Turbo Bypass Valve (8/159) [2017-2022, B4204T27 | 2018-2022, B4204T28 | 2021-2022, B420T]: Description

The turbo bypass valve regulates the overpressure in the intake manifold. When the pressure is too high the valve is opened. The turbo bypass valve leads the pressure back to the turbocharger's inlet side. This maintains the speed of the turbo and allows the boost pressure to be immediately available.

The turbo bypass valve is electronically controlled by the Engine Control Module (ECM).