a VERY standard battery, you can get them at Radio Shack (and I think I read WalMart), probably a lot of other places too and I'm sure for less than a dealer would charge (if they carry them). The battery number is printed on the battery cover, no need to get out the teeny tiny Phillips screwdriver before you get a new battery.
     
    #12 bruceha_2000, Nov 14, 2008
  13. snijd

    snijd DIY or die

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    It uses a CR2032 lithium battery.
     
    #13 snijd, Nov 14, 2008
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