The Tire Pressure Monitor (TPM) System warns the driver when a significant loss of tire pressure occurs in any of the 4 tires and allows the driver to display the individual tire pressures on the driver information center (DIC) while the vehicle is being driven. The system uses the AM/FM antenna grid in the driver side rear glass, antenna module, dash integration module (DIM), DIC, instrument panel cluster (IPC), 4 radio frequency transmitting pressure sensors inside each wheel/tire assembly, and the serial data circuit to perform the system functions. When vehicle speed is less than 32 km/h (20 mph), the sensors go into stationary mode. In this mode the sensors transmit to the antenna module through the AM/FM antenna grid once every 60 minutes to minimize sensor battery consumption. As vehicle speed increases to 32 km/h (20 mph), centrifugal force closes the sensor's internal roll switch causing the sensors to go into drive mode. In this mode the sensor transmits once every 60 seconds to the antenna module. The antenna module translates the information within the sensors radio frequency transmission into sensor presence, sensor mode, and tire pressure. The antenna module then sends this information to the DIC via the serial data circuit where the tire pressures and there locations are displayed. The DIC displays a graphic overhead view of the vehicle, and displays the pressure of each tire at each respective corner of the graphic.
If the TPM system detects a significant loss of tire pressure, or if a tire is over inflated, the tire pressure of the low tire displayed on the DIC will flash, and the low tire pressure warning indicator is displayed on the IPC. The IPC indicator can be cleared by adjusting tire pressures to the recommended kPa/psi. Refer to Tire Inflation Pressure Specifications in Maintenance and Lubrication, or to Vehicle Certification, Tire Placard, Anti-Theft, and Service Parts ID Label in General Information. The sensor's pressure accuracy from -10 to +70°C (+14 to +158°F) is plus or minus 7 kPa (1 psi). The antenna module has the ability to detect malfunctions within the TPM system. Any malfunctions detected will cause the DIC to display the SERVICE TIRE MONITOR warning message. For more information on other functions of the antenna module, refer to Radio/Audio System Description and Operation in Entertainment, and to Keyless Entry System Description and Operation in Keyless Entry.