How Tire Pressure Monitoring System (TPMS) Works
Direct TPM systems consist of:
- Pressure Sensors - A small battery operated device that measures air pressure. Sensors are generally attached to a valve stem but may be separately strapped to the interior well of the wheel. Coded data including sensor ID, pressure and temperature may be transmitted to the Electronic Control Unit (ECU) at 315 Mhz or 434 Mhz Radio Frequency (RF).
- ECU Receiver - This is generally a dedicated unit that receives the Pressure Sensor transmission data.
- Body Control Module - Communicates data from receiver to dashboard or display panel.
- Malfunction Indicator Lamp (MIL) - A light on the dashboard that indicates TPMS malfunction. A solid lamp indicates low tire pressure or a faulty sensor. A blinking lamp indicates a system malfunction such as the sensor and ECU are not synchronized, or it may indicate a fault ECU.