You need to know the meaning of the car engine when you decide to fix the car engine. The car engine code can be found if you test the car engine by machine. The meaning of the code should be taken form the car manufacturer. The car engine code has many meanings and this error engine P2638 Code has also some meanings but you must allow the right meaning what is found from the car manufacturer. The car engine code is helpful by the right meaning of the code. The car engine code has general meaning what can be used for solving the car engine.