Key battery warning
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Joined: Jul 2022
Posts: 464
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2014 E63 / 2017 CLS 63 / 2015 G63
Key battery warning
Replaced with new duracell 2025. Still the same message….
again swapped out the newly placed battery thinking perhaps it’s the bad batch. With second new battery placed in, the same message.
what’s going on here?
again swapped out the newly placed battery thinking perhaps it’s the bad batch. With second new battery placed in, the same message.
what’s going on here?
Out Of Control!!
Joined: Apr 2019
Posts: 12,002
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From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
Fob Fault Reset
The firmware requires a MANUAL RESET to clear low fob warning.
There is a weird service procedure to clear that. See youtube vídeo... I don't quite remember (key cycles On/Off/On) - I use CR2032 that last many years like most Jp cars.
Last edited by CaliBenzDriver; Apr 10, 2026 at 11:47 PM.
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MBWorld Fanatic!
Joined: Jan 2012
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From: NYC
E63S
Interesting.
I never owned a car that chewed through as many key fob batteries as the W212 E63. I had success in getting rid of the message by simply swapping a new battery in the fob multiple times in the 7+ yrs I owned mine.
I never owned a car that chewed through as many key fob batteries as the W212 E63. I had success in getting rid of the message by simply swapping a new battery in the fob multiple times in the 7+ yrs I owned mine.
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Joined: May 2025
Posts: 4
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2014 E63s
I'm glad I found this thread, I thought my keyfob was defective.
I've tried various different brands, discounter, Duracell, Varta, etc... I feel like I keep changing the battery every 1-2 months.
Next time I'll try to put a CR2032, thanks @CaliBenzDriver for the tip. Didn't know it fits.
I've tried various different brands, discounter, Duracell, Varta, etc... I feel like I keep changing the battery every 1-2 months.
Next time I'll try to put a CR2032, thanks @CaliBenzDriver for the tip. Didn't know it fits.
Out Of Control!!
Joined: Apr 2019
Posts: 12,002
Likes: 6,827
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
Plan-B is best!
I'm glad I found this thread, I thought my keyfob was defective.
I've tried various different brands, discounter, Duracell, Varta, etc... I feel like I keep changing the battery every 1-2 months.
Next time I'll try to put a CR2032, thanks @CaliBenzDriver for the tip.
Didn't know it fits.
I've tried various different brands, discounter, Duracell, Varta, etc... I feel like I keep changing the battery every 1-2 months.
Next time I'll try to put a CR2032, thanks @CaliBenzDriver for the tip.
Didn't know it fits.
