1996 Powerstroke trans codes p708, p1748, p1728 help?

[cubid1997]

Hey guys second powerstroke Ive owned here its a 1996 Ford F350 7.3 turbo diesel and the tranny is experiencing some issues. The issues i am having i had the codes pulled by a local tranny shop and he came up with the following codes, P708 neutral safety switch, P1748 epc fault and lastly P1728 tcc slip.. The trucks over drive light is flashing and when he checked it he earased the codes and when i left the shop the trucks tranny shifted nice and smooth and not hard shifting into second and so on and as soon as i went on the freeway 20 min after he took the codes out the problem came back ovedrive light came back on and the problems came back. The problems i am having is the truck bangs going into second. It does NOT slip at all . The tranny bangs going into second and slight bang into third. If i turn the tuner on to about 75 hp and take off a little agressive the bangs is not noticeable. I have read on here at some other peoples ideas and all but based on what i said what do you guys believe it could be ?
Also jasper located in Massachusetts had put a new tranny in the truck and when the kid i bought it from got the truck the problem begain with him.. he replaced the valve body in the tranny. After he did that the truck still had the problem and so he replaced the tranny with one that had 100k on it odly when all said and done the truck with the other tranny still continued the problem. PLEASE HELP! thanks

[cubid1997]

Does Anyone know or experienced these problems and can tell me what to replace or do ?

[STROKED_NY_023]

Check the plug... Sometimes the wiring harness to the trans can get corroded, or burnt. Also was the shift solenoid replaced?? Did you say you took it to a trans shop?? They couldn't give you any ideas?

[sgt dave]

I had a p1728 code in my old tranny and it was slamming into gears like yours. I was told that since your tcc is slipping the valve body is trying to make up for it by raising the line pressure that's why it's slamming into gear. So I bought an ATS trans and 5 star tcc and no more tranny problems.

[cubid1997]

All I did at the tranny shop was run the codes for me and try to tell me what is best to do and all.. My torque converter doesn't feel like it's slipping at all though.?

[cubid1997]

Shift soilenond as far as I know was not replaced im going to try and replace the neutral saftey switch the speed sensor on the rear end and on the tranny and clean the plugs have the codes cleared and if that dont work I guess I will have to wait till
My tranny blows

[cubid1997]

And can anyone send me a picture of there tranny plug te main one so I can see where the prongs are and all?

[cubid1997]

hey guys i noticed today i have a body to frame ground strap broke will this affect anything?