Since your "not" getting the S displayed, when moving over to the sport mode, what indication due you get by bumping the lever over an over in the up shift direction, an then back over an over in the downshift direction. Upon bumping the lever the first time towards upshift, does the DIC display change over to the M mode as well as the gear now selected ? If that works, it would appear that the resistor bridge setup is intact. If I'm reading the W/D correctly, it shows that the lever bumps a switch to the closed position when moved over to the right column. Maybe that switch has a problem
So when P - R - N - D are selected, they are displayed as they should in the DIC, correct ? Since the shift lever is actually moving the shift link arm on the transmission thru those 4 positions, I think that means that the displayed gear position info in the DIC is coming from the transmission itself. I've never opened up the console area to actually see what items (switches, circuit boards, etc) might be in there, to interact with the shift handle once it is bumped over to the right. But it sure seems that the shift handle would no longer produce any action from the lower segment of the shift lever that's connected to the transmission shift position link arm. It would make me want to take an in-depth look at what that shift lever handle actually does, as it is moved thru its left/right/ forward/aft directions.
There is an 8 pin connector (that contains 6 wires) feeding all the electrical logic to that shift lever. Pin #1 wire brings 12 volts from the BCM to the switches that the shift lever works with (it is purple in color). Pin #2 wire goes from those switches back to the BCM ( it is purple/red in color). That same 12 volts from the BCM is also shown going to the cruise control circuit. If "it" works correctly, it probably means that you should have a good 12 volt reading at the pin #1 location from the harness section arriving at the lever. I think the wire going back to the BCM contains variable voltage values. Like when the lever is bumped to the right an each time an up or down manual shift is requested.
The 12 volts to the BCM was/is supplied by the F9 fuse in the I/P fuse box. But not sure how many or what circuits that fuse has control power over.