RCV (Recirculation Valve) Control Solenoid Valve is installed on the intercooler inlet pipe and operates the RCV actuator which controls the by-pass passage of the turbocharger compressor.

When the throttle is closed, while the engine is running at cruise rpm (tip-out), the turbocharger boost pressure raises rapidly.

The pressure wave strikes a compressor blades causing a knocking noise. To prevent this the PCM opens the recirculation valve which allows excessive boost pressure to vent back to the air cleaner side of the turbocharger compressor.