The 126 number just means that the part was first used in 126 cars and later "borrowed" for the 123s. EPC says "nothing found" for that number, sorry.

That cable might be from the throttle position sensor, which (I think) goes to the EGR computer, if your car has one.

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970