The problem I had was the black cable coming from the module (which is buried in the well in the fiber pad below the sensor grid).
At the point where it was zip tied to the frame, the wires had internally fatigued. Not easy to see from outside the black jacket but I had a hunch so I carefully sliced the jacket off and sure enough it had the classic fretting failure just like what happens on the door harnesses.

Rant: can they not get this right? I work in industrial controls, we actually have it specified in the UL/ANSI product standards for our work that if we have a wire crossing a flex point it has to be a high strand count wire...this is such a common problem with MBs and their low strand count wire. Sorry just a total pet peeve of mine.

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The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech