Re: transmission solenoid pack problems
The P0750 you had already before (L/R solenoid/circuit), but the P0765 is new (UD solenoid/circuit.)
The UD solenoid is used for 1st, 2nd, 2nd prime and 3rd gear.
I would really suspect some wiring problem or the TCM itself. Remove the connector from the TCM and from the solenoid block and measure each wire for short to ground ( or at least the ones used for the L/R and UD solenoids). The resistance should be infinite or at least several mega Ohms. If all ok, measure the wires also for continuity (so 0 Ohm or lower then a few Ohms max.)