Test 9: Air Flow Sensor

Warm engine to operating temperature. Check that the sensor is properly installed and firmly seated. Ensure sensor plate moves freely. Pull back rubber covering airflow sensor connector. Turn ignition on.
Ensure voltage is present at Gray/White wire. If not, check related circuits. Measure voltage at Gray/Yellow wire. With airflow meter flap closed, it should measure less than one volt. As airflow meter flap is moved to wide open, it should steadily increase to about 5 volts. If not, replace airflow meter.