The boost pressure control flap has a malfunction
 

Hey, this is my first poat in this forum, i hope i get your help,

I own a W204 2008 c200 1.8L
My check engine light came on my dashboard, and some times the the loses torque and it get back to normal when turning it off and restarting it, mechanics tried to solve the problem but it keeps returning

I get this error on computer check

The boost pressure control flap has a malfunction

My mechanic replaced the pressure sensor and the pressure flap in the compressor, the check engine light went off on its own and the issue was solved for a day, at the end of the day the light kicked in again,

Note: i noticed that the boost pressure sensor was drowning in engine oil when we tried to replace it, is that normal?

Here is the sensor i changed
https://cimg3.ibsrv.net/gimg/www.mbw...9f30e79b02.jpg


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Here is the computer errors , they are the same on star
https://cimg6.ibsrv.net/gimg/www.mbw...206eb7b152.jpg

I had this problem, same 2 codes plus one about engine speed "the output signal for engine speed has short circuit to ground" even though rpm was showing correctly.
I replaced the boost control flap electronic throttle body but the problem didn't go away.
Anyways i was checking values in xentry and i saw maf was reading 0..wtf..i check no power there..i check fusebox and found n.22 15A fuse blown (looking online it's labeled "engine electronics"), replaced it and all fixed now. 0 problems, 0 codes.
It probably supplies the h-bridge for the ETB; i didn't open it to check if is shorted and blew the fuse..
So if you have this problem, check for the fuse first before spending money and pain to change it.

So i leave this solution for anyone to find.

edit: also mercedes has stupid error codes, design is very bad..it should give error for all sensors powered by this fuse but it doesn't..FAIL