Have been through details many times but my scanner is able to drill down far beyond the ODB-2 details, and the Autel Diaglink is the least expensive scanner ($88 with coupon on AZ) I've found that can do so and export results to a PC. No lights or top level codes found since I fixed the BAS/ESP/
The N54/3 is not in the service manual but in a Mercedes document I do not have. Is it downloadable ?
I have a remote testing device and a green light comes on when pressing lock or unlock in the 300-320Mhz range.
Have a red ring I hold on the dash keyhole that a diode flashes when the car reads the chip. Works fine in SLK but does not flash in coupe.