Tire Pressure Monitor Description and Operation UJ6

The tire pressure monitor (TPM) system warns the driver when a significant loss, or gain of tire pressure occurs in any of the 4 tires and allows the driver to display the individual tire pressures and their locations on the driver information center (DIC).

The system uses the engine control module (ECM), body control module (BCM), instrument panel cluster (IPC), DIC, remote control door lock receiver (RCDLR), 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 sensors internal accelerometer is inactive, which puts the sensors into a stationary state. In this state the sensors sample tire pressure once every 30 seconds and do not transmit at all if the tire pressure does not change. As vehicle speed increases, centrifugal force activates the sensors internal accelerometer causing the sensors to go into rolling mode. In this mode the sensors sample tire pressure once every 30 second and transmit in rolling mode once every 60 seconds. The RCDLR receives and translates the data contained in each sensors RF transmission into sensor presence, sensor mode, and tire pressure. The RCDLR sends the tire pressure and tire location data to the DIC via the serial data circuit where they are displayed as follows:

The sensors continuously compare their last pressure sample to their current pressure sample and will transmit in re-measure mode if a 1.2 psi change in tire pressure has been detected in either a stationary, or rolling state. When the TPM system detects a significant loss, or gain 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 range is 0-116 psi. The sensors pressure accuracy from -10 to +70°C is +/- 13.7 kPa (2 psi).

The RCDLR 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 RCDLR, refer to Keyless Entry System Description and Operation .

Tire Pressure Monitor Description and Operation UH3

The tire pressure monitoring system alerts the driver when there is a large change in the air pressure of one tire. The system learns the air pressure at each tire throughout the operating speed range of the vehicle, and compares tire rotational speeds using the antilock brake system's wheel speed sensors. The tire pressure monitoring system will not alert the driver before driving the vehicle that a tire is low or flat. The driver must begin driving the vehicle before the system will work properly.

The CHECK TIRE PRESSURE warning message, on the driver information center (DIC), and the tire pressure warning light, on the instrument panel cluster, will illuminate f the system detects a pressure difference in one of the four tires installed on the vehicle. For additional information and details about the DIC operation and displays refer to Indicator/Warning Message Description and Operation and Driver Information Center (DIC) Description and Operation .

The tire pressure monitoring system may not warn the driver of a tire pressure condition if :

If the tire pressure warning light illuminates and the CHECK TIRE PRESSURE message is displayed on the DIC, measure the air pressure in all four tires and adjust or repair if necessary. Refer to Tire Inflation Description and Vehicle Certification, Tire Placard, Anti-Theft, and Service Parts ID Label .

The tire pressure monitoring system does not set any diagnostic trouble codes (DTCs).

If tire pressure is adjusted or one or more tires is repaired, replaced, or rotated, the tire pressure monitoring system must be reset.

To reset the tire pressure monitoring system:

1. Turn the ignition switch to RUN, with the engine off.
2. Press the vehicle information button on the DIC until the PRESS Set/Reset TO RESET TIRE SYSTEM message appears on the display.
3. Press and hold the DIC Set/Reset button for five seconds. After five seconds, the display will show TIRE PRESSURE SYSTEM RESET.

The system completes the calibration process during driving. The system learns the pressure at each tire throughout the operating speed range of your vehicle. The system normally takes between 20 and 45 minutes of driving in each of the following speed ranges to learn tire pressures: 40 to 64 km/h (25 to 40 mph), 64 to 96 km/h (40 to 60 mph), and 96 to 136 km/h (60 to 85 mph). This time may be longer depending on individual driving habits. Learning need not be accumulated during a single trip. Once learned, the system will remember the tire pressures until the system is reset.