Mazda CX-3 Key Fob Battery Remote Replacement DIY Years 2016-2019

I bet you will agree with me that the Mazda CX3 smart key fob comes with arrays of convenience. For starters, it allows you to lock, unlock, or panic your Mazda CX-3 remotely.

What’s really “smart” about it is that you can unlock or start your vehicle while the key is in your pocket. Your CX-3 will detect your smart key based on its proximity and grant you access.

There is more, this Mazda key fob also comes with a handy removable key for when your battery dies.

Speaking of your battery dying, let’s get into why you’re really here—to change the internal battery in your CX-3 key fob!

In this guide, you will discover everything you need to know to get your battery changed and get back out on the road in no time.

Looking for a different Mazda key fob?

CX-3Smart Key2016, 2017, 2018, 2019CR2025Check on Amazon

How to Replace the Mazda CX-3 2016, 2017, 2018, and 2019 Smart Key Fob Battery

Mazda cx3 key fob battery replacement

You can easily open this smart key fob to replace the old CR2025 battery inside with a new one. Scroll down to see a full video tutorial or read on for a step-by-step guide.

What you will need:
• 1x CR2025 battery
• Flat-head screwdriver

Final Image Mazda CX-3 Key

How to Change the Mazda CX-3 Smart Key Fob Battery

Total Time: 3 minutes

1. Switch to release valet key

Mazda CX-3 Key Switch to release valet key

First, flip your smart key over and find the small lever switch on the back. Push the switch down, and pull on the silver key ring hole to release the valet or internal key.

2. Loosen grooves with screwdriver

Mazda CX-3 Key Loosen grooves with screwdriver

Locate the grooves on the left and right walls from where the key came out. Insert your screwdriver into one of the grooves and twist to loosen that side. Repeat the same process for the groove on the other side. This will begin to separate the two halves of the key fob.

3. Separate two halves using screwdriver

Mazda CX-3 Key Separate two halves using screwdriver

Now, there should be a separation between the two halves running down the seams on the long sides of the smart key. Insert your screwdriver into these seams, twist, and work your way down each side until you can separate the two halves of the key fob.

4. Remove plastic holding battery

Mazda CX-3 Key Remove plastic holding battery

Remove the piece of plastic holding the battery with your finger to expose the old battery so you can easily remove it with your fingers, also.

5. Insert new CR2025 battery, reassemble fob, done.

Mazda CX-3 Key Insert new CR2025 battery, reassemble fob, done

Fix your new battery replacement in the compartment with the positive side face-UP. Return the plastic disc on top of the battery, click the two halves of the key fob back together, and insert your internal key.

That’s it! You’ve successfully carried out a Mazda cx3 key fob battery replacement. Good job!

Mazda CX-3 Smart Key Fob Battery Replacement (2016 - 2019)

This is the battery for this CX-3 key fob:

Cautions To Take When Installing Your Mazda CX3 Battery

  1. Ensure the battery is correctly installed otherwise, your key fob may experience battery leakage.

  2. Be careful not to touch or tamper with the electrical terminals and internal circuits when replacing your battery. Also, do not get dirt in the transmitter to avoid damaging it.

  3. Note that improper or incorrect replacement could lead to battery explosion which may cause serious injury.

  4. Dispose of your used batteries according to these instructions.

    • Do not disassemble.

    • Do not throw the old battery into the water or fire.

    • Do not crush or deform the battery.

  5. Ensure you only replace the old battery with the same battery type (CR2025 or equivalent).

Signs Your Mazda CX3 Key Fob Battery Power Is Low

  • The key indicator light, green, will flash in the instrument cluster for like 30 seconds after your engine is switched off.

  • When you press the buttons on the key fob, the operation indicator light does not flash.

  • The operational range at which the device functions is reduced. That is, the doors will not lock or unlock until you move really close to your car.

Frequently Asked Questions

What battery does a Mazda cx3 key use?

CR2025 battery is often the only and most suitable battery for a Mazda CX3 key fob.

How do I change the battery in my Mazda CX 3 key?

It’s simple and straightforward steps as shown above. Scroll up for detailed instructions on Mazda CX3 key fob battery replacement or watch the quick tutorial videos.


Replacing your Mazda cx3 key battery shouldn’t take you to the dealership or cost you extra money when you have the above DIY remote key fob battery replacement guide. Follow the instructions above when next your key fob battery dies on the road trip.

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