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FOB dead after 1 week. Where is the RFID unlock actually located?

Discussion in 'Model X: User Interface' started by RossRAllen, Feb 1, 2016.

  1. RossRAllen

    RossRAllen Member

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    My primary FOB is dead after one week. I may have left it overnight near the Model X, and (according to some) that drains the FOB battery with repeated interrogations between the FOB and the car. (I didn't know the FOB receives and responds, I though it was a transmit-only device.)

    My reserve FOB works fine, just ordered 3 extra batteries from Amazon. My iPhone Tesla App also unlocks the car. Good for a Plan B entry and drive away IF there's LTE reception, I suppose.

    But, I cannot unlock or start the car with the dead FOB near the base of the pillar between the driver's door and the Falcon Wing Door as specified in the manual. Note that the manual has a figure left over from Model S. Also, the car would not recognize the dead FOB when placed below the 12VDC adapter.

    Does anyone know where the RFID unlock is on the Model X? Have you used it? And, the drive-away position for a dead FOB?
     
  2. CHG-ON

    CHG-ON Still in love after all these miles

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    On an S it is at the base of the windscreen on the passenger side. At least that's what the manual says. You might want to try that. I never have.
     
  3. Lloyd

    Lloyd Active Member

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    it is actually at the end of the dash under the end panel against the door on each side, but the best place for transmission is as above.
     
  4. deonb

    deonb Active Member

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    Is it really RFID? I thought it was a myth that these fobs contain RFID transponders. So are you guys actually able to remove the battery and have the fob still work?
     
  5. pvogel

    pvogel Member

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    They are NOT RFID. The X is Bluetooth Smart. RFID only works in extremely close proximity. I suppose it could be a secondary backup
     
  6. RossRAllen

    RossRAllen Member

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    The fob is Bluetooth and it has an RFID CHIP serving as backup if the battery is dead. That's why the short range.

    I couldn't get the "dead" fob to work anywhere along the base of the windshield or at the base of the pillar between the front door and the falcon wing doors.
     
  7. deonb

    deonb Active Member

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    Do you have that on authority of any source except for a DS?

    DS's has been touting the 'The key Fob has an RFID chip' line since before the Model S release but nobody has ever found any evidence of it, nor is it mentioned in any Model S user manual.

    Of course the X may have changed this, but I wouldn't believe it unless you've seen it in the user manual.
     
  8. RossRAllen

    RossRAllen Member

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    I'm inferring that there is an RFID chip in the fob because it must be placed in close proximity to a sensor. If the battery is dead, the Bluetooth won't work so this is a passive system. I could not find an explicit reference to RFID in the Model X manual, so I must assume that there is something in the key that works in proximity to a "key antenna" when the battery is dead. The most-likely thing is an RFID chip IMHO.

    On Page 9 of the Model X Owner's manual, there's a diagram that shows five "key antennas". Since I have a dead fob, I'll try each one although the manual says to press the driver's door handle at the same time the fob is in position (#1).
     
  9. pvogel

    pvogel Member

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    Quick way to test -- I'll set up an Arduino with both RFID reader types and see if I get a reading off the fobs.

    Peter+
     
  10. vandacca

    vandacca Active Member

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    It's entirely possible that there is no RFID chip in the FOB and Tesla was thinking that if the battery is quite low and the FOB is not generating a strong signal, putting the FOB close to the antenna might be enough to pick up a weak signal. If the FOB is completely dead, putting it next to any antenna won't help at all.

    I'm curious to see Peter's Arduino's test results.
     
  11. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

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    I was not able to detect an RFID chip in my Model S fob with any of the scanners that I have.

    I suspect the reason you are told to place it in a specific location is to maximize the reception for a very weak battery.
     
  12. FarmerDave

    FarmerDave Member

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    I have a bit of an issue that may be related to battery strength. When I use "Summon" I have to be in just the right place with the fob or else the Tesla App says there was no communication with the fob. Even standing just to the side of the garage doesn't work. Would a new battery help? I've only had the car less than a week.
     
  13. RossRAllen

    RossRAllen Member

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    FarmerDave - I changed the battery and the fob works fine. The battery is supposed to last a year. Best deal is to buy a 3 or 4 pack from Amazon.
    Try your other fob and see if it works. Keep one away from the car so it won't be drained if there's a bilateral interaction between car and fob. (I thought the fob was transmit only.)
    We are eagerly awaiting the results from pvogel's test...
     
  14. pvogel

    pvogel Member

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    I can set up a test probably this weekend. Does someone in the south bay area have a fob they want to loan to the effort? Since I don't have my X yet. :cursing:

    Peter+
     
  15. RossRAllen

    RossRAllen Member

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    Screen Shot 2016-02-03copy.png

    It's a little crazy that we have to resort to this level of research.

    pvogel - any chance that your measurement system is portable enough that you can identify the "key transmitters" around an X? See the figure above showing 5 points from the manual. #2 is the one cited in the manual for unlocking the driver's door with a dead battery in the fob.
     

    Attached Files:

  16. pvogel

    pvogel Member

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    Those indicators are for where the bluetooth antennae are, and any iPhone will help verify their location quite easily assuming they are using Bluetooth 4.0 (SMART/LE). The question on this thread is whether the fobs have a backup RFID chip (somewhere I saw some reference to a dead key being usable when placed in a cupholder). My little RFID readers are very portable, but they'll read an RFID chip, they won't detect the presence of another RFID reader.

    Peter+
     
  17. st50maint

    st50maint Member

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    i removed the battery from my FOB. I was then able to unlock and start my Model S by placing the FOB in the recommended locations.
     
  18. mknox

    mknox Well-Known Member

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    That is what I believe to be true as well.

    - - - Updated - - -

    Mine would not work at all when I tried this a while back. I wonder if there has been a change over time. I have a Feb 2013 build car.
     
  19. RossRAllen

    RossRAllen Member

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    From the latest Owner's Manual, it is at the base of the pillar between the front driver's and Falcon Wing door - all the way down by the mud guard. I though it might be more convenient at the height of the bottom of the driver's window. I haven't tried it yet, both fobs operating. Spare battery kept in the glove box. iPhone app provides Plan B unlocking assuming there's LTE or 3G reception where the vehicle is parked.
     
  20. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

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    My wife called me (while I'm on a business trip) to tell me that her Model X keyfob battery appears dead. It seems that for those whose cars spent more time than usual in the factory, the keys were kept with the cars and therefore drained the batteries faster than expected.
     

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