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Key Fob Battery Low Warning - please help

Polly Wog

Dec 4, 2013
Kihei, Hawaii
I’ve been a Model S owner for nearly 7 years, and I’m stumped on the problem I’m having now. In my 2019 Model S, both key fobs started generating the “key fob low battery” warning on the same day. I did a MCU reboot with no change. I then replaced the battery in one fob, with no effect - the warning remains. Fast forward 2 months. 3 days ago, while driving my original 2014 Model S that we keep on the mainland, the “key fob low battery” warning appeared. Because I figured it had been a year since it had been replaced, I put a brand new battery in the key fob. No luck, the warning remains. My wife then told me that she started getting the same warning with her key fob on the same day! Once again, I did a MCU reboot with no change. I also did an IC reset, with no change.

Does anybody here in Tesla land know what to do about this? A service appointment seems ridiculous, but I don’t know what to do. It is super annoying! Thanks!


A'-Lo-HA ! y'all
Nov 26, 2012
Kaneohe, HI
@Polly Wog, The fobs don't behave these last few years as they did in the early years. What does that mean ??
Its customary these days that after you replace the battery in one, you need to take both fobs (even the one that you did not change) to the car. Sit in the car with both and reboot the center console. Usually, (not always), but usually this has cleared the message. If it does not give it a little time, like roll down a window, and leave both in the car for a short time and come back and try again.

Why this is happening only Tesla knows. When exactly did this start? Not sure, but its been going on a while. I think you might ask then, why doesn't it need both when the SC replaces just one battery because they have only the one fob. I don't know their secret. I asked once, and never got an answer between asking the SA and getting the tech to answer.

However give the two present fobs in the car trick a try.


My grandfather’s car
Dec 3, 2018
New England, USA
There are a lot of fake (counterfeit) batteries coming from China. I’ve ended up with some from Amazon, branded Samsung. They work for a short time then have low voltage. Very frustrating.

Try using other batteries from another source.

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