The purpose of the EVAP system (Evaporative Emissions Control System) is to prevent the vapors of the fuel tank from being expelled into the atmosphere, being the engine responsible for eliminating them, as it burns them. The Evaporative Emissions Control System (EVAP) on a regular basis is monitored by the Power Train Control Module (PCM). Therefore, it performs periodic pressure tests to monitor the system for leaks.
The PCM (Powertrain Control Module) controls the pressure of the evaporative emission control system (EVAP), taking into account the FTP sensor (Fuel Tank Pressure), in case this sensor indicates the presence of a leak in the system EVAP, the fault code P0456 OBD2 is established.