DTC P0442 & DTC P0456: Notes
Code Definition
- DTC P0442: EVAP Emission Control System Small Leak Detected
- DTC P0456: EVAP Emission Control System Small Leak Detected (0.5 mm)
NOTE:
To judge if there is a leak in the fuel system, PCM measures the change of pressure in the fuel tank. PCM turns ON the EVAP emission ventilation solenoid to shut OFF the EVAP canister outlet port. Then the EVAP system emission purge solenoid is driven to set the fuel system into a vacuum. When a vacuum of 0.29 psi (2 kPa) is developed within the fuel system, the EVAP system emission purge solenoid is turned OFF. Vacuum is maintained at 0.29 psi (2 kPa). The PCM monitors if there is a leak in the fuel system by measuring the change of vacuum inside the fuel tank. Test is stopped when fuel vapor pressure is judged as too high.