Truck started driving funny yesterday, if I set the cruise and let it pull a hill, the converter would unlock, Mini Max would say that it was unlocked, but 2-5 seconds later it would relock and be fine. Today it got worse until it now runs at approx 190-205 psi of line pressure even in neutral, and won't shift above 4th gear.
I tried to check for codes and the first time it wouldn't talk to the TCM..... Next attempt was engine codes, took 5 seconds to tell me no engine codes, tried the transmission codes again, took 5 seconds to tell me no transmission codes.
Rather harsh engagement due to the line pressure but otherwise shifts ok. Oil level is fine.

Did the controller puke or have I got another issue?

 

Did you talk to the dealer about that ?

 

Actually the last place I would take it to would be my dealer, ended up being a totally pooched trans...... completely rebuilt it and we're good to go again

 

It sounds like you're experiencing some serious transmission issues. The symptoms you're describing, like the erratic locking and unlocking of the torque converter and the high line pressure, point to a potential problem with the transmission control module (TCM).

It's a good idea to have a professional mechanic diagnose the issue. They can use a diagnostic tool to check for specific codes and pinpoint the exact problem.

Here are some potential causes:

Faulty TCM: This is a common culprit for the symptoms you're experiencing.
Faulty sensors: Faulty sensors can send incorrect information to the TCM, leading to erratic behavior.
Transmission internal problems: While less likely, internal transmission issues could also cause these symptoms.
It's important to get the issue diagnosed and fixed as soon as possible to prevent further damage to your transmission.