Learn How to Open Your Mazda Key to Replace a Dead Battery

By Product Expert | Posted in Tips and Tricks on Tuesday, January 5th, 2016 at 8:37 pm
How to Replace Mazda Key Fob Battery

Having your Mazda key battery replaced by a qualified service technician is best to avoid damaging your key.

How to Replace Mazda Key Fob Battery

Like any battery, the battery in your Mazda’s key fob could go dead, requiring a replacement. But how do you open up the Mazda key fob? Although it is recommended you work with certified technicians at an authorized Mazda dealer to avoid damaging your key fob, it is your car after all, and sometimes you’ll want to handle your own maintenance. That’s why we’re here to show you how to replace the Mazda key fob battery (current for the 2016 model year).

What You Will Need:

  1. Your key fob.
  2. A tape-wrapped flathead screwdriver.
  3. A replacement battery.

If you’re unsure if your battery is really dead or at low power, there are a few ways to tell. If the KEY dashboard warning light illuminates in the instrument cluster after the engine is off, if the key fob or its operation indicator light do not work or if the key fob’s operational distance is less than normal, your key’s battery is likely headed the other way. Now, if you have all the needed materials, let’s get started.

Changing Mazda Key Battery

changing mazda key batteryBe sure to use your owner’s manual as the best reference and for the most up-to-date procedures for replacing the key battery. These steps are updated for the 2016 model year. Keep in mind that other model years may differ.

  1. Remove the auxiliary key by pressing the knob on the back of the key fob. [What is the auxiliary key?]
  2. Take your tape-wrapped flathead screwdriver and insert it into the opening. Twist it toward the end opposite of the opening to loosen the key fob cover slightly. Once the cover is loosened, insert the screwdriver into the gap you’ve created on the outside of the key fob and slide it down to the other end of the key fob to further loosen the cover until you can remove it.
  3. Once the cover is removed, you can remove the round battery cap. Then, remove the battery. If the rubber ring detaches during this step, be sure it does not get scratched or damaged.
  4. If necessary, reattach the rubber ring before inserting a new battery.
  5. Then, take your new battery, with the positive side facing the top of the key fob, and insert it into the key.
  6. Replace the battery cap.
  7. Replace the key fob cover, which should snap into place.
  8. Lastly, reinsert the auxiliary key.

[Read more: What to do if you lose your car keys]

Again, though you can try figuring out how to replace the Mazda key fob battery yourself, we always recommend working with a qualified Mazda technician to avoid damaging the key. Either way, be sure to consult your owner’s manual before attempting to disassemble the key fob in anyway, or schedule an appointment with our service team online.

15 Responses to “Learn How to Open Your Mazda Key to Replace a Dead Battery”

  1. Gabrielle says:

    Why aren’t there pictures to go with this? My dealer explained how to do this and it isn’t worked, nor are your instructions. Video and/or pics would help. We don’t all live close to a dealer….

  2. Roger C says:

    Well written and easy to follow peice except for one thing, you didnt state what size of battery i.e CR1620 or other, it would mean opening the key fob, find batery size, then reassemble the key fob, going to get a battery and then returning then finally carrying out the replacement.
    Thanks for the information and i now have a working keyfob again. cheers

  3. Jeremy says:

    These instructions are great but I was having a hard time opening the key shell of my Mazda 3. For those wondering about the battery size or want to watch a video on how to do this check this out. https://www.youcanic.com/vehicles/mazda/mazda-key-battery-replacement

  4. Kevin says:

    Easy instructions to follow. It is a CR2025 battery you need

  5. Nick Brooke says:

    Missing step 4½: Remove the plastic cover from the negative side of your new battery before inserting it into the key fob, you dummy.

  6. Perfect instructions – you need to go “gingerly” when twisting with the thin flat headed screwdriver to avoid damaging the cover. I noticed that any 3V battery of the same size works.

  7. Micah says:

    I have had no issue changing the battery, but my issue is that as soon as i put the plastic cover back on the car alarm starts going off. I’m not sure what is causing the issue. Ideas?

  8. Pete says:

    Last time I tried to change the the battery I broke to cover. Fortunately I found replacement part on ebay. Now, my wife’s mazda needs to have the fob battery replaced so I decided to do some research before I start. Great info thanks.

  9. Jason says:

    We have the same issue with our cx9 fob. Have you resolved?

  10. David says:

    RE: stevenp and Nick Brooke: The Duracell battery I bought had a sticker over the negative end of the battery taht had to be removed before isntalling.
    stevenp – I think the comment was a self deprecating remark, chill out some.

  11. JimS says:

    I believe Nick was calling himself a dummy. The reason I know this is because I too am a dummy and didn’t see the plastic on the negative side and couldn’t figure out why it didn’t work. Opened it up again and sure enough.

  12. Sean Bulanda says:

    This video was perfect. Thanks!

  13. Sean Bulanda says:

    I meant the video suggested by wayned. Yes there is no video on this page. :b

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