The EVAP vent valve allows fresh outside air to enter the canister during purge modes. The vent solenoid is closed only while the EVAP diagnostic runs. The voltage on the solenoid control circuit is monitored continuously. If the ECM does not detect any voltage on the control circuit, this DTC will set.

DTC P0449 will set when:

P0449 is a (type B) DTC.

To locate an intermittent problem, use the scan tool to monitor the actual EVAP purge solenoid with engine running.

Wiggling wires while monitoring the EVAP purge solenoid may locate the area where a short to ground exists.