The engine P0904 Code exists in the car engine and meaning of the code helps for solving the car engine problem. Do not use wrong meaning of the code for solving the car engine. However, the letter P lets you know about the problem of the powertrain. This problem of the powertrain is easy to fix and it is not necessary to change any part of the car engine. The engine code should be fixed properly. Do not allow wrong meaning for solving the car engine. You will learn more information from the automobile dictionary meaning. When the car engine is fixed, you need to take it for a test drive.