DTC P0449: EVAP Vent Valve Performance: Description

An ignition voltage is supplied directly to the Evaporative (EVAP) emission canister vent valve. The Powertrain Control Module (PCM) controls the EVAP vent valve by grounding the control circuit via an internal switch called a driver. The primary function of the driver is to supply the ground for the controlled component. The PCM monitors the status of the driver. If the PCM detects an incorrect voltage for the commanded state of the driver, DTC P0449 sets.