Air Flow Meter/Sensor: Description and Operation

Burn-off Control System:

The airflow sensor is equipped with a self-cleaning feature that momentarily super-heats the hot wire to burn off contaminants that may have collected on the wire. The burn-off occurs after the engine has been stopped (ignition switch off), and the following conditions are met:
a. The engine has run more that 1,500 rpm for 5 seconds after warm-up.
b. More than the prescribed amount of intake air has passed through the airflow sensor since the previous burn-off operation.
The computerized engine control related components of the burn-off control system are the airflow sensor, engine control unit (ECU), ignition coil, and the water thermosensor. The ECU receives inputs from the ignition coil and water thermosensor and determines when the hot wire in the airflow sensor needs cleaning. When this occurs, an 8-12 volt signal is sent to the green/orange wire (terminal 2K) of the airflow sensor connector 2-5 seconds after the ignition switch is turned off.