My 17 2500 with the 68RFE trans went from running/shifting fine to not playing nice in about 200 miles. I have the MM3 and Rays tunes installed for about 4 months now, same time I had the Revmax TC and valve body with a new
solenoid installed.

So yesterday I was driving and anytime I was gong up a grade (not towing anything) 1-4 were OK but 5th and sometimes 6th didn't want to shift.

The TCC pid was jumping between hydro and locked constantly. I could ease off the throttle and it would lock up and drive fine once I flattened out. Also when freeway driving if I tried to pass the TCC would do the same thing.

When the TCC started jumping I got 2 codes and CEL P0933 and P0935. So I decided to call it a day and ease on home. 15 miles from home I get P0765 and all I have is fourth gear.

Tried clearing codes and letting it cool down some but that did nothing. My buddy came with a trailer and we took her home. We get to my place and I start it up to limp it into the driveway and it goes right into drive fine. Made 4 or 5 laps around the neighborhood just fine no codes.

I'm thinking since the original codes were pressure related the sensor may be going and that is throwing the TCM off and causing the TCC to jump around.

Any advice or suggestions would be greatly appreciated.