If you do not know about the car engine, do not try to fix the car engine. The engine P0742 Code is a supporting thing what comes by the testing the car engine. The engine code lest you know detail of the car engine and helps to solve problem. You must accept the meaning of the code from the car manufacturer. If you use different meanings of the code from different car manufacturers what has no relation with your car, then you should avoid that meaning. It is better if you give the automobile engineer to fix the car engine.