Smart key not recognized

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by bentle, Dec 29, 2017.

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  1. bentle

    bentle New Member

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    2010 Prius: The "key battery low" message popped up. I replaced the battery. The fob is blinking and will lock/unlock doors. The interior/dash lights are lighting correctly. I hear the vacuum pump kick on when I hit the brakes, but the power button doesn't turn green.
    Brand new Optima battery, checked smart key fuses. Any advice?
     
    #1 bentle, Dec 29, 2017
  2. bisco

    bisco cookie crumbler

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    check the voltage of the brand new optima battery, and the connections for cleanliness and tightness. don't forget the neg to ground.
     
    #2 bisco, Dec 29, 2017
  3. Johnny Cakes

    Johnny Cakes Senior Member

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    Have you tried placing the key next to the START button? How sure are you that the battery that you replaced in the key FOB was good? Sometimes a "new" battery purchased has been sitting around for years.
     
    #3 Johnny Cakes, Dec 29, 2017
  4. bentle

    bentle New Member

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    Well, the battery is about two months old and measuring 12.5V. The connections all look clean and tight.
    I’ve tried holding the fob up to the start button. Two new batteries—and the fob is flashing, the remote buttons working, so I feel the batteries are good.
     
    #4 bentle, Dec 30, 2017
  5. bentle

    bentle New Member

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    And it won’t jump start...I would think that would bypass the 12V battery entirely?
     
    #5 bentle, Dec 30, 2017
  6. Rebound

    Rebound Senior Member

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    This just began happening to me, intermittently. I’ve replaced both fob batteries and I hope that does it. On last failure, car would not start until I used remote to lock/unlock doors, then all was good.
     
    #6 Rebound, Dec 30, 2017
  7. bisco

    bisco cookie crumbler

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    how did you measure the 12v?
     
    #7 bisco, Dec 30, 2017
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