Air Temperature Sensor ( Ambient / Intake ): Description and Operation

Intake Air Thermosensor:

PURPOSE
Measure temperature of intake air and provide ECU with signal used in regulating fuel injection quantity, idle speed, and ignition timing.

LOCATION
In intake manifold runner.

OPERATION
Thermosensor is a negative temperature coefficient thermistor. This means as temperature increases, resistance decreases. Cold air is more dense than warm air. The ECU measures thermosensor resistance via a reference voltage to calculate intake air temperature.

TEMPERATURE / RESISTANCE (K OHMS)

68°F (20°C) / 2.2K - 2.7K
176°F (80°C) / 0.29K - 0.35K