1996 E-150 Econoline transmission jump

I have a 1996 E-150 Econoline, sometimes when I’m driving and do a rolling stop when I give it gas it’s like the transmission is in neutral and then jumps into gear it only seem to happen if I had it up over 60mph but once you come to a complete stop it’s fine. Took it to a transmission shop $16.000 later it’s still do it.

I'm having a similar issue with the trans right now but for me it's when i'm slowing to a stop. it's like the trans wants to keep puling the van as I have my foot on the break until it bogs the motor down and stalls out. I'm trying to find a solution here and it looks like the speed sensor may be the culprit. I'm not sure tho. Did you have a flashing OD light? If so it means theres a code that can be read to help diagnose the issue.

--Anyone know where to get a list of the codes so I can diaganose it myselfe?