1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Making a new key fob?

Discussion in 'Gen 4 Prius Technical Discussion' started by Patric88, Aug 9, 2019.

  1. Patric88

    Patric88 Junior Member

    Joined:
    Jul 22, 2019
    34
    16
    23
    Location:
    Chicago
    Vehicle:
    2018 Prius Prime
    Model:
    Prime Premium
    Hi all, not sure if this is in the correct section.

    I opened up my key fob to replace the battery (2017 Prius 2) and I noticed the actual electrical components is like 1/3 the fob size. I don't use the panic function and I can live without the locking buttons because I have the door handle button. So what I'm thinking, is there a way to shorten the motherboard, remove the buttons and keep the key fob on me ? It should only be the size of 2-3 quarters stacked when done. I'd then keep this inside my wallet, so I'd never carry a key on me(house is wireless)

    Is this a valid idea?
     
    #1 Patric88, Aug 9, 2019
    Last edited: Aug 9, 2019
    Mambo Dave likes this.
  2. sam spade 2

    sam spade 2 Senior Member

    Joined:
    Mar 31, 2018
    7,035
    2,780
    0
    Location:
    USA
    Vehicle:
    2017 Prius c
    Model:
    Four
    Maybe. Probably.
    Or some other way to keep only the RFID function without the buttons or batteries.
    A locksmith who REALLY understands how it all works might be able to help.
    Forget talking to a Toyota shop.

    This should make for an interesting discussion here.

    My honest first reactions was:
    Not worth wasting your time and money to find out.
    Both could be much better spent on other really important things.
     
    Patric88 likes this.
  3. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    wow, why did they have to use such large case? more backward engineering from toyota.

    maybe you could slip it into a small vinyl pouch like a credit card holder or something.
     
    Patric88 likes this.
  4. t_newt

    t_newt Active Member

    Joined:
    May 27, 2018
    216
    240
    0
    Location:
    94087
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Plus
    It should work and I think it is a good idea--the FOB is a pretty bulky thing all the car companies are making us carry around.

    The only problem I see is where to put the emergency mechanical key that is hidden in the FOB. Maybe it can go on your keychain as a separate key.
     
    Patric88 likes this.
  5. Patric88

    Patric88 Junior Member

    Joined:
    Jul 22, 2019
    34
    16
    23
    Location:
    Chicago
    Vehicle:
    2018 Prius Prime
    Model:
    Prime Premium
    The emergency key will be hidden underneath the car via zip ties, or a very slim hide-a-key
     
    #5 Patric88, Aug 9, 2019
    Last edited: Aug 9, 2019
    bisco likes this.
  6. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    a few years ago, someone figured out how to make a lexus credit card fob work with prius.
     
    Mambo Dave likes this.
  7. Patric88

    Patric88 Junior Member

    Joined:
    Jul 22, 2019
    34
    16
    23
    Location:
    Chicago
    Vehicle:
    2018 Prius Prime
    Model:
    Prime Premium
    I'm not against some kind of device that works off nfc to unlock my car when my phone is present. I work in the sales field, my phone is always on me and always charged. So that's not a worry.
    Possible way to splice in a nfc proximity sensor and wire it into the RFID scanner?
     
  8. Patric88

    Patric88 Junior Member

    Joined:
    Jul 22, 2019
    34
    16
    23
    Location:
    Chicago
    Vehicle:
    2018 Prius Prime
    Model:
    Prime Premium

    Didn't know these existed, I'll order one and a RFID editing machine and I'll get to work on this. When I'm off work, I'll look into the frequencies and such.
     
    bisco likes this.
  9. Cshigeok

    Cshigeok Junior Member

    Joined:
    May 20, 2016
    5
    1
    0
    Location:
    Hawaii
    Vehicle:
    2016 Prius
    Model:
    Four
    Following =)
     
  10. alanclarkeau

    alanclarkeau Senior Member

    Joined:
    Feb 24, 2016
    7,041
    7,580
    0
    Location:
    near Brisbane, Australia
    Vehicle:
    2016 Prius
    Model:
    N/A
    I think the reality is that they're much the same size as most on the market.

    It's got to be a balance of - big enough to not lose easily, big enough to be robust enough for tradespeople etc, big enough to be able to dismantle easily without a magnifying glass, big enough to hold a reasonable sized battery - and small enough to be reasonably portable. People lose Smart Phones!! A coin sized FOB - the manufacturers would love them because they'd be selling replacements much more often.

    I don't doubt they could be made smaller - but if it's going to have to be mounted on a key-ring, it's small enough.
     
  11. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    actually, it's much bigger than the past two generations, which seems odd, and less comfortable in the pocket. whereas lexus has a credit card type.
     
  12. alanclarkeau

    alanclarkeau Senior Member

    Joined:
    Feb 24, 2016
    7,041
    7,580
    0
    Location:
    near Brisbane, Australia
    Vehicle:
    2016 Prius
    Model:
    N/A
    Oh - mine is about the same as the FORD I had last. Better than a fixed key with a FOB built in like in the olden days - remember them :rolleyes:?

    The PRIUS has got 3 buttons as well as a built-in key, more than some, though now I think about it, the FORD had 3 buttons - one for the boot, but no emergency button.
     
  13. Elektroingenieur

    Elektroingenieur Senior Member

    Joined:
    Jan 8, 2017
    2,515
    3,253
    9
    Location:
    California
    Vehicle:
    2016 Prius
    Model:
    Three Touring
    Toyota’s answer is the Smart Key Box, but I have no idea how you’d get one without being a large fleet customer.
    I don’t think so. The RFID reader is in the power switch, but the allow/deny decision isn’t made there; the keys don’t have to be registered again if the switch is replaced. Instead, as Toyota explains in New Car Features (more info), the switch “Receives the ID code and transmits it to the certification ECU (smart key ECU assembly) when the key battery is too weak to respond to the tuner based on the signals from the room antennas.”
     
  14. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    mine has 4 buttons with the remote a/c
     
    alanclarkeau likes this.
  15. kithmo

    kithmo Couch Potato

    Joined:
    Apr 25, 2010
    2,404
    2,773
    47
    Location:
    South Yorkshire, UK
    Vehicle:
    2016 Prius
    Another solution would be to hang the key around your neck on a lanyard.
     
  16. alanclarkeau

    alanclarkeau Senior Member

    Joined:
    Feb 24, 2016
    7,041
    7,580
    0
    Location:
    near Brisbane, Australia
    Vehicle:
    2016 Prius
    Model:
    N/A
    I'm looking - but can only see 3 - but it's 1) early morning; and 2) a Public Holiday:
    upload_2019-10-7_10-0-0.png

    Oh - wait, there's more. There's a button to remove the REAL Key underneath.
     
    bisco likes this.
  17. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    i have a 2012 plug in prius :p
     
  18. alanclarkeau

    alanclarkeau Senior Member

    Joined:
    Feb 24, 2016
    7,041
    7,580
    0
    Location:
    near Brisbane, Australia
    Vehicle:
    2016 Prius
    Model:
    N/A
    Ahh - so they've downsized for Gen 4 - maybe weight reduction? Mine is 37 grams.
     
  19. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    upsized. mine is about 2/3 the size of yours. that's why i made the original comment
     
    alanclarkeau likes this.
  20. kithmo

    kithmo Couch Potato

    Joined:
    Apr 25, 2010
    2,404
    2,773
    47
    Location:
    South Yorkshire, UK
    Vehicle:
    2016 Prius
    alanclarkeau and bisco like this.