A system and method for monitoring vehicle tire pressure. A tire pressure monitor for each tire includes a pressure sensor for sensing tire pressure, a transmitter for transmitting a tire pressure signal representative of the sensed tire pressure, and a batter providing power to the transmitter. To conserve battery power, each tire pressure signal transmitted by the transmitters includes a wake-up signal only when the vehicle has been stationary for a predetermined time period. The wake-up signal ensures receipt of the tire pressure signal by a vehicle mounted receiver alternating between active state and inactive states.