I respectfully disagree on the advice that you may have a bad engine wiring harness.
This site and others on the world wide web are full of posts with owners of E320's and C280's with bad engine wiring harnesses on M104 engines (2.8 and 3.2 liter) from '93 and '95. They are all bad.
I have also read many posts on this site about many bad engine wiring harnesses on '92 - '93 400E's.
If you do a search, you'll find well over a hundred posts on this site, and 80-90% of the complaints are M104 engines, and maybe 20% are M119 engines.
But I can't ever recall, not once, reading or hearing of a complaint regarding a bad engine wiring harness problems on M111 engines.
There may be some problems, but I'm inclined to believe it is very rare, and you'd be the exception, not the rule.
2001 E430, Bourdeaux Red, Oyster interior.
1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".