Air intake temperature sensors, or IAT sensors, work by analyzing and recording information through a computer in the car to determine air density. The amount of air density in turn helps sensors maintain a correct fuel mixture ratio. The computers to which IAT sensors connect adjust air intake and fuel ratio according to feedback received from the IAT sensors.
IAT sensors are small parts of the engine and fuel systems. They often connect with mass airflow sensors, called MAF sensors. MAF sensors control airflow entering the engine by quantifying air volume and density. IAT sensors are located on air intake tubes, along the intake manifold or even in the MAF sensors. Although they have separate functions, these sensors play a large role in helping engines run smoothly and maximizing fuel economy and car performance.
As with other car problems, drivers receive indication when IAT sensors need repairs. Problems with these sensors prompts the check engine light to illuminate. Sometimes, drivers notice poor engine performance and stalling, especially in colder weather, when sensors begin to fail. Common causes for IAT sensor failure includes prolonged exposure to excess engine heat and exposure to debris, which can accumulate on the surface.
To identify problems, drivers can check the temperature reading on the sensors to the temperature reading of the engine coolant thermometer after letting cars sit for 1 hour without running; the two temperatures should match or come close to matching.