pulling fifth wheel up mountain. Truck shutters, loses power and engine light comes on. Can't drive over 10 mph. Took to dealer error code P2764. Dealer replaced valve body and harness in aisin transmission. Truck did the same thing after picking it up from the dealer. Now dealer says it is a bad torque converter. What do you think?

 

C codes are chassis codes...... I find a couple different descriptions for that one, but, nothing really meaningful. Information for that is rather lacking. Transmissions faults should generate P codes. (powertrain) So, not sure what the dealer was doing there.....

 

I made a mistake in the error code. The error code was P2764.

 

Torq Conv Clutch Press Ctrl Solenoid Ctrl Circ Low

That's an electrical problem, not a mechanical problem. Voltage is low on the control circuit for the TCC solenoid.