If the valve is not being controlled by the ECU then the ECU has failed, It is not repairable.
That IAC does not step open and stay open on that valve design, it is a pulsed ground signal that controls it. You can test the valve by making sure it has power to one side, connect a wire to the other terminal and tap the wire on a good ground, you should be able to hear the valve move.
That engine also has a second high idle control, that is a mechanical unit with a wax pellet inside. If it has failed open the other valve may not be able to control the idle.
Wednesday, December 28th, 2016 AT 10:58 PM