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Question regarding manually using the FOB to start the car

Discussion in 'Gen 4 Prius Main Forum' started by sylvaing, Aug 14, 2023.

  1. sylvaing

    sylvaing Senior Member

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    I know that when the battery is dead, you can put the FOB against the Start button to start the car, but is this menthod fully passive? I mean, if I drop my key in the ocean and it stays there for a few hours before I notice it, will it still work (that's just an example, don't get hung up on it)? I know I would be able to open the door with the key but that's not good if I can't start the car. My previous "Push Start" vehicles had a mean to insert the key in a key slot then press Start, so fully manual. This one, looks like it uses NFC (since I don't even need to press Start, just push the brakes and put the FOB on top of the Start button) so electronics involved.
     
    #1 sylvaing, Aug 14, 2023
  2. bisco

    bisco cookie crumbler

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    there is an rfid chip in the fob case (unless they've changed it) i guess the question is, is it waterproof, etc.

    can't find anything online specifically related to the fob chip.
     
    #2 bisco, Aug 14, 2023
    Last edited: Aug 14, 2023
  3. kevinwhite

    kevinwhite Active Member

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    Most cars built in the last 20 years have an immobilizer that is activated by a chip in the key using NFC to communicate with the engine controller. This applies even if the car doesn't have push-button start. It doesn't require a battery in the key.

    The Gen 4 Prius doesn't have a slot to plug the key into like the Gen 2 did but it works exactly the same, it just requires proximity. It will work even if the battery is flat.

    kevin
     
    #3 kevinwhite, Aug 14, 2023
  4. sylvaing

    sylvaing Senior Member

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    Thanks. Do you know if it's waterproof? On a key, the NFC is within the plastic part of the key and no water can get into it. Not sure if the same can be said about the FOB internals.
     
    #4 sylvaing, Aug 14, 2023
  5. bisco

    bisco cookie crumbler

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    water can definitely penetrate the fob, i just don't know if it will penetrate the chip
     
    #5 bisco, Aug 14, 2023
  6. sylvaing

    sylvaing Senior Member

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    Yeah, FOB are too expensive to try and experiment with it lol.
     
    #6 sylvaing, Aug 14, 2023
    bisco likes this.
  7. FuelMiser

    FuelMiser Senior Member

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    Actually still you have to push the Start button after placing the fob over the button
     
    #7 FuelMiser, Aug 15, 2023
  8. sylvaing

    sylvaing Senior Member

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    No, I didn't when I tried it. I pushed the brake pedal, moved the FOB in front of the Start button and the car came alive.
     
    #8 sylvaing, Aug 15, 2023
  9. FuelMiser

    FuelMiser Senior Member

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    Note Step 4 in the procedure for my 2016 Hybrid. Perhaps the 2017 Prime operates differently.

    Screenshot 2023-08-16 at 3.17.10 AM.png
     
    #9 FuelMiser, Aug 16, 2023
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