The basic TPM system alerts drivers when tires are underinflated through a warning light on the instrument panel. The enhanced TPMS system locates the underinflated tire(s) and displays individual warnings.
Direct TPMS solutions comply with Federal regulations in the US and European customer requirements. Keys to the system are a battery-powered Remote Frequency sensor that is deployed in each wheel, and a receiver that retrieves tire data from each of the four sensors. Direct TPMS, unlike indirect TPMS, measures true tire pressure, so there are no error factors or inaccuracies due to calculating other indirect pressure measurements, such as wheel rotational speed.