P0449 - OBD II Trouble Code
Vent Valve/Solenoid Circuit Malfunction
Our emissions expert has put together the following information about the P0449 fault code. We have also included diagnostic procedures you can take to your repair shop if the mechanic is having difficulty analyzing the code.
OBD II Fault Code
Fault Code Definition
What does this mean?
- Evaporative System Vent Control Circuit Malfunction
The evaporative control (EVAP) system captures any raw fuel evaporating from the fuel storage system (e.g. the fuel tank, filler neck, and fuel cap). Under precise operating conditions-dictated by engine temperature, speed, and load-the EVAP system stores and purges these captured fuel vapors back into the combustion process. The carbon canister, which stores the raw fuel vapors, utilizes a vent valve that allows fresh air to enter the EVAP system. This displaces the fuel vapor as it's purged into the combustion process.
indicates that the evaporative control (EVAP) system vent valve solenoid is malfunctioning. This can be caused by either too little or too much electrical resistance or a mechanical problem with the vent valve itself.
Common Problems That Trigger the P0449 Code
- Check Engine Light will illuminate
- In most cases, there are no adverse conditions noticed by the driver
- In some cases, there may be a noticeable fuel odor caused by the release of fuel vapors
- Missing fuel cap
- Defective Evaporative Vent Valve
- Defective or damaged fuel cap
- Distorted, damaged or cracked Fuel Tank Filler Neck
- Torn or punctured Evaporative system hose(s)
- Defective Fuel Tank Sending Unit gasket or seal
- Split or damaged Carbon Canister
- Defective or damaged fuel tank
Polluting Gases Expelled
- Fuel cap
- Evaporative Purge Valve
- Evaporative Vent Valve
P0449 OBD II Trouble Code
- HCs (Hydrocarbons): Unburned droplets of raw fuel that smell, affect breathing, and contribute to smog