P0449: Evaporative Emission System Vent Valve/Solenoid Circuit
The engine computer has found an electrical fault in the EVAP vent valve solenoid or its circuit.
What P0449 means
P0449 is closely related to P0446. RepairPal explains that it indicates the EVAP vent valve solenoid is malfunctioning, which can be caused by too little or too much electrical resistance in the circuit. Some makers use P0449 for the solenoid circuit and P0446 for vent performance, so it is normal to see either or both. The vent valve has to open for normal purging and refueling and close for the leak test. If the solenoid coil fails or the wiring is open, the valve may stay in one position, which can cause filling problems or false leak codes. Since the valve and connector are under the car near the tank, water, mud and road salt take a toll. KBB notes that vapor in the cabin can be dangerous, so take a strong fuel smell seriously. Shops check the fuse, measure solenoid resistance and use a scan tool to command the valve closed and open while watching tank pressure.
Common symptoms
- Check engine light on
- Trouble filling the gas tank
- Fuel odor near the car
- Usually no driveability change
- Other EVAP codes may appear
Most common causes
- Failed vent valve solenoid
- Open or shorted wiring to the vent valve
- Corroded connector
- Blown fuse in the EVAP circuit
- Vent valve clogged by debris
What to check yourself first
Check the EVAP fuse. Locate the vent valve near the tank and inspect the connector and wires for corrosion or damage. Clean out any mud or debris from the vent filter or hose.
Typical fixes and what they cost
| Fix | Typical cost | Note |
|---|---|---|
| Replace EVAP canister (includes vent valve on many cars) | $558-$643 | Many vent valves are part of, or mounted on, the canister assembly. |
| Electrical diagnosis to find a wiring or connector fault | $122-$179 | For wiring, fuse or connector problems. |
| Check engine light diagnosis at a shop | $125-$183 | Separates a bad solenoid from a wiring fault. |
Typical US price ranges for parts and labor, not quotes. Your shop should confirm the cause with a diagnostic before replacing parts.
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Related codes
- P0446 Evaporative Emission System Vent Control Circuit
- P0455 Evaporative Emission System Leak Detected (large leak)
- P0442 Evaporative Emission System Leak Detected (small leak)
- P0440 Evaporative Emission System
- P0443 Evaporative Emission System Purge Control Valve Circuit