Categories: Service

Mercedes-Benz Key Fob Not Working? How to Replace the Battery

How to Change a Mercedes-Benz Key Fob Battery

You’re heading out, iced coffee in one hand, key fob in the other—Click. Nothing. Your Mercedes-Benz key fob isn’t unlocking the doors, and you’re standing in the Peoria, AZ, heat like, “Seriously?!” Don’t panic—Mercedes-Benz of Arrowhead is here to help. If you’ve been wondering how to change a Mercedes-Benz key fob battery, we’ve got a quick guide that’ll get you back on the road in no time.

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Step-by-Step Guide to Change a Mercedes-Benz Key Fob Battery

“Alright, what’s step one?” That’s what my neighbor Mike asked as we tackled his key fob on a sunny Saturday morning.

Here’s what we did: First, you’ll need a CR 2032 3V coin cell battery—easy to find at most grocery stores or hardware shops.

Then, pop out the emergency key. Slide it from the bottom of the fob. Easy.

Insert that same key into the small slot—you’ll see it. Push gently in the direction of the arrow until the cover pops up. Don’t try to hold the cover shut at the same time—it needs to lift.

Use the emergency key to pry the cover off carefully. Once you’re in the right spot, it should lift easily.

Tap the fob gently against your palm. The old battery should fall out. If not, a gentle shake usually does the trick.

Take your new battery and place it in—positive side up. Use a clean, lint-free cloth to avoid getting oils or dirt on it.

Snap the cover back into place. Make sure the front tabs slide into the housing first, then press down evenly on both sides.

Re-insert the emergency key. That’s it.

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Mike gave me a high five and said, “Honestly, that was way easier than I thought.” So, if your key fob is acting up in Peoria, now you know precisely how to change a Mercedes-Benz key fob battery. Still feel unsure? No stress—swing by Mercedes-Benz of Arrowhead and let our pros handle it for you. Either way, no more standing outside your Benz, locked out and frustrated.