Hi,
I noticed that this f problem is so common, i have to share my experience with it.
We have A160 automatic and there was strange things in tranny: huge gap between 1 and 2 gears, and all other gears went on and off without anykind of logic, every now and then F on dashboard. I took the car to local mb dealer for normal service and asked them to look transmission at the same time, if there is something wrong...when i picked up the car from dealer they said it can be fixed but costs will be lot..hmm..we booked new time for tranny repair.
Here`s what they did to it:
changed electrohydraulic control unit
changed some other ? control unit
changed transmission oil and filter
adaptation reset
costs 2250€
well, costs were huge, but now it runs so very smoothly

I don`t know if love or hate this car.....