Possible causes

– Purge Control Valve harness is open or shorted
– Purge Control Valve electrical circuit poor connection
– Faulty canister vent control valve

When is the code detected?

The Engine Control Module (ECM) has determined that a malfunction exists in the electrical circuit for the vent valve/solenoid in the evaporative emission control system.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P0449 Description

The Evaporative Emission System (EVAP) canister vent control valve is located on the EVAP canister and is used to seal the canister vent. This solenoid (the EVAP canister vent control valve) responds to signals from the Engine Control Module (ECM). When the ECM sends an ON signal, the coil in the solenoid valve is energized.
A plunger will then move to seal the canister vent. The ability to seal the vent is necessary for the on board diagnosis of other evaporative emission control system components.
This solenoid valve is used only for diagnosis, and usually remains opened. When the vent is closed, under normal purge conditions, the evaporative emission control system is depressurized and allows EVAP Control System (Small Leak) diagnosis.

P0449 Information for specific makes

P0449 BUICK
P0449 GMC
P0449 CADILLAC
P0449 CHEVROLET
P0449 HYUNDAI
P0449 ISUZU
P0449 KIA
P0449 VOLKSWAGEN
P0449 AUDI
P0449 PONTIAC
P0449 SATURN
P0449 2006 GMC SIERRA