LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Subaru >> 2003 >> Outback Base, 4D Sedan >> Repair and Diagnosis >> Engine Performance >> Theory and Operation >> Engine Controls - Theory & Operation >> Air Induction Systems >> Induction Control System
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Induction Control System

There is a butterfly valve on the partition between the intake manifold's right bank and left bank chambers. This valve is operated by the induction valve actuator installed on the intake manifold. During operation of the engine, pressure waves are generated in the intake manifold. The pressure waves have an effect of improving air intake efficiency. To make the most of this effect, the direction of the pressure wave is changed by opening and closing the induction valve in accordance with the engine speed so that increased engine output torque is obtained in all speed ranges.

Fig 1: Identifying Induction Valve Open & Closed (Outback 3.0)
G00166698Courtesy of SUBARU OF AMERICA, INC.