The engine P1521 Code is an important thing and this is important to know the real meaning of the code for solving the car engine. The meaning of the code is necessary to know. The powertrain is the problem and it is easy to solve. This problem can be fixed without changing any part of the car engine. You do not need to expense huge money for adding part. You should not worry about it. The problem should be fixed by automobile engineer and you can fix it in the automobile engineer center. Every parts of the car engine code are meaningful.