The tire pressure monitor (TPM) system warns the driver when a significant loss of tire pressure occurs in any of the 4 tires, and (w UK3) allows the driver to display the individual tire pressures, and their locations on the driver information center (DIC).
The system uses the powertrain control module (PCM), body control module (BCM), instrument panel cluster (IPC), DIC, liftgate module (LGM), a radio frequency (RF) transmitting pressure sensor in each wheel/tire assembly, and the serial data circuit to preform the system functions.
When the vehicle is stationary and the sensor's internal roll switches are open for at least 30 seconds, the sensors go into stationary mode. In this mode the sensors sample tire pressure once every 20 seconds and transmit a stationary mode transmission once every 60 minutes. As vehicle speed increases, centrifugal force closes the sensor's internal roll switch causing the sensors to go into drive mode. In this mode the sensors sample tire pressure once every 30 second and transmit a drive mode transmission once every 60 seconds. The LGM receives and translates the data contained in each sensor's RF transmission into sensor presence, sensor mode, and tire pressure. The LGM then sends the tire pressure and tire location data to the DIC via the serial data circuit where they are displayed as follows:
| • | LF TIRE XX PSI |
| • | RF TIRE XX PSI |
| • | RR TIRE XX PSI |
| • | LR TIRE XX PSI |
The sensors continuously compare their current pressure sample with their last pressure sample and will transmit in re-measure mode whenever a 1.6 psi change in tire pressure has occurred. 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 DIC message and IPC indicator can be cleared by adjusting the tire pressure to the recommended kPa/psi. Refer to Vehicle Certification, Tire Placard, Anti-Theft, and Service Parts ID Label . The sensor's pressure range is 0-703 kPa (0-102 psi). The sensors pressure accuracy from -10 to +70°C (+14 to +158°F) is plus or minus 14 kPa (2 psi).
The LGM has the ability to detect malfunctions within the TPM system. Any malfunction detected will cause the DIC to display the SERVICE TIRE MONITOR message. For more information on other functions of the LGM, refer to the following:
