here's my amateur diagnosis.
ok, i know the transmission needs input from the VSS via the PCM in order to shift correctly. you haven't mentioned a shifting issue, so im going with the VSS is ok, and it's connection to the PCM.
so then im seeing only thing left is the connection from PCM to the instrument cluster, and the speedometer needle/coil itself (whose needle works exactly like the needle type multimeters)
scantool should be able to read vehicle speed via OBD-II link. does it show 0mph or correct vehicle speed?
since the PCM isn't throwing codes for not detecting vehicle speed, i think problem is in the display
does the odometer/tripmeter work?