We plug into the DSC button with a mating connector just like stock. We plug into the DSC harness connector with our harness adapter. We wire our LED-illuminated pushbutton for Sport mode. We wire the Sport mode output (SO) to pin 15 in connector X60004. We wire the cluster lamp output (CL) to pin 8 on connector X17.

The info I have from the M3 (hardcopy from the dealer system) is that the wire to pin 15 on the DME is SW/RT/GE (black/red/yellow).