My truck didn't want to shift out of first gear the other morning and wouldn't go into lockup in fourth gear no codes right away. Come out after work now have P1762 so I ordered solenoid, pressure sensor, speed sensor, filter, and gasket kit. Switch out parts refill take for a spin at first everything seemed fine when tranny warmed up I get code p0868 and truck is starting in second unless I go to neutral then 1st and shift manually. If I clear the code it's fine for random number of miles usually 2 or 3 then code pops up and same problem. I dropped pan a second time to check all connections and wiring all seems fine. I am leaning towards a bad pressure sensor I've read where people say they get bad ones any idea thoughts.

 

Replaced solenoid, sensor, and lockup solenoid/ wiring harness truck is fine till i hit 40-50 mph then code p0868 low line pressure and when i stop will start in second unless i manually shift to neutral then first. Tranny doesn't get hot runs fine except trips the code and starts in second gear any other ideas?