Air Flow Meters

Theres a test for them to see if they are faulty..

Using car bettery voltage 12V..

Put + onto pin B, put - onto Pin C.
Then put your multimeter red lead onto d and the black lead to - side of battery.

With no airflow you should see apprx 1V from Pin D to - side of battery.

Whilst holding the multimeter on pin d and - side, blow air through the AFM, the voltage should vary from 1V up to about 3V.. if it does, it works ;)