A tire pressure monitoring system includes an on-board detection unit configured
to transmit a detection signal indicative of the presence of an occupant entering
a vehicle, a vehicle-body-based unit configured to receive the detection signal
and transmit a transmission request to receive at least one air pressure signal
indicative of tire pressure of the vehicle, and at least one tire-based unit configured
to receive the transmission request, measure the tire pressure and transmit the
air pressure signal.