If all four wheel sensors in the subject vehicles are simultaneously malfunctioning or missing, the TPMS will provide an initial warning, but this warning will not automatically repeat on subsequent ignition cycles, failing to remind the driver that the system is offline.

" The tire pressure monitoring system indicators may only illuminate for a portion of the time required by the standard and under certain conditions may not re-illuminate immediately after the vehicle is restarted as required.

What to do: Book it in at your next service. There is no deadline and no charge.