P0456 - EVAP CONTROL SYSTEM LEAK DETECTED VERY SMALL LEAK

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.

• Check Engine light on the board.
• You can smell a fuel odor due to the release of fuel vapors.

The frequent problems for the establishment of P0456 code can be:

• A gas cap that is installed incorrectly or may be defective.
• There may be a leak in one of the hoses of the Evaporative Emissions Control System (EVAP), or even one of the fuel tank hoses.
• Perhaps the purge valve or vent valve leaks.
• The EVAP system reservoir may leak.

To solve the diagnostic code P0456 you can do the following:

• Check that the fuel cap is in good condition, change if necessary.
• Visually inspect the vacuum and fuel vapor hoses for cracks or any cracks. Repair or change as necessary.
• Using a scan tool, activates the ventilation solenoid. Watch the FTP sensor (Fuel Tank Pressure). If the system is sealing correctly, the Fuel Tank Pressure Sensor will display a constant number. Otherwise, the sensor will also indicate it. If the system releases slowly, use a smoke machine and see if there is smoke coming from any component of the EVAP system. Any place where there is smoke coming out, is indicative that the component is defective.