The Tire Pressure Monitor (TPM) system notifies the driver when a significant loss of tire pressure occurs in any of the 4 tires.
The system uses the powertrain control module (PCM), body control module (BCM), instrument panel cluster (IPC), DIC, a radio frequency (RF) transmitting pressure sensor in each wheel/tire assembly, and the serial data circuit to perform the system functions.
When the vehicle is stationary the sensor's internal roll switches are open, which puts the sensors into stationary mode. In this mode the sensors transmit once every 60 minutes to minimize sensor battery consumption. As vehicle speed increases, centrifugal force closes the sensor's internal roll switches causing the sensors to go into drive mode. In this mode the sensors transmit once every 60 seconds. The BCM receives and translates the data contained in each sensor's RF transmission into sensor presence, sensor mode, and tire pressure.
When the TPM system detects a significant loss of tire pressure, the CHECK TIRE PRESSURE message is displayed on the DIC and the low tire pressure indicator is displayed on the IPC. Both the message and indicator can be cleared by adjusting the tire pressures to the recommended kPa/psi. The sensors pressure accuracy from -10 to +70°C is ±7 kPa. The BCM has the ability to detect malfunctions within the TPM system. Any malfunction detected will cause the DIC to display the SERVICE TIRE MONITOR message.