Replaced FOB battery, light flashes, but still can't open the car....

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by mjm114, Aug 10, 2011.

  1. mjm114

    mjm114 New Member

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    Quick question, my wife wasn't able to open our '04 Prius with the FOB. I replaced the battery, and the FOB started flashing, which I'm assuming means that the new battery is working properly. However, after I put the FOB back together, the lock/unlock bottons still don't work. I can still manually open the car with the attached key and start the car with the FOB, but I was wondering if there's still a problem.

    I did all the steps on the knowlege base to reprogram the FOB so that it will lock & unlock, but because the light doesn't flash when I hold both the lock & unlock bottons (one of the last steps) nothing happens because it appears the FOB isn't sending a signal.

    Any suggestions? BTW- it is a non-SKS Prius.
     
    #1 mjm114, Aug 10, 2011
  2. northwichita

    northwichita .

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    I did all the steps on the knowlege base to reprogram the FOB so that it will lock & unlock, but because the light doesn't flash when I hold both the lock & unlock bottons (one of the last steps) nothing happens because it appears the FOB isn't sending a signal.


    Is this a replacement FOB? Once programmed to a car, changing the battery in the FOB shouldn't effect it.

    One quick test I know of for the FOB in general, I was in an O'Reilly's parts store and saw that they had a test device where when activated it could detect if your remote is sending a signal. It's worth knowing that the FOB itself is functioning.
     
    #2 northwichita, Aug 11, 2011
  3. mjm114

    mjm114 New Member

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    No, this isn't a replacement, it's one of the FOBs that came with the car. It's in pretty bad shape, so I'm assuming there must be wrong with the transmitter. It's just wierd that the light blinks after I change the battery but doesn't blink when I reprogram it.

    The reason I changed the batter in the first place was because the lock/unlock didn't work a few times.
     
    #3 mjm114, Aug 11, 2011
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Pls note that the immobilizer (and Smart, if applicable) ECUs are programmed, not the fob. Hence that should have no effect on the fob. Suggest you may want to verify the condition of the fob battery contacts. Maybe they are intermittent.
     
    #4 Patrick Wong, Aug 11, 2011
  5. wrexed03

    wrexed03 New Member

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    I suspect one of your buttons is stuck down this is why it constantly flashing.
    You will need to take the top part apart where the buttons are and make sure they work correctly.
    Happened to me after dropping my keys and one of the buttons got stuck as if it was getting pressed. There is a post somewhere on the forum with instructions how to get the top section apart.
    Hope this helps.
     
    #5 wrexed03, Aug 11, 2011
  6. mjm114

    mjm114 New Member

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    Turns out I think the FOB was broken...got a new one on Ebay and was able to reprogram w/out any problems. Thanks for everyone's help.
     
    #6 mjm114, Aug 18, 2011
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