This engine P1765 Code problem may stat for various causes and it is important to know the real meaning of the car engine code. The engine P1765 code on cars with electronically maintained automatic transmissions, the 3-4 shift solenoid is accountable for actuating the hydraulic circuits to activate clutches or bands that change gears inside the automatic transmission. Do not solve the car engine by immature person. You may face terrible problem in the car engine due to the wrong meaning of the code and taking help from wrong person. You must take the car to a repair center to check and solve the car engine problem.