[CREWZIN]

I did a fast search and there was one that I found that was near to your problem. One of the answers was from someone that seemed to know what he was talking about.

The trans module can store codes and they need to be read to see if any
exist and then go from there. Clutch volumes need to be carefully looked
at.
Did the battery get disconnected for any reason? This could have wiped
out the pinion factor and it needs to be put back into the t.c.m since this
tells the controller what size tire and rims are on the car and this can
mess with shifting.