How to Change the Battery in a Mercedes-Benz Key Fob

Mercedes-Benz Key Fob on Table

If you’re experiencing difficulties with your Mercedes-Benz key fob, it could be due to a dying battery. The steps for how to change the battery in a Mercedes-Benz key fob at home in Springfield are simple and easy to follow, but they will vary depending on your vehicle’s model year. In the guide below, the service team at Mercedes-Benz of Eugene provides the battery replacement steps for both older and newer key fob styles. 

Warning Signs of a Dying Mercedes-Benz Key Fob Battery

How will you know if it’s time to swap out your old Mercedes-Benz key fob battery for a new one? Some common warning signs you may experience include:

  • It may become increasingly difficult to start your Mercedes-Benz, requiring several attempts before a successful start. 
  • Your key fob’s lock, unlock, and panic buttons are no longer functioning.
  • The “Replace Key Battery” warning light pops up on your dashboard. 

Steps to Replace the Key Fob Battery for Newer Models

If your Mercedes-Benz vehicle is from the model year 2017 or later, you likely have the newest type of Mercedes-Benz key fob. These key fobs use a CR2032 battery. Here are the steps to replace the battery in this type of key fob:

  1. Press the small button located at the bottom of the rear side of your key fob.
  2. While pressing the button, slide the black cover piece off the key fob.
  3. On the side of the key fob is a small tray that holds the battery –– gently pull it out using your fingernail.
  4. Remove the old battery from the tray. Replace it with a new CR2032 battery with the plus side facing down.
  5. Re-insert the battery tray and put the black cover piece back on, ensuring the two small tabs slide securely into place.

Steps to Replace the Key Fob Battery for Older Models

Mercedes-Benz vehicles from the model year 2016 and prior use an older type of key fob, identifiable by its chrome and matte black plastic casing. There is also a distinctive panic button which exists on a dedicated tab at the bottom of the fob. These key fobs use a CR2025 battery. Here’s how to change the battery in an older Mercedes-Benz key:

  1. Turn the key fob on its end, revealing a small black release switch on the bottom. 
  2. Push down on the release and pull the key blade out.
  3. Place the head of the key blade into the slot you removed it from, gently nudging it until it triggers the tab that holds the black key fob cover piece in place. Remove the cover.
  4. Gently tap the key fob on your hand to loosen the old battery out of place. Replace it with your new CR2025 battery with the plus side facing up. 
  5. Push the cover piece securely into place, then put the key blade back into its slot.

Do you have a key fob that has no chrome, but is instead full black plastic? These fobs are rarer these days and are a bit older than those described above. You will follow the same steps, but instead of removing a cover piece after triggering the tab in step 3, you’ll be pulling out a tray that holds the CR2025 batteries. Note that these key fobs require two batteries. Once you’ve replaced them, slide the battery tray and the key blade back into place.

Need a New Key? Contact Us for Mercedes-Benz Service Costs

If you need help replacing the battery in your Mercedes-Benz key or you need a full key fob replacement, Mercedes-Benz of Eugene is conveniently located near Roseburg and Corvallis. Please contact us or schedule an appointment to get started today. Our parts center can provide Mercedes-Benz service cost info for key fob issues and answer any additional questions you may have. We’re here to make your Mercedes-Benz ownership experience simple and stress-free!

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