Have you figured out the issue yet? I had the same problem with my CX5 due to loose wire from the ignition switch. Dealer investigated this issue and fixed it. Hope it helps.
Have you solve this issue yet? If not, it maybe TPMS sensor issue due to a weak or failing over even died battery. It should also be tires that serviced or rotated and the relearn procedure was not done correctly. Take a closer look at them.
You try to disconnect and reconnect the battery to see if this code disappear or not? Also cleaning wheel sensor is a good start. You can use a TPMS diagnostic scanner that is able to troubleshoot Mazda TPMS system and retrieve the error codes that what i read. Hope you can solve this problem.
It could be battery issue. But it is also a lack of fuel and/or spark that make engine light on. Using OBD2 scanner to diagnose what the issue is before replacing battery.
TPMS does not come with spare time. Here are some links that you can refer to figure out the issue and solution. Hope it help.
https://www.mazdausa.com/static/manuals/2018/cx5/contents/05120200.html
https://www.youcanic.com/wiki/reset-mazda-tire-pressure-sensor-tpms-light
You buy automotive diagnostic system known as OBD-II on Amazon, ebay that to monitors a number of engine and emissions-related components. This item can show you the issue is and you can fix the issue and then wait for the system to reset itself when it determines the problem is fixed.
Amazon is my vote. There are a lot of amplifiers modeling that you can compare the function also the price. It has both new and used products. Hope you can choose the best one.