These instructions apply to the Mazda 3 Mk2 (BL) 2009-2016. For other models, please choose your vehicle here.
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If the remote on your Mazda 3 Mk2 (BL, 2009–2016) has become weak — you have to stand close to lock or unlock — the fob’s coin cell needs replacing. The Mazda 3 remote uses a CR1620 cell. This generation also lets you re-register a remote yourself without a dealer tool. This guide covers both.
What You Need
- One fresh CR1620 3 V lithium coin cell.
- A small flat-blade screwdriver.
How to Replace the Battery
- Unclip the remote control unit from the main key — use a screwdriver at the marked arrow.
- Remove the key cover with the screwdriver.
- Lift out the old CR1620 cell.
- Fit the new cell with the positive (+) side facing down.
- Refit the cover and engage the remote unit back onto the main key.
- Check the remote locks and unlocks the car.
Re-registering a Remote Yourself
If the remote has lost its pairing (or you’re adding a spare — up to 3), the Mazda 3 can be put into programming mode without a tool:
- Remove the key, close all doors and the boot, then open the driver’s door.
- Within 24 seconds, insert the key and turn the ignition ON and OFF 3 times (leave the key in).
- Close and open the driver’s door 3 times — the door locks cycle to confirm programming mode.
- Press any button on the remote twice — the locks cycle to confirm it’s registered.
- Repeat for any other remotes, then close the door to exit.
Note: a brand-new transponder key (for starting) still needs a dealer to code the immobiliser.
Frequently Asked Questions
What battery does the Mazda 3 BL remote take?
A CR1620 3 V lithium coin cell, fitted positive-side-down.
Can I really program a remote without a dealer?
Yes — the ignition-cycle and door sequence above registers the remote’s button functions. It doesn’t program a new transponder for starting (that needs a dealer).
My remote still won’t work with a fresh cell — now what?
Re-open it and check the cell orientation and that the contacts are clean. If it’s still dead, try re-registering with the sequence above; if that fails, the fob may have an internal fault.
For battery work that may also be needed, see our Mazda 3 battery disconnect/reconnect guide. For warning lights, look up the code on autodtcs.com.
Disclaimer: The information on this page is provided for general guidance only. Always follow your official service manual and safety precautions when working on your vehicle. We are not responsible for errors, omissions, or any damage resulting from the use of this information.
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