After a few years of daily use, the battery inside the “smart” or “intelligent” key fob remote control for the Advanced Keyless Entry system of a 4th generation (2016, 2017, 2018, 2019, 2020 & 2021) Mazda MX-5 Miata can become weak or stop working entirely. Check out my DIY instructions for changing the battery (with the compatible replacement part number) by clicking on the text link or thumbnail image below.
2016-2021 Mazda MX-5 Miata Key Fob Battery Replacement Guide
