Is the TVA valve of EFI diesel vehicle always open?

It's not always on. Tva(throttlevalveactuator) is a device that controls the gas flow into the engine by changing the opening of the valve, and the gas flow into the engine is the largest when the opening is the largest. In the calibration, it is defined that when the tva opening is 0%, the intake flow is the maximum, that is, the valve is fully open; When the tva opening is 100%, the valve is completely closed and the engine may stop because there is no air intake.