Key Fob Not Working

[GKwey]

This afternoon I took my car to Mt. Wilson for a pleasure ride. Leaving home with 80% charge (daily full charge), arriving at 50% charge. Both car and phone lost internet connection there. Heavy fog turned into light rain. Spent two hours in observatory. When I was ready to leave, the doors won't pop when I got close. Touching the door handle won't pop it out. I started panic: It shouldn't lose all the battery juice in just two hours, even though it's raining it's not that cold. Hitting key fob for opening door, frunk and truck; none worked. Took a ride back down to La Canada and call roadside assistance from McDonald's. They can connect to car and remotely open the door but I need to be there. I was also told if someone else has the app, they can open the door for me as well. It's getting dark, so I took a Lyft home and plan to take care of it tomorrow. Just now installed the Tesla app on wife's iPad, so she can help me remotely open the door as backup tomorrow in addition to the assistance from Tesla.

I need to understand why this is happening so it won't happen again. I will research into this topic, but hopeful I may get some insight from you guys out there. Why the key fob is not working? Is it because lack of cellular connection for either or both of car and phone? How to prevent this inconvenient breakdown from happening again in future? I recall now that I once read about putting key fob near windshield if everything else failed. Too bad I did not think of this and gave it a try.

I was able to connect phone app with the car at home, even though according roadside assistance staff the signal from car is in and out not steady. It does show car still has 50% charge. Key fob should have enough battery since I only received the car for little over 5 weeks ago.

 

[TES-E]

I had a similar problem, but not as dramatic. I went to the local store 10 minutes from home. When I came back out to the car, I went through the same thing you did... nothing worked. I was mentally going through my list of who to call to come get me when I remembered that I had my phone app. It connected to the car, and I unlocked it. Once in, I told it to start, and it did. Drove home, but fob still did not work. Battery replacement did noghing. My wife's fob did, so I knew the car was ok. Called the service center, and first chance I got, I went in and they replaced the fob. All is well.

 

[GKwey]

I got this link after google the problem:
Important tip for owners regarding key FOB signal interference | Tesla Motors
So the interference between key fob and car appears to be caused by cell towers (Mt. Wilson does have a lot) interference. Tesla should have put out warning staying away from cell towers.

 

[David29]

I have had problems with key fob twice at the same store, which is an electronics store that also happens to be quite close to three television transmission towers. So my working theory is that either the TV signals interfere, or the store has ham radio equipment operating (it does sell such gear) and that is interfering. Both times, it has resumed working after a few tries, so the signal strength of whatever is interfering must vary. But learning the trick of placing fob near the passenger side wiper also seems like good insurance...

 

[BertL]

OP, sorry to hear about this. I'd be slightly panic'd as well in your circumstance.

Next time, if my Tesla App were also unavailable (you have to have cell data service for that option to work on both your phone and by the MS itself), I'd try the procedure on p7 of your owner's manual to unlock MS when the FOB doesn't work. It basically requires you place your FOB on the front windshield above and just left of where the passenger wiper arm goes under the hood. Press the door handle and it should unlock. If not, reposition the FOB slightly and try again. Repeat until it works. (To convince myself after I took delivery, I tried the procedure in my garage by taking the battery out of my FOB, and it worked after a few tries getting it in the right location.)

Simply as a parallel POV: I've read similar challenges with outside sources like cell towers, ham radios, etc likely interfering with FOBs in both Lexus and MBZ over the years. FOBs in the same pocket or purse next to a cellphone can also cause the vehicle to not recognize the FOB. Assuming your FOB battery is still good, I suspect this is more of a challenge with common radio technologies being used, than it is a specific Tesla problem. The big difference IMHO is that my previous Lexus and MBZ FOBs had a physical driver-side key built-in, so if all-else failed, one could always physically get into the vehicle the traditional way. With our forward-thinking MS of course, that isn't an option and the FOB-on-the-windshield trick is necessary.