How to check the electronic valve servo motor of BMW X 1N20 engine?

After opening the cover, visually check whether the surface of the engine electronic valve is damaged and dirty, and also check whether the circuit is short-circuited with a multimeter. If there is no such phenomenon, there is nothing wrong with the electronic valve.

Overview:

BMW's engine with Valvetronic technology is the first engine without throttle in the world. "Valve" in Valvetronic means valve, "tronic" means electronic control, and Valvetronic can be translated as electronic variable valve.

This technology adopts BMW engine controlled by Valvetronic, and directly controls the intake volume by electronically controlling the opening depth of the intake valve. The opening depth is at least 0.25mm and at most 9.7mm, with a difference of 38.8 times.

Working principle:

The cam drives the rocker arm of the intake valve through an intermediate connecting rod with variable position. Due to this shape, when the intermediate connecting rod is deflected by an angle around the rotation axis, the valve stroke changes.

The middle connecting rod is driven by an eccentric wheel, which is integrated with the turbine and driven by a servo motor through a scroll bar. Therefore, the servo motor can choose the best value of intake valve stroke (between 0 ~ 0 ~ 9.7mm) according to the instruction of engine control system, thus improving power and reducing fuel consumption.