The TPMS warning light came on on my wife's 2018 Elantra. One tire was slightly below the trigger level and I easily pumped it back up. However the warning light still refuses to go out even after driving for various times at various speeds (up to and including 1/2 hour at 75 mph)
The users manual states (in the "Changing a tire with TPMS" section)
Once the original tire equipped with a tire pressure monitoring sensor is reinflated to the recommended pressure and reinstalled on the vehicle, the Low Tire Pressure LCD position indicator and TPMS Malfunction Indicator will go off within a few minutes of driving
I googled for solutions to this and could't find a suitable answer. Some Hyundai's apparently have a reset button under the steering wheel, but as far as I can tell this model doesn't. Another video I saw (not in English), seemed to suggest connecting an OBD2 reader and using that to reset the light. This is confusing me, as on my Subaru the light resets automatically when you start the car and drive for a bit if the pressures are above minimum.
So what is the solution to this?
Note that there is also a TPMS Malfunction Indicator that uses the same warning light on the dash. The manual says that this is indicated by flashing the warning light for 1 minute before going solid after starting the car. This light comes on solid and doesn't flash, so IMHO it is not indicating a system fault.