Tire Pressure Monitor Description and Operation

WARNING: This page is about a different car, the 2004 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.

The Tire Pressure Monitor (TPM) System warns the driver when a significant increase, or decrease 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 powertrain control module (PCM), 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 roll switches are open, which puts the sensors into stationary mode. In this mode the sensors transmit once every 60 minutes. As vehicle speed increases, centrifugal force closes the sensors internal roll switches, which puts the sensors to go into drive mode. In this mode the sensors transmit 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:

FRONT L XX R XX PSI
REAR L XX R XX PSI

When the TPM system detects a significant decrease of tire pressure, the LOW TIRE PRESS XX, or XX TIRE FLAT - MAXIMUM SPEED 55 MPH - REDUCED HANDLING messages are displayed on the DIC and the low tire pressure indicator is displayed on the IPC. When the system detects a significant increase of tire pressure the HIGH TIRE PRESS XX message is displayed on the DIC. Both the messages and indicator can be cleared by adjusting the tire pressures to the recommended kpa/psi. Refer to Tire Placard in General Information, or to Tire Inflation Pressure Specifications (1) in Maintenance and lubrication. The sensors pressure accuracy from -10 to +70 degrees C is +/- 7 kPa (1 psi). The system also compensates for changes in barometric pressure using the PCMs map sensor via the serial data circuit.

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 in Keyless Entry.