Tire Pressure Sensor Learn Learn Mode Description The tire pressure monitor (TPM) system uses the passenger door module (PDM) , body control module (BCM) , exterior lamp switch, 4 radio frequency (RF) transmitting pressure sensors, and the serial data circuit to perform the sensor learn mode functions. The sensor learn procedure must be performed any time the PDM is replaced, a sensor is replaced, or after the vehicles tires have been rotated. Once the learn mode has been enabled each of the sensors unique identification codes can be learned into the PDMs memory. When a sensor's Id code has been learned, the PDM sends a serial data message to the BCM to sound a horn chirp. This verifies the sensor has transmitted it's Id code and the PDM has received it. As soon as the fist sensor Id code is learned, all other Ids are erased from the PDMs memory.Sensor Functions Each sensor takes a pressure measurement sample once every 20 seconds while in stationary mode. If the tire pressure increases, or decreases by more than 11 kPa (1.6 psi) from the last pressure measurement, another measurement will occur immediately to verify the change in pressure. If a pressure change has indeed occurred, the sensor sends a re-measure transmission to the PDM. When the PDM receives a re-measure transmission while in sensor learn mode, it will assign that sensor Id to that location on the vehicle.Sensor Location The PDM must learn the sensors Id codes in the proper sequence in order to determine sensor location.Learn Mode Cancellation The TPM system will cancel the learn mode if more then 2 minutes have passed and no sensors have been learned, or if the system has been in learn mode for more than 5 minutes. If the learn mode is canceled before any sensor has been learned, the PDM will remember all current sensor Ids and their locations.Important: Before proceeding with the steps below, ensure that no other sensor learn procedure is being performed simultaneously, or that tire pressures are not being adjusted on a TPM equipped vehicle within close proximity.