The engine P0674 Code is found in the car engine and meanings of the code depend on many things. You need to get the right meaning of the code for solving the engine and it helps most but if you do not know the right meaning of the code, you can use automobile dictionary meaning and that is p for Powertrain Code Problem is related engine, transmission and emissions systems. 0 for SAE – Generic. 6 for Vehicle Speed Control And Idle Control System. 7 for Vehicle Speed Output Circuit and 4 for Cruise Vehicle Speed or Set Speed Difference Too High.