Kia Optima: Intake Air Temperature Sensor (IATS). Description and OperationTo calculate precise air quantity, correction of the air temperature is needed because air density varies according to the temperature. So the ECM uses not only MAPS signal but also IATS signal. This sensor has a Negative Temperature Coefficient (NTC) Thermister and it's resistance changes in reverse proportion to the temperature.

Installation
Intake Air Temperature Sensor (IATS). SpecificationsCircuit Diagram
...
Front Impact Sensor (FIS). Components and Components Location
Components
...
Specifications
Specifications
Items
Specifications
Rated voltage
DC 12V
Operating temperature range
-30°C ~ +80°C (-22 ~ +176°F)
...