Key fob not working after battery replacement

[Ryan MF]

One of my MX key fobs stopped working this winter and the other key fob had a low battery warning so I went ahead and replaced both batteries. They were more than two years old.

After replacing the batteries neither fob worked. I ordered the same type of batteries and tried resetting them a few times. Today I took both keys to Tesla and they said they also could not get them to work and would order replacement keys.

This seems very strange that both fobs would completely stop working after a battery change? I suppose one could have died before but seems too coincidental. Has anyone experienced this or any ideas of how to bring them back to life?

 

[Sandiegodoug]

I had the same problem. One key fob went dead, replaced batteries, still dead. Tesla replaced. They had to reprogram car to accept fob.

 

[boaterva]

There are several threads about this, I had the same problem last year and also had to have Tesla reset the car’s fob programming. This seems to be one reason they do the fob battery replacement at the annual service because they have the car in the shop.

Last week I did replace the battery in one fob of my X and it worked. Here’s what I did different. I did it in a few seconds and within range of the car. I’m surmising that having the car awake and seeing the fob had it accept/re-acknowledge the fob when it came online. Before I did it in the house and it didn’t recognize it.

I’ve never heard of one dying killing both of them but anything is possible. I also thought that perhaps it has been made better with recent software but obviously not, so perhaps my process helped (short downtime, car active, etc.).

 

[Ryan MF]

Interesting...thanks for sharing. I still find it strange they would need to order new keys if it was a reset of the car's fob programming. you would think they could reprogram the existing ones. Hopefully there is no charge for the keys.

 

[Sandiegodoug]

There was no charge
Ranger had a hard time programming new fob. Was here at least an hour. The first replacement fob didn’t work either. Lucky he had a 2nd new one, was able to make work.

 

[Ryan MF]

There was no charge
Ranger had a hard time programming new fob. Was here at least an hour. The first replacement fob didn’t work either. Lucky he had a 2nd new one, was able to make work.

Good to know. Thanks

 

[Shaz]

This happened to us this week. One of our fob key battery was getting low, after replacing fob key refused to work. Took the same battery and installed it on to the working fob and that worked fine, so it definitely was not the battery. Contacted Tesla and was told a Ranger would come by to help. Got an email from the Tesla Ranger indicating that they are ordering parts (I'm assuming a new key fob) and the wait time for that is 1-2 weeks. Luckily we still have one working.

 

[soulreaver99]

i have the exact same issue with my Model S. At first I thought I bought a pack of dead batteries so I returned it. Got another one and it still did not work. Tried the old battery and it worked fine. This is the weirdest thing ever

 

[Freerster]

A week ago my car showed I had a low battery in my FOB and I thought it was wierd because service just changed them 3 months ago. I broght my other FOB out to see if it showed a low battery in that one and it did. Today I got new batteries and I changed them out. It still show low battery so i'm not sure what it is. Maybe it has something to do with the new update. Im calling service now and I will update when I find out and will l post later.

 

[Big Ike]

I’m having the same issue that my fob with the replaced battery is not being recognized by my MX. Looks like scheduling service is the only option to correct?
Thanks Gang!

 

[gangzoom]

Why does this happen? Does it mean every 2 years we all have to get new keys from Tesla?? What happens when the warranty is gone?

 

[boaterva]

Usually it’s fixable with a reset/reprogramming on the car’s side. Why it’s needed is another thing, makes no sense, but my experience doing it with the car powered up and ‘close’ to the car helped.

Interesting that before it was part of annual service and now that’s (annual service) no longer needed!

 

[DCGOO]

Usually it’s fixable with a reset/reprogramming on the car’s side. Why it’s needed is another thing, makes no sense, but my experience doing it with the car powered up and ‘close’ to the car helped.
Interesting that before it was part of annual service and now that’s (annual service) no longer needed!

The key fob is still a warranty item, even without annual service.

 

[mikerwalsh]

I got the low key fob warning, so I replaced the battery with a generic cheap battery, and it wouldn't work at all. I tried another one and same thing. I tested the cheap battery, 3.3v, so it should have worked, but when I put it in the key fob and tried opening doors, frunk, trunk several times, I took the battery out and it was down to 2.7 volts. Apparently it couldn't handle the current drain of operating the key fob. I went out and bought a Duracell 2032 battery, and now it works, but I can't get rid of the low battery warning on the dash! I can't figure out how to reset it.

