e320 cdi w211 gearbox issues pleeeeez somebody help!
I bought the car without test driving first because it was cosmetically damaged. I have sorted all that out now but the car is just not driving right

When i put my foot down there is a distinct lack of power. But more worrying than this, is the fact that the car doesn't go through all the gears properly. It does 1st to 2nd ok but when it goes to 3rd, the revs drop down to around 1500rpm and when i try to accelerate theres nothing! Theres no kick down too! This is accompanied with a slight vibration in the cabin.
Somebody told me to get the gearbox oil and filter changed, which i just have. Now when i drive it the vibration is less but all the other symptoms are there.
My mechanic used some sort of snap on scanner to determine the problem and it keeps on firing back a code "P0800" which i believe is 'Transfer case control system"
Can somebody please tell me what this means and any other ideas or suggestions to what i should do next...



