Tire Monitoring System: Description and Operation

Tire Pressure Monitor Description and Operation
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 remote control door lock receiver (RCDLR), 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. If the vehicle is equipped with the Japan export (UH3) option, the system also uses 4 tire pressure receivers and a tire pressure module. 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 RCDLR 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 RCDLR. The RCDLR translates the information within the sensors radio frequency transmission into sensor presence, sensor mode, and tire pressure. The RCDLR then sends this information to the DIC via the serial data circuit where the tire pressures and there locations are displayed. The DIC displays the pressure of each tire.

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 Label - Vehicle Certification, Tire Place Card, Anti-Theft and Service Parts ID, or to Label - Vehicle Certification, Tire Place Card, Anti-Theft and Service Parts ID. The sensors pressure accuracy from -10 to +70°C (+14 to +158°F) is plus or minus 7 kPa (1 psi). The RCDLR 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 RCDLR, refer to Keyless Entry System Description and Operation.