ignore this duplicate post

[fairdeal]

I'm very familiar with the simple epoxy-potted plastic case of my F225 ECM-

so I was taken aback yesterday at seeing the ECM of a 2006 F90


> what is the purpose of that "button-like gizmo"?


the only thing I can imagine is that there is "air space" within the case

and that is some kind of vent...