Key fob in '09 Prius doesn't work

Discussion in 'Gen 2 Prius Main Forum' started by tundrwd, Mar 14, 2013.

  1. tundrwd

    tundrwd Member

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    Started having problems with one of the key fobs for my '09 Prius about a year ago. Battery change, perked up a bit, but then started malfunctioning. At first, wouldn't unlock car doors, then wouldn't start car. Will do so if insert into the fob receptacle, but not remotely.

    I'm trying again to revive it, since it only lasted 4-5 months before. Won't unlock car doors again, etc. Unlock button does not appear to be stuck - you can feel it "clicking" when you press it, so it doesn't appear to be the stuck button problem.

    What I'm wondering is - if the battery really runs down (the thing was in my pocket, and kept having buttons accidentally pressed at times), can the car lose the "programming" for that key fob? Will an attempted reprogramming/repairing work? Or is it just dead?
     
  2. desmondlee

    desmondlee Member

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    does it do the same thing with the other fob? Just making sure it is limited to the one you are using
     
  3. tundrwd

    tundrwd Member

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    Other one works - but range seems diminished for all functions (door lock/unlock, starting). Having key in a pocket will sometimes seem to block the signal, and I have to move it around, or take it out a moment to get it to work.

    So - one doesn't work, the other works with diminished range (even after battery change).
     
  4. desmondlee

    desmondlee Member

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    by any chance, is there a cell phone near the fob?
    when I had the iPhone 3 & 4 and the fob was right next to it, most of the the fob did not work until I moved the fob out of the way.
    iPhone 2 and 5 does not seem to have that problem
     
  5. tundrwd

    tundrwd Member

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    Sometimes - but not always. I've tried the non-functioning one all by it's lonesome, nothing anywhere near it at all. That fob does not work.
     
  6. Eclipse1701d

    Eclipse1701d Prius Enthusiast

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    If you 12 Volt battery is original, or failing, the behavior you described will occur. My 07 did the same thing and the battery began to fail about six weeks later. That is a warning sign. If you let it go longer, the 12 volt will fail and you'll have to do some real wiggling around to get the hatch released from the inside to change the battery.

    Here is a link to test the battery... Many folks on priuschat opt for the Optima Replacement and do the switch themselves. Please run the test and let us know what you find!

    Entering Maintenance Mode (aka 12V Battery Check) without Switching Headlights ON/OFF | PriusChat
     
  7. dorunron

    dorunron Senior Member

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    I don't think that test method will work on the '09. The screen is a little different than the one that is pictured. I tried that method several times on our '09 and could never make it work.

    However, this one does. When I flash the lights, I don't turn the headlights on, I simply cycle the parking lights.

    Weird stuff happening? MPGs dropping? Test The Battery | PriusChat

    Hope this helps ya.
     
  8. tundrwd

    tundrwd Member

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    Ok - tested battery, and it was failing. 4.5 yrs old - so that's to be expected. It has now been replaced, and the working fob now has better communication distance for locking/unlocking doors.

    However - the original question still remains - what about the non-functioning fob (which still doesn't function after battery replacement)? Dead or reprogram or ... ?
     
  9. Eclipse1701d

    Eclipse1701d Prius Enthusiast

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    Battery in the FOB is most likely dead. Replace and enjoy! No need for reprogramming...
     
  10. tundrwd

    tundrwd Member

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    Battery has been replaced with fresh battery - two of them to make sure. Still non-functional. Did that before posting.
     
  11. Eclipse1701d

    Eclipse1701d Prius Enthusiast

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    Does the button on the FOB light when you press it? If not, maybe the battery is not seated properly or the rubber seal is impeding contact? If it's original and has a good battery, you shouldn't have to reprogram anything...
     
  12. tundrwd

    tundrwd Member

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    No light.
     
  13. tundrwd

    tundrwd Member

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    Looking at it closer, it appears that the alarm button on the keyfob is stuck. Won't click, etc. The lock/unlock works ok - but the alarm button seems to be stuck. That was one issue I had with the fob originally - alarm kept going off. Is there something that can be sprayed into the unit to clean the button, without shorting it out?

    I did pop the alarm button out - doesn't seem glued, etc. Now the alarm button (white button inside works), and the fob lights up now when pushing buttons. (I'm sure the battery I put in a couple days ago needs replacing. Button down caused a "dead short", so I'm sure battery life has been compromised).

    I used to have some old TV Tuner cleaner - but that stuff is long gone....
     
  14. dorunron

    dorunron Senior Member

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    I have the same situation as you, alarm button popped off. I don't know how long the fob will work like that. Mine has been that way for about a year now and is still chugging along. Try putting in a new battery and go from there.

    It sounds like you have found the problem.

    I am not aware of any lube you can use on it, if you want to risk it you might try to find some electronic contact cleaner and try that. I think as long as you keep the fob relatively clean and dry you should be Ok.

    Good luck to you.
     
  15. HTMLSpinnr

    HTMLSpinnr Moderator
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    In the absence of electronics cleaner, some 91% Isopropyl alcohol on a cotton swab will suffice. I've cleaned many a mouse, keyboard, remote control and car remote with it w/o any lasting consequences. The amount of remaining water is negligible (at least in my dry climate). Just make sure there is no power (remove the battery) before attempting the cleaning.
     
  16. 2009Prius

    2009Prius A Wimpy DIYer

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    After cleaning and everything inside thoroughly dried, maybe you can use some clear silicone to cover up the alarm button to provide moisture barrier and still allow enough flexibility for you to push the button.
     
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