Help? 1993 4l60e first only

[ChevyK1500]

Okay, so my 93 is giving me troubles again, it will not shift out of first. but all the gauges read fine and had it on the computer and no codes came up and showed the computer was sending the commands to the transmission for second and third but would never shift. I have no clue if it shifts into forth or not because we didn't have it that fast with the code reader on it.
The transmission shop here in town are not quite 100% sure on what the problem is and the are very well reputable. His best guess for now is a wire somewhere going to the transmission from the computer is cut or something. Could this be a reasonable cause for the problem? or the shift solenoid b? or could it be something else? Any help would be greatly appreciated as I am at a loss of what else could be the problem?
Thanks for the help in advance.

 

[cviola2005]

I'm gonna say that the 1-2 shift solenoid is stuck on. Try replacing it and see what happens.

 

[92GMC]

Try manually shift it?

 

[ChevyK1500]

I tried manually shifting it and it still wouldn't work out for me, it would still be in first. im thinking it possibly is the shift solenoid, and while I have the pan off is there anything else you guys would recommend replacing or upgrading? and im trying to keep from putting large amounts of money into the truck because i want it to be more of a budget truck, and i want to do as much work to it myself as possible so i know how it was done and i can be proud of it and say "yep, I did that myself" or "I built that part right there" and thanks for your guys input=)

 

[cviola2005]

fluid and filter.........

 

[rhino]

Unplug the wiring harness on the transmission. That will cut voltage to the solenoids, and put the transmission into "limp" mode. That will give you 3rd gear. If it still has low gear only, its an internal problem. If it has 3rd gear, then it would be electrical or in the valvebody. Also, when you unplug the harness, put the code reader on, see if it sets a few transmission codes. That will tell if the computer is seeing the break in connection. Could be a bad pcm. If you can pull up data on the code reader, watch and see if the pcm is getting the speed signal. Sometimes it will be getting the signal to the dash, but not to PCM.

 

[trx88]

i had an issue once with my vss sensor at the tailshaft and it did the same thing.