In Air Flow Meter/Sensor

Air Flow Meter:

Incorporated into the airflow meter is an intake air thermosensor.

The thermosensor is a negative temperature coefficient thermistor. Negative temperature coefficient means as temperature increases, resistance decreases. Cold air is more dense than warm air. The ECU measures the resistance of the thermosensor, calculates the temperature of the incoming air, and uses this information to help regulate the following:

^ Fuel injection quantity
^ Idle speed control
^ Vapor canister purge control

Sensor resistance is checked at airflow meter terminals "E2" and "THAa":

TEMPERATURE / RESISTANCE (K OHMS)

-4°F (-20°C) / 10K - 20K
68°F (20°C) / 2K - 3K
140°F (60°C) / 0.4K - 0.7K