@Mick Briesgau that Difference Pressure Sensor (Differenzdrucksensor) is very liable to make mistakes, in all of my Merc Diesels (from E to S, from 4 Cyl to 5 Cyl) i ve changed them nearly 3 times so far.
When that Part gets defective it puts your car in to safe mode to protect your engine from damage.
You lose power and the transmission works faulty. Since that part is cheap (about 70 Euro) and easy to exchange its not really a big disaster.
The Problem is how the Mercedes Garages deal with it.
I was always told that my Diesel Particle Filter was full and that it has nothing to do with the Sensor.
Its the other way around, when the Sensor is faulty, it fills up the Diesel Particle Filter and replacing that is very expensive.
So i went to an expert, he changed that sensor and wished me luck - that the Diesel Particle Filter would regenerate again.
And Mick, a friend of mine invited me to drive his S 500, the longer i drove it - i loved it more.
After returning to my 730d it took me 2 days to love it again
Okay you cant compare a Diesel to a S500 but... that atmosphere in that S500 - respect nice done Merc.