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Key battery needs replacing? It's new!


May 30, 2017
I had that message on my screen for a month. I had taken it into the service center a week after this message started happening. Brought both fobs with me. They replaced the fob batteries and said the message should go away soon. It didn't. I replaced both batteries on my own twice and still had the message. A mobile service tech came to take care of a different issue on the car and I explained the situation to him about the fobs and he replaced both of them on the spot for me under warranty. He said if I had gone through that whole process that many times then most likely one of the fobs was malfunctioning and it would be best to replace.

Bill D

Oct 11, 2013
Weston, FL
Previously when I replaced the battery in my key, the message went off, but today, I had to replace the battery in both my keys to get rid of the message. The difference this time was that my wife used my 2nd key while the message was ON. Therefore I believe it works like this:

The message goes ON when the car sees a key with a low battery and goes OFF when it sees that SAME KEY with a new battery.

However, if the message is ON and the car sees the 2nd key with a low battery, the message goes DOUBLE-ON so it needs to see both keys with new batteries before it goes OFF.

Both my batteries measured 2.99 volts, so it seems like a battery is low if it is under 3 volts (new batteries are 3.3 volts).

BTW - a pack of 20 Sony batteries are only $7.50 on Amazon.
  • Informative
Reactions: bayx and P85_DA


Twice as much fun
Oct 14, 2015
Central MA
I just bought 2 of the CR2354s at BatteriesPlus. There were too many bad reviews of various CR2354s on Amazon that I felt like I didn't want to trust any of them. I'd have preferred cheaper batteries, but $11/year for 2 new fob batteries isn't something I'll worry about.

(BatteriesPlus has 10% off if you buy online and pickup in store, which is what I did)

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