Solenoid Valve
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 solenoid valve. Apply air pressure to port "B". Air should flow from "C". Using jumper wires, apply battery voltage to solenoid valve terminals. Apply air pressure to port "B". Air should flow from port "A". Replace solenoid valve as necessary.