TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker or making a Paypal contribution here: paypal.me/SupportTMC

Leave key fob in car, exit car, close door, then can't get back into car!

Discussion in 'Model S: User Interface' started by ecarfan, Aug 7, 2014.

  1. ecarfan

    ecarfan Well-Known Member

    Joined:
    Sep 21, 2013
    Messages:
    10,326
    Location:
    San Mateo, CA
    #1 ecarfan, Aug 7, 2014
    Last edited: Aug 7, 2014
    I've been on TMC for nearly a year now and don't recall reading about the issue I am about to describe, but maybe I missed it. Here is what happened to me today:

    I was in Monterey CA headed back home to San Mateo (near S.F.) and stopped at the Gilroy SC for a brief charge. I was there for about 15 minutes charging at 115kW and decided I had plenty of range to get home. I exited the car and shut the door, my key fob was in my shoulder bag on the passenger seat with my wallet, iPhone and iPad, in the same position it had been for the entire drive. I detached the charging cable, hung it up, and went to get back in the car. The handles had already retracted and they did not open when I applied pressure to them. None of the handles would open. I was mysteriously locked out of my car with the key fob on the passenger seat. It was not blocked by the iPad or iPhone in the bag, it was just below the upper surface of the bag. After about a minute of trying to open the door handles without success I decided to try to open the trunk. It opened, and then all the door handles extended and I got back in the car and drove home without incident. I decided it was likely just a freak occurrence, as clearly the car was detecting the fob since when I got in I could drive it.

    At home I got out of the car and without thinking about it again left my shoulder bag on the passenger seat with the fob inside and closed the door. I often do that because it is easier to retrieve the bag by going around an opening the passenger side door which is nearer the front door to my house as the wall of my house is very close to the drivers side of the car. I plugged in my HPWC cable, went around to the passenger side and again noticed that the door handles had retracted. It seems to me that they usually don't retract so quickly. Again none of the door handles would respond to pressure and open. I tried to open the trunk but it would not open. I tried several times. No luck. So I retrieved my spare house key from its hiding place outside my house, went inside to call my spouse to ask her to use her iPhone app to unlock the car, except she was out hiking with some friends and I could not reach her. After several more attempts to get the door handles to respond to me, I again tried the trunk and it opened and then the car unlocked so I could retrieve my shoulder bag with key fob.

    I called Tesla Service. They said they would have someone look at the car's logs and let me know if they found anything amiss, but in the meantime suggested that it was possible the fob battery was weak so the car did not detect it. That doesn't make sense to me: I have had the car for less than 8 months and the car did eventually unlock by me opening the trunk so the car must have sensed the fob. I have since tried using the fob to open the car and it behaves normally, with the handles extending as I approach the car.

    Regardless, I went out and bought two new batteries. I removed the batteries from both my fobs and measured their voltage, my fob was 2.99V and my wife's fob was 3.02V. The two new batteries I bought tested at 3.12V and 3.16V. A small difference between the old and the new batteries, but I am not convinced the original battery in my fob was the explanation for the problem I experienced.

    I went ahead and installed the new batteries in both fobs just in case. I'm interested in hearing from others who have experienced the issue I have described.
     
  2. martinwinlow

    martinwinlow Member

    Joined:
    Jun 18, 2012
    Messages:
    324
    Location:
    Herts, UK
    Perhaps there is a possible issue with the EMF from the nearby iPhone/iPad blocking or upsetting the fob-to-car 'conversation'… especially if a text was coming in and the iphone transmit power was at a peak… or something? MW
     
  3. J1mbo

    J1mbo Member

    Joined:
    Aug 20, 2013
    Messages:
    610
    Location:
    UK
    Maybe something was pressing on the top of the key, just enough to get it to activate..?
     
  4. Zythryn

    Zythryn MS 70D, MX 90D

    Joined:
    Mar 18, 2009
    Messages:
    1,660
    Location:
    Minnesota
    iPhones can interfere with the key fobs. The phone doesn't have to physically block the path, it just has to be nearby.
    My guess, without seeing the logs, is that it was just enough interference to allow a signal through intermittently.

    I always have my key fob in my pocket, so I have never experienced the issue you are speaking of.
     
  5. NigelM

    NigelM Recovering Member

    Joined:
    Apr 3, 2011
    Messages:
    13,257
    Location:
    Sarasota, FL
    I learned back in 2012 that having the keyfob and iPhone in the same pocket meant doors often wouldn't work and/or car wouldn't start up. Put them close together and there's often some random "noise" from the phone that upsets the fob communication.
     
  6. rdrcrmatt

    rdrcrmatt Member

    Joined:
    Jun 27, 2013
    Messages:
    551
    Location:
    Milwaukee

    I was just going to say something similar but I hadn't confirmed it yet. thanks for bringing it up! I often keep my phone and key in the same pocket and have intermittent issues. I'll try another plan.
     
  7. ecarfan

    ecarfan Well-Known Member

    Joined:
    Sep 21, 2013
    Messages:
    10,326
    Location:
    San Mateo, CA
  8. ecarfan

    ecarfan Well-Known Member

    Joined:
    Sep 21, 2013
    Messages:
    10,326
    Location:
    San Mateo, CA
    Thanks, but nothing was resting on top of the fob except the nylon fabric of the bag, and it doesn't put much pressure on the fob, which has to be pressed quite forcefully to work, in my experience.
     
  9. ecarfan

    ecarfan Well-Known Member

    Joined:
    Sep 21, 2013
    Messages:
    10,326
    Location:
    San Mateo, CA
    I have occasionally had my fob and iPhone in the same pocket such that the phone was between the fob and the car and of course then the phone blocked transmissions between the car and the fob.
     
  10. Ssssly

    Ssssly Member

    Joined:
    Feb 21, 2014
    Messages:
    100
    Location:
    Orlando
    So the moral of this situation is don't leave your fob and phone in the car and close the door?

    OP - Would you be willing to test out the theory that the phone/ipad caused the issue?

    This might help others.

    I'd also be interested if you could re-test the conditions with the new FOB batteries.
     
  11. apacheguy

    apacheguy Sig 255, VIN 320

    Joined:
    Oct 21, 2012
    Messages:
    3,705
    Location:
    So Cal
    @ecarfan - I had the exact same experience you describe. I talked to my service manager over the phone about it and he said it was because the car sensed the fob was located inside the car and had correctly locked the doors. I'm not sure about this new "feature" because there have definitely been several other times that I've left the fob in the car and haven't been locked out. Add it to the long list of 5.12 bugs?
     
  12. ecarfan

    ecarfan Well-Known Member

    Joined:
    Sep 21, 2013
    Messages:
    10,326
    Location:
    San Mateo, CA
    I'm on 5.9. Should have mentioned that in my OP.

    But I don't understand your service manager saying "the car sensed the fob was located inside the car and had correctly locked the doors". In that situation the car should NOT lock the doors because locking the doors locks the driver out of the car without the fob being in their possession.

    And I will be doing some more testing now that I have installed new batteries in my fob, testing when my wife is home and I have access to her fob.
     
  13. tom66

    tom66 Member

    Joined:
    Dec 17, 2013
    Messages:
    622
    Location:
    United Kingdom
    One thing of note - a coin cell at 3.0V is possibly very dead. The failure mechanism of a coin cell is to increase series resistance, far before terminal voltage drops, the effect of this is when the fob tries to draw current, the battery voltage will collapse. You need a tester which applies a standard load of about 30mA to the cell to be able to estimate the capacity.
     
  14. ElSupreme

    ElSupreme Model S 03182

    Joined:
    Jan 13, 2012
    Messages:
    4,279
    Location:
    Atlanta, GA
    I've had this situation happen to me as well. 8 months on a keyfob battery seems like a lot in my experience. I swap mine every 6 months or less. You can buy 20 on amazon for about $8 shipped prime for free.

    When you press the trunk button I think the car sends a signal out, and the fob responds. I rescued myself from locking the key in the car this way as well.
     
  15. Gizmotoy

    Gizmotoy Active Member

    Joined:
    Sep 16, 2013
    Messages:
    3,132
    Location:
    Bay Area, CA
    I've had all kinds of similar behavior with my car in our parking garage, which contains a cellular repeater. Handles refusing to present when the key is near, no proximity unlocking, all kinds of weird charging behavior. I've had the car since November and I didn't know until a few weeks ago that our instrument cluster had a charging indicator that comes up after you plug in. I'd seen pictures of it online previously, but thought it was removed in a later software update. After Tesla sent a tech out to visit my car in the garage and personally observe its shenanigans, I was put on the short list for a new Body Control Module that was revised with additional shielding. Once they installed that all of my problems vanished.

    Anyway, my point is that RF interference can do all kinds of unusual stuff to the car. If your phone was nearby the key, who knows what weirdness it may have been causing.
     
  16. ecarfan

    ecarfan Well-Known Member

    Joined:
    Sep 21, 2013
    Messages:
    10,326
    Location:
    San Mateo, CA
    #16 ecarfan, Aug 8, 2014
    Last edited: Aug 9, 2014
    Did some testing today with inconclusive results.

    With a new battery in fob (tested at 3.16V) I left the fob on the passenger seat, let the door handles retract, waited 30 seconds and was able to touch the handles and get into the car.

    With fob in my shoulder bag right next to a powered on iPhone and with my iPad in the bag as well, did the same test and was able to get into the car.

    With my old battery in the fob (which tested yesterday at 2.99V and today at 3.0V) I repeated both tests and both times was able to get into the car.

    So I cannot draw any firm conclusions.

    Excellent point, thanks. Possibly my fob with the original (now almost 8 month old battery) is right on the borderline of usability, and in some circumstances may not be functional.
     

Share This Page