When you add air to your tires, make sure you replace tire valve caps immediately. If your 2018 Mazda MX-5 rf has a Tire Pressure Monitoring System the tire valve cap might be integral to the proper operation of your tire pressure monitoring system. If you remove the cap and replace it with the wrong tire valve cap, you could get a false tire pressure system low pressure light.
The tire valve caps for tpms systems serve as the
broadcast antenna for the transmitter. If you replace valve stem caps with a plastic cap or an aftermarket metal cap, you may get false “low tire pressure” warnings on your dash gauges. If a metal cap is missing, always replace it with a cap from the dealer.