Exhaust Gas Recirculation (EGR) Cooler Bypass Valve
WARNING: This page is about a different car, the 2021 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.
The exhaust gases are directed through an EGR cooler by the EGR cooler bypass valve to remove heat before entering the intake manifold. The EGR cooler bypass valve is internal to the EGR cooler.
When the EGR cooler bypass valve solenoid is commanded to 0% duty cycle by the PCM, the EGR cooler bypass valve is closed. When the EGR cooler bypass valve is closed, the exhaust gases pass through the EGR cooler to the intake manifold.
When the EGR cooler bypass valve solenoid is commanded to 100% duty cycle by the PCM, the EGR cooler bypass valve is opened. When the EGR cooler bypass valve is open, the exhaust gases pass directly to the intake manifold without passing through the EGR cooler.