The engine P1756 Code is set many car engines and it lets us know about the car engine problem. The valves of each cylinder of the car engine are remain closed by using a pair of arms what change the conventional engine’s roller-type rocker arm. The engine P1756 code is one of these arms what follows the cam profile while the 2nd arm joins to the valves. During the normal engine operation the 2 arms are joined by a locking pin. Use the real meaning of the code to know the exact problem of the car engine and fix the car engine issue as soon as possible.