I have a Peterbuilt 330 with an auto Allison transmission.
While driving, the check engine light comes on and the transmission sticks and won't shift up or down. I shut the truck off and it is fine again. Each time I try to drive it will not upshift and reverse doesn't work. Again if I shut off the truck and turn it back on, it drives for a mile then sticks again.
Any suggestions?
Thank you