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). SpecificationsRelay Box (Passenger Compartment). Components and Components Location
Components
...
Ignition Switch and Anti-Theft Steering Column Lock
Ignition Switch Positions
LOCK
The steering wheel locks to protect against theft. The ignition key can be removed
only in the LOCK position. When turning the ignition switch o the LOCK position, ...
Installation
In the case of the vehicle equipped with immobilizer
or button engine start system, perform "Key Teaching" procedure together
...