Hyundai Sonata LF: Engine Control System / RCV Control Solenoid Valve Description and Operation
RCV (Recirculation Valve) Control Solenoid Valve is installed
on the cooling pan motor top and operates the RCV actuator which
controls the by-pass passage of the turbo-charger compressor.
When the throttle valve is closed during engine running
[Tip-out], crash noise of the impeller will occur because of rapid
increasing of the boost pressure. So, in this case, in order to prevent
this phenomenon, ECM maintains the appropriate boost pressure by opening
the by-pass passage.

Inspection
[Motor]
1.
Turn ignition switch OFF.
2.
Disconnect the EWGA connector.
3.
Check that the EWGA is stuck by foreign material.
4...
Other information:
Inspection
Self Diagnosis with Scan Tool
It will be able to diagnose defects of SMART KEY system with
GDS quickly. GDS can operates actuator forcefully, input/output value
monitoring and self diagnosis.
The following three features will be major problem in SMART KEY system...
C..