2017 GLS550 Turbo A Underboost CEL

[kevm14]

Yes and the lever being perpendicular to the engine at closure gives the actuator the most lever arm to close the valve. I don't know what the exact inner geometry of the vacuum can is but it may also have a position that can exert the most force. And that might not be the beginning or end of travel. I assume it just depends on where in the travel exposes the most diaphragm surface area for the vacuum force (meaning atmosphere) to act on.