P0449 - EVAPORATING EMISSION CONTROL SYSTEM MALFUNCTIONING VENT VALVE / SOLENOID CIRCUIT
POST UPDATED IN June, 2023
Description of DTC code P0449 Generic
The fault code P0449 OBD2 is a generic code and means that the PCM (Powertrain Control Module) has detected a fault in the circuit that controls the ventilation for the vapors in the steam emission system.
When the fuel begins to settle in the tank, the fuel vapor is expelled. As the vehicle is running, the vent opens allowing the vapors to circulate either to the intake manifold, the active carbon filter, or to the atmosphere, depending on the model of your vehicle.
This ventilation valve, although it is simple, it is part of the complex EVAP system (Evaporative Emission Control System).
Factors that may lead to the establishment of DTC code P0449 are
There may be a short in the wiring system.
The electrical connection in the circuit is poor or incorrect.
The ventilation