bmw e46 325xi electric solenoid valve in vacuum line

On the F10 it is now reverse where vacuum applied means the exhaust flap is opening

This causes the exhaust gas to pass through the long resonator pipe, reducing the low frequency noise that is generated. Where at idle speeds, up to 2500 RPM: the exhaust flap is closed with vacuum applied to the actuator. Of the exhaust flap operation is controlled by the MS 41.1 module. The basic system was initially introduced on the E46 platform and the electrical function To disconnect the pump via the electric connector in the trunk to keep the valve open).

It is operated by a vacuum pump underneath the trunk (a common mod on the E90s is The valve is part of the BMW Active Exhaust and is purely for noise reduction. I looked at a schematic of the exhaust on and there is an in-line electronic value farther up the vacuum tube which may control whether or not the exhaust valve is 'active' based on certain settings or other conditions, but I do not think it can actually control the valve itself. From moving them by hand I can tell you it's a fairly stiff spring, so a lot of pressure will be necessary - likely once the engine is above something in the 5,000 to 6,000 RPM range. Again, I may be wrong, but I do not think either of these is correct since there is no electronic control of the valves - it appears as if the valves can only be opened by sufficient pressure built up in the vacuum line.

I had read some comments in this and other threads that the valves open when the cats warm up or Sport+ mode is selected on the throttle control. Based on my visual inspection, the only thing leading to the actuator that controls the valve is the vacuum line. I'm by no means an expert, but I spent some time playing around with the exhaust valves the other day.

Bmw e46 325xi electric solenoid valve in vacuum line