The evaporative emission (EVAP) system is used to store fuel vapors as to reduce the amount of unburned fuel from escaping into the atmosphere. The EVAP vent solenoid allows fresh outside air to enter the canister during purge modes. The EVAP vent solenoid is closed only while the EVAP diagnostic runs The ECM controls an internal driver that supplies a ground to the solenoid. When the driver is commanded Off (circuit not grounded), the voltage level at the ECM should be high (ignition voltage). When the driver is commanded On (circuit grounded), the voltage level at the ECM should be low. The ECM driver feedback circuit uses a pull-up voltage (2.6-4.6 volts), which allows the ECM to individually differentiate between an open, short to ground or short to voltage. DTC P0447 will set if the ECM detects an open in the EVAP vent solenoid control feedback voltage when the driver is commanded Off.

P0447 will set if the ECM detects an EVAP vent solenoid control feedback voltage is between 2.6 - 4.6 volts when the driver is commanded Off when:

DTC P0447 diagnostic runs continuously with ignition On and the above conditions have been met.

P0447 is a (type B) DTC.

Inspect harness for any backed out terminals, improper terminal mating, or corrosion that may cause an open circuit condition.

EVAP vent solenoid resistance: 18-27 ohms.