48re problems

[HRC]

I posted this on 911 a while ago and now have a update. I installed a master solenoid kit with a new gov solenoid mounted in a new billet piece. Starting the truck after the initial 8 ats of oil I got code P0868 low trans pressure. I figured it was caused by every thing being empty of oil Took a total of 12 qts to fill. Went for a drive it would start in second gear first gear didn't exsist Drained fluid and removed valve body again to see what I did wrong. Found nothing. Reassemble and drove it again. Going from reverse to drive it goes into first but as soon as you step on the pedal it shifts to second and will not go back to first. Any ideas?