Process of the fixing the car engine is necessary to know and the engine U1794 Code is related with the car engine problem and this code appears on the car engine code reader screen. Follow the method of fixing the car engine is given below. The multi-displacement method turned off differing pairs of cylinders, letting the engine to have 3 different outlines and displacements. The engine U1794 code had an elaborate diagnostics process, with showing engine problem codes on the air conditioning display. However, the system was upsetting, misjudged by customers, and a rash of erratic letdowns led to the technology being fast discharged.