XT-6 2WD L6-2.7L SOHC (1989)
Air Flow Meter/Sensor: Description and Operation
Air Flow Sensor
PURPOSE
The air flow sensor measures all air entering the engine through the intake system. This information is vital to the ECU to determine proper fuel
mixture and ignition control configurations.
LOCATION
The sensor is mounted to the air cleaner box in front of the right strut tower.
CONSTRUCTION
A hot-film sensing head is used to measure air flow. Air flow is measured by determining the cooling effect on the sensing head.
OPERATION
Whenever the ignition is ON, the sensor produces an output signal to the ECU. The hot-film sensing head acts as a temperature sensitive resistor.
The ECU maintains the sensing head at a preset constant temperature. As air passes over the hot-film, it has a tendency to cool. Since the sensor
head changes resistance based on temperature, a varying current is required to maintain constant temperature. The internal circuitry of the sensor
monitors this changing current demand and sends a varying voltage output signal to the ECU, tracking current required.
