So I did some reading on here and everything Ive seen Ive tried.

history, 98 expedition with a 4.6 and 4r70w trans.
beginning of the year it had a trans issue, lost pressure i believe. wouldnt ingage 1st gear til a high rpm and once in gear and moving it wouldnt go into OD on the highway at times, once it finally did it would slip.

a local shop rebuilt the tranny for a decent price but now im seeing why it was at a decent price.

so now the tranny is having issues again, its stuck in 2nd gear and doesnt shift out. I ran the CEL and got code p0750 which is shift soleniod a
I replaced it and the code came right back after a few key on cycles.
so further research I found the plug damaged (pass side of trans above pan) it was missing a pin inside the plug. so I ordered a new PLUG and internal soleniod harness, (dropped valve body to install it) installed the plug and internal harness and spliced in a new outside white plug (7 pin plug) wrapped it back up. drove it around and the code (s) came back now I have soleniod A and B (p0750 & p0755) codes.

Im not sure where to go from here on fixing the problem.

things Ive noticed, starts in 2nd gear, doesnt shift from second gear and the shift lever on the column doesnt manually shift the trans.

I went ahead and ordered another shift soleniod pack and tcc sensor to see if maybe I recieved a bad one.


any other info or tips to try would be awesome


Thanks
Tyson

 

I would ohm the whole harness out all the way from the transmission to the comptuer. Make sure that you see the correct readings at the computer for the solenoids with the transmission plugged into the harness too. That will help you isolate it.

Darrin