What P0765 usually means
P0765 means the transmission controller has detected a problem in the D-side shift-solenoid command path. On real vehicles this code usually shows up when the transmission loses confidence in one hydraulic command channel that helps complete gear changes cleanly. Owners often describe the result as a sudden no-upshift event, one bad shift that turns into broader harshness, or a fallback strategy that appears after the module sees the D path misbehave.