Working on my friends 2005 2500 with 228k . Transmission stays in limp mode. For a while after I after the truck arrived at my shop it would shift fine for approx 10 miles then shift into and stay in limp mode. I could then stop and turn truck off and it would go thru one shift cyle fine and then go back and stay in limp mode. Codes were p0602 and p2769. We have checked alt., batteries, connections, grounds, changed pressure transducer and Trans control solenoid. At owners request we just installed a new computer. HELP.. Anybody experienced this??

 

The only time mine went into limp mode (2006) was when the fuel filter was plugged, could not get enough speed to even shift, changed filter on the side of the road and she was good to go after a short time, hope you get her fixed.