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SKS Keyless Entry does not work Prius 2005

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by doctorman, Aug 5, 2020.

  1. doctorman

    doctorman Member

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    Have 2 FOBs that stopped working wirelessly , they work when I plug them in to turn the car on,
    The red LED on FOBs turn on when buttons pressed
    12v battery is checked and is good
    KEY SKS button under steering wheel checked multiple time, it is not that
    FOBS do not work even when placed directly on top of the power button, by driver side, passenger side and hatch.
    The only function that works on FOB now is driving the car by entering the FOB in the slot.

    both FOBS act the same so it is not the FOB.

    The only thing that recently happened is the windows left open when there was a bit of rain so the passenger and driver seat got a bit wet.

    No engine light issue.

    I have techstream to help with diagnostics but have not used it yet ..

    Would appreciate any help on this
     

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    #1 doctorman, Aug 5, 2020
    Last edited: Aug 5, 2020
  2. bisco

    bisco cookie crumbler

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    check the 12v health
     
  3. doctorman

    doctorman Member

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    checked, that is not the issue
     
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  4. bisco

    bisco cookie crumbler

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    maybe some moisture got into one of the antennae ecu's
     
  5. doctorman

    doctorman Member

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    the question is how do I proceed to diagnose and repair
     
  6. bisco

    bisco cookie crumbler

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    you can try hooking up tech stream, but idk if it will pick up any codes if therearen't any trouble lights. it's worth a shot
     
  7. dolj

    dolj Senior Member

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    When you say, "it's not that," do you mean the button is in the SKS enabled position which is the "out" position? The "in" position is SKS disabled. Just asking to be clear what your situation is, as your description of the problem sounds like the SKS is disabled.
     
  8. doctorman

    doctorman Member

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    tried both in and out
    whn it is out , meaning SKS enabled, pressing the start button without the key plugged in, turns on the yellow security light on dashboard meaning key not recognized

    so yeah the antenna is not picking up the key
    is it it one antenna?, is it just an easy swap or do I need programming
     
  9. doctorman

    doctorman Member

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    looking at the picture in post 1
    there is room oscillator and the door receiver on the passenger side
    considering it is an antenna issue and everything else works my money is on these two
    Any idea how to differentiate between which is the issue
     
  10. bisco

    bisco cookie crumbler

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    probably not without tech stream. there is one in the center console, iirc
     
  11. doctorman

    doctorman Member

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    Techstream read code B2775 under immobilizer
    resetting it did not make it come back immediately
    system still the same
    tried reading ACTIVE Data and tech stream crashes no matter what I do
    v13
     

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  12. bisco

    bisco cookie crumbler

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    techinfo.toyota.com
     
  13. doctorman

    doctorman Member

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    seams like the transponder ECU
    also known as the Immobilizer ECU located on the right side of the steering wheel in the dash
    Toyota part number 89780-47030
    might be the issue, or could be a connection issue.
    if that does not solve it, then it is the certification ECU which I still do not know the part number for it.
     
  14. bisco

    bisco cookie crumbler

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    electrical issues are often the toughest to diagnose
     
  15. WilDavis

    WilDavis Senior Member

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    I bought my 2009 Gen II in 2014 and both occasions when I've had a problem with the SKS, it has turned out to be the batteries in the fob. hope this helps - Good luck! - Wil
     
  16. doctorman

    doctorman Member

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    @Elektroingenieur would appreciate your insight on this please

     
  17. doctorman

    doctorman Member

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    10 days later in the heat of summer the car went back to normal
    My guess is some water got into the part of the SKS systems and evaporated
    hopefully it will stay that way
     
  18. thejaycan

    thejaycan Junior Member

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    Question for you @doctorman, I seem to have the same symptoms you do. When your fobs weren't working with the keyless entry/start, did the unlock/lock/panic buttons on the fob work or did that not work either? (Those don't work for me).

    I've been fighting this issue for a bit, the warmer temperature did get it working again for me for a while (a month or so) but now the problem is back.

    I did a really interesting test but the results are confusing. I started the car with the key in the slot, but not all the way in where it locked, just enough to start it and pulled the key out. With the car in ready mode I took the key outside the car and closed the door. The car beeped three times. I then opened the door, put the fob on the driver's seat and closed the door. No beeps. So the car is detecting the fob, but why doesn't it work to start or smart entry or even lock/unlock with the buttons on the fob? Head scratching over here.
     
  19. doctorman

    doctorman Member

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    I bet there is a rusty dirty connection in the ECU or its connection, if its happening again maybe just change it and get it over with , it is a cheap part on ebay , but again it could be anything else

    my button on the fOB did not do anything when it was not working
     
  20. thejaycan

    thejaycan Junior Member

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    I fixed it today, my Door Control Receiver (p/n 89741) went bad. I fired up Techstream and was getting Code Mismatch and time out errors from the key so I suspected either the harness, the Door Control Receiver, or the Certification/SmartKey ECU. I didn't have any good reason to suspect the harness and the Door Control Receiver is way easier to get to versus the Certification ECU (taking the whole dash apart) so I started there. Bought a used one from ahparts and put it in and problem solved.

    Hope these threads help other people with SKS problems.
     
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