Originally Posted by feets
Since it's a throttle by wire system, it will have both a tps on the pedal and on the throttle. That's the minimum required to function. I'm not aware of two sensors on each end.
I spoke with one of my shop foreman and he's not aware of a Mercedes specific data logging system. However, he mentioned that one of the culprits that he's seen in this situation was a bad air flow meter. His experience involved vehicles with the exact same symptoms.
It's all in the manual. There is a description of the functionality following the failure of one of the TP sensors and here's the schematic - two TP 'pots' in the pedal and TB:
It is possibly a faulty MAF also, but again a standard OBDII logging session should pick that up, you wouldn't necessarily need an MB specific tool. You would see the abnormal fluctuation in the MAF voltage output. You may even see it with a multimeter.