Changing gears when using the gear shifter is always done mechanically.
What it electronic is how long it holds is up and down shifts.
Sport mode holds up shifts for longer and down shifts easier for a "sporty" feel.

 

Ha sport mode I used that for a couple days when I first bought the truck until I noticed how much more gas a "sporty" brick burns.

 

Sounds like a speed sensor/electrical problem to me. If the transmission feels solid (no slipping) in L1 L2 L3 etc. In (manual-mode) your telling the computor what to do... btw does the speedo work? I would take a chance if it was under 1000.00 or so..

 

Spedo works..... no slipage...drives fine shifting it manually.....Thanks again