The code you are getting is from a breather that can clog. If memory serves....and it has been years since I turned a wrench on an M111, you will see a brass looking canister the size of a small childs fist at the rear of the engine above the transmission tunnel. It gets clogged and the lack of vacuum causes the trouble code.
Feel free to critique my input, but this is how I recall clearing that trouble code after many resets.
'02 C230 Coupe Mods by preference
* Bi-Xenon Lights *
* AMG Brakes *
* Kleeman Pulley *
* H&R Cup Kit *
* AMG 203 17" Staggered rims *
* Supercharger Ported by Stiegemeier *