Relief Valve
The relief valve is used to reduce the noise shocks when you let up the accelerator quickly while driving.
The valve is an electro-magnetic valve which is supplied with voltage from the system relay. When the valve is to be opened the valve is internally grounded in the Engine Control Module (ECM).
The valve is closed when in the standby position (open-circuit).
The relief valve can be diagnosed and activated (open/closed) using the diagnostics tool.
Also refer to FUNCTION
The relief valve is located on the turbocharger's housing.