TPMS Function

The TPMS uses 4 valve stem mounted sensors to monitor tire pressure. These sensors wirelessly transmit tire pressure data to the BCM. The BCM contains a radio signal receiver which collects the tire pressure data.

All TPMS functions are controlled by the BCM. The BCM compares the tire pressure data sent by the sensors with a programmed tire pressure. This programmed pressure is specified on the VC label and cannot be changed. If the actual tire pressure is less than the programmed tire pressure, the BCM sends a low tire pressure message to the IPC along the MS-CAN. The IPC responds by illuminating the TPMS warning indicator and displaying a low tire pressure message in the message center. The TPMS sensors are trained (calibrated) to the BCM which records the unique identifier for each TPMS sensor and records the location of each sensor based on the training (calibration) order.

The diagnostic scan tool is a useful tool in diagnosing TPMS concerns and may be used to verify the accuracy of the tire pressure data transmitted by the TPMS sensors. This is accomplished by comparing the BCM tire pressure PID data to the actual tire pressure using a digital tire pressure gauge.

Training the TPMS sensors is not necessary  after a tire rotation on vehicles with the same  front and rear tire pressures. However, the BCM cannot recognize the sensor identifiers have been moved to different positions and retains the original position information for each sensor.