Air By-Pass Valve (ABV) Actuator
WARNING: This page is about a different car, the 1997 Mazda Millenia. However, it is still accessible from the selected car via links, so may be relevant.
Remove ABV actuator. See Figure . Verify air does not flow from port "A" to port "B". See Figure . Connect a vacuum pump to ABV actuator port "C" and apply 10 in. Hg. Air should flow from port "A" to port "B". Airflow should increase as vacuum to port "C" is increased. If ABV actuator does not operate as specified, replace ABV actuator.