 

[ShawnA]

Hi Mikerwalsh,

There is no procedure (known to me) for resetting the low battery warning...
I think when I saw it and put in new batteries it may have taken a day or two,
or a drive or two for the message to disappear.

Another trap could be having a low battery in your second fob...
Seeing you used a 2032 battery you must have a slightly older Model X.
The current battery for me is a CR2354.

Shawn

 

[mikerwalsh]

Hi Mikerwalsh,

There is no procedure (known to me) for resetting the low battery warning...
I think when I saw it and put in new batteries it may have taken a day or two,
or a drive or two for the message to disappear.

Another trap could be having a low battery in your second fob...
Seeing you used a 2032 battery you must have a slightly older Model X.
The current battery for me is a CR2354.

Shawn

Thanks, Shawn, I'll give it some time to reset. I have a 2014 Model S, sorry. I didn't notice this thread was in the Model X forum, I was just looking for key fob issues!

 

[boaterva]

Thanks, Shawn, I'll give it some time to reset. I have a 2014 Model S, sorry. I didn't notice this thread was in the Model X forum, I was just looking for key fob issues!

It's the same for both S and X. Mine both later had both warnings disappear a week later, go figure. Got the new batteries a couple of weeks later, replaced them, and all is well. It's still a mess. There should be a concrete way to have the car test the battery and reset it.

 

[mikerwalsh]

I got the low key fob warning, so I replaced the battery with a generic cheap battery, and it wouldn't work at all. I tried another one and same thing. I tested the cheap battery, 3.3v, so it should have worked, but when I put it in the key fob and tried opening doors, frunk, trunk several times, I took the battery out and it was down to 2.7 volts. Apparently it couldn't handle the current drain of operating the key fob. I went out and bought a Duracell 2032 battery, and now it works, but I can't get rid of the low battery warning on the dash! I can't figure out how to reset it.

Update: the warning just disappeared the next day all by itself, when it was good and ready. All is well.

 

[Joe B]

One of my MX key fobs stopped working this winter and the other key fob had a low battery warning so I went ahead and replaced both batteries. They were more than two years old.

After replacing the batteries neither fob worked. I ordered the same type of batteries and tried resetting them a few times. Today I took both keys to Tesla and they said they also could not get them to work and would order replacement keys.

This seems very strange that both fobs would completely stop working after a battery change? I suppose one could have died before but seems too coincidental. Has anyone experienced this or any ideas of how to bring them back to life?[/QUOTE
My model S key fobs all stopped working immediately after lates software upgrade on March 3 2020

 

[RFC7]

Chargeable warranty visit?

I have no idea how common this keyfob problem is, but for what it's worth, here is my input on the topic.
I picked up my X on March 11, 2020, in Bristol UK, (ordered Nov 9th) zero problems on the drive home to Mid Devon.
Sadly, due to the Coronavirus 'Big Red' has been on lockdown in the garage with under 100 miles on the clock, So no opportunity to try it out since arriving back. This is very frustrating as I live on a stretch of road that is used for Police 'Blue Light driver training', and is listed in the UK's top ten favorite driving roads, (ask any serious leather-clad biker !!).
In early April I must have picked up my wife's keyfob as when I went over to the garage I noticed the driver's door did not automatically open! I tried to back the car out and it was playing 'dead'. I suspected it must be the keyfob and fetched the second one, it worked perfectly, I switched the batteries over, still one dead keyfob.
The problem was reported to Tesla and I offered to mail the faulty keyfob back to them for exchange, but no, a home technician is now scheduled to visit my home on May 4th, which will be a 200 mile round trip from Tesla Bristol !! I do hope he/she arrives with a spare or at least a magic answer.....
Meanwhile, I had to agree to a possible £78.50 charge to my debit card, to cover the cost if the problem turns out to be a non-warranty situation, well the outcome of that will be very interesting !!!!
I hope the Technician is coming prepared and primed to stop the lowered windows of both front doors knocking when the doors are closed!
Watch this space.......
RFC7