The diagnostic code P0496 refers to the EVAP system (Evaporative Emission Control System). The PCM (Powertrain Control Module) closes the EVAP system (The evaporative emission control system) through the purge valve. At the right time, the PCM commands the purge valve to open, allowing engine vacuum to be applied to the EVAP vessel. When this valve is open, fresh air is drawn through the vessel, resulting in the extraction of fuel vapors to the carbon.
Likewise, the PCM (Powertrain Control Module) monitors the FTP sensor (Fuel Tank Pressure Sensor) to determine if the EVAP system is taking on vacuum. If the vacuum taken from the EVAP exceeds the default value in a predetermined time, the DTC code P0496 OBD2 is set.