I have 2010 dtc P0101 I have looked at every thing and still can not get rid of the problem, I have to be over looking something BUT WHAT!
This can be a bit of a challenge at times to trace, especially if you don't have specialist auto mechanics equipment.
Basically the PCM is telling you the charge values are out of whack.
It starts aft of the turbo where charge out leaves the turbo on its long and arduous route to the other side of the engine and then back up again to the inlet manifolds.
The dog leg alum tube and its seals, plus that ill conceived silencer and all the adapter sleeves & seals are very prone to leaks. (leaves me at times to think what brainiac came up with that idea.)
Now down to the rest bend hoses that connect to the cooler (yes "rest bend" like the porcelain commode in your house) Prone to rupture and worn split O rings, these things are a very high on the list of leakage points. In college in France the teaching was putting an omega bend in a high flowing pipe was a no no mon sewer! Basically P trap!
Of course I won't mention the intercooler yet (being a bit sarcastic) because it has a nasty habit of leaking at the end tank seals.
Then its up and under to the throttle body passing an O ring plus gasket where there is a charge pressure sensor and then onto a mix of O ring and gasket where the whole snaking arrangement meets the manifolds proper. Phew! whatta trip!
Now normally a regular low pressure smoke machine can find leak points but with these machines the recommendation is to pressurize the whole inlet arrangement with 30 psi of shop line pressure.
By the way I see that the pro tool suppliers like Snap On are releasing high pressure smoke machines that deliver 30 psi for us in the trade at grandiose prices.
Now in practical terms I had one last week that would only fault out occasionally and it seemed that it always happened on steep grade once in a blue moon. So it was obviously a high pressure leak.
It was ultimately traced to a leak in the intercooler end tank seal using 30 psi of shop line pressure. A new cooler and hoses fixed it!
By the way P0101 equates to MB code DTC 150200 and includes 14CF00 referring to EGR component Y27/17.
And that my dear friends includes a sticking EGR valve and blocked up EGR cooler.
Now that last week's specimen had the same info pop up on my scanner screen but I preferred to concentrate on the charge air system which eradicated all the faults. Lady artist owner reported a subsequent trip to Chicago from Denver showed no faults by the time she was in Davenport Iowa.
All happy campers.
Hope that gives you some pointers!
Dennis