I am trying to get an ECU from a 518AF AMB to work with a car that originally had a 518F. Per the diagnostic errors reported, there seems to be some differences in the DBW and brake booster wiring. At this point, I really need the ECU pinouts from 2002 and 2003 from Bentley to compare.
I have the Bentley at home, and I've mapped out all the pins in a notebook to assist me when I order the materials to make my own custom harness. I can post my notes when I get home from work tonight.
However, the only wiring difference I'm aware of is for the vehicle speed sensor that the 518F uses, located on the transmission just above the driver's side axle.
The 518AF and 518AK do not use this sensor to determine vehicle speed. Instead, I believe they receive individual wheel speed signals, or maybe an average speed, from the ABS module or the instrument cluster via the CAN controller.