Circuit Description
WARNING: This page is about a different car, the 2003 Toyota Tacoma. However, it is still accessible from the selected car via links, so may be relevant.
A 5 volt power source voltage in the ECM is applied to the intake air temperature sensor from terminal THA via a resistor R (resistor R and the intake air temperature sensor are connected in series). When the resistance value of the intake air temperature sensor changes in accordance with changes in the intake air temperature, the potential at terminal THA also changes. Based on this signal, the ECM increases the fuel injection volume to improve driveability during cold engine operation.