I replaced the upshift delay valve. It has I think a green line and black line going to it. The green line is the vacuum, and it connects to the transmission. The black line is electrical.
Somewhere, someone has posted a picture of this (maybe it was Arthur Dalton). He's the Lone Ranger when it comes to these fault code diagnostic issues.
2001 E430, Bourdeaux Red, Oyster interior.
1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".