By-Pass Control System (Legend)
Two air intake paths are provided in intake manifold. See Fig 1 . This allows ECU to select path length most favorable (power/performance) for a given engine speed. High torque at low RPM is achieved by using long intake path. High power at high RPM is achieved by using short intake path. These air paths are selected by ECU based upon sensor input signals. ECU controls by-pass valves in intake manifold through use of 2 by-pass control solenoids and a by-pass valve control diaphragm.