Sub-System Description and Operation

Swirl Control Valve System:

CIRCUIT OPERATION
The swirl control valve (SCV), located in the intake manifold passage, partially closes off the intake passage of each cylinder at idle, restricting air flow. This causes the velocity of the intake mixture to increase, promoting better vaporization of the mixture. This increase in velocity makes the fuel mixture burn faster, increasing fuel economy and engine stability.
During all other operating conditions the SCV opens allowing the intake flow to encounter less resistance, improving power and acceleration. The ECU supplies the ground circuit to the SCV solenoid, cutting the vacuum source to the SCV. This allows the SCV passage to open, thereby allowing non-restrictive air flow.

Fig. 30 Solenoid Valve:

SWIRL CONTROL VALVE SOLENOID
The swirl control valve (SCV) solenoid allows vacuum to be applied to the SCV. The ECU completes the ground circuit allowing battery voltage to operate the solenoid.