Intake Air Temperature Sensor

PRINCIPLE OF OPERATION, INTAKE AIR TEMPERATURE SENSOR






Intake Air Temperature Sensor--is of NTC type and located in the intake manifold before the throttle. The control module measures the air temperature in the intake manifold by applying 5 V to the sensor from pin 46 via a built-in 2.74k ohms resistor. The sensor is grounded via pin 67, The voltage across the resistor in the control module is proportional to the intake air temperature.

This voltage is used together with the pressure in the intake manifold to determine the density of the intake air and consequently the engine load. Fuel injection duration is proportional to the engine load.

If the sensor is unserviceable or if there is no continuity in the circuit the control module will use a default temperature of 8°C and the CHECK ENGINE malfunction indicator lamp (MIL) in the main instrument display will light up.