what is a scv valve
Making the world better, one answer at a time. Nissan's swirl control valve (SCV) is an actuator that modulates intake air flow into the engine to increase low and high engine speed efficiency.The SCV does this by constricting the intake opening during idling and low engine speeds.nswered by The Community. Making the world better, one answer at a time. Nissan's swirl control valve (SCV) is an actuator that modulates intake air flow into the engine to increase low and high engine speed efficiency. The SCV does this by constricting the intake opening during idling and low engine speeds.