Replace the key fob cover which should snap into place.
Mazda 3 key fob battery replacement 2016.
Replacing the battery cr 2025 in the mazda advanced keyless system key fob i am not a big fan of speaking so fewer words more work.
Lastly reinsert the auxiliary key.
All you need is a small flat head or pocket screwdriver a replacement battery from your local.
This is the battery for this mazda 3 key fob.
Replace the battery cap.
Amazonbasics cr1620 lithium coin cell battery 2 pack.
2 pack of cr1620 lithium coin cell batteries for small electronic devices.