Intake Air Temperature Sensor (IATS) is NTC thermistor which voltage gets low if the temperature comes to be high. One is installed inside of MAFS and the other is installed between BPS and intercooler. It senses intake air temperature. In case of EURO-5 diesel engine, IATS is installed in front of turbocharger (inside of MAFS) and behind it (between BPS and intercooler). Comparing air temperature from both sensors (one is intake air temperature, the other is air temperature passing through turbo charger), more accurate sensing of intake air temperature is possible. With intake air temperature signal, ECM performs EGR control correction and fuel injection quantity correction. (MAFS is needed for EGR FEED BACK control in electronically controlled diesel engine.

The calculation of air density at certain temperature is required to perform EGR FEED BACK control correctly.)