DTC P0446: Evaporative Emission Vent System Performance: Description

This DTC tests Evaporative Emission (EVAP) system for a restricted or blocked EVAP vent path. Powertrain Control Module (PCM) commands EVAP purge solenoid and vent solenoid on. This allows a vacuum to be applied to EVAP system. Once a calibrated vacuum level has been reached, PCM commands EVAP purge solenoid and vent solenoid off. PCM monitors Fuel Tank Pressure (FTP) sensor for a decrease in vacuum.