Circuit Operation

Approximately 5 volts are applied to the intake air temperature sensor output terminal (terminal No. 6) from the ECM (terminal No. 72 - M/T) or PCM (terminal No. 64 - A/T) via the resistor in the ECM (M/T) or PCM (A/T). The ground terminal (terminal No. 5) is grounded with ECM (terminal No. 40 - M/T) or PCM (terminal No. 16 - A/T).
The intake air temperature sensor is a negative temperature coefficient type of resistor. When the intake air temperature rises, the resistance decreases.
The intake air temperature sensor output voltage increases when the resistance increases and decreases when the resistance decreases.