TPM Diagnostic

After the Run/Start cycle and after initialization of the TPM, the TPM module registers a TPM Diagnostic when 1 or more tire transmitters are not transmitting. These transmitters start to transmit data after the wheel has reached 33 km/h (20 MPH.) Because the TPM module does not know vehicle speed, the BCM must ignore this fault until 70 seconds after the vehicle speed is greater then 33 km/h (20MPH.) This timer keeps counting even if the vehicle speed drops below 33 km/h (20 MPH.) After the timer has elapsed, the BCM will monitor the TPM module output for a fault. If the TPM module output returns to low for greater then 3 seconds, then the BCM will set the fault and after ten seconds, send a PCI Bus message (one or more sensors not operating properly) to the cluster. When the cluster receives this message, it will send a single warning alert request to the BCM and display the "Lo Tire" LCD message. If this fault has not set and the vehicle speed is below 33 km/h (20 MPH) for more than 15 minutes, then the 70 Second timer will be reset. If the fault has set since the last ignition on cycle, cycling the ignition switch will not clear the fault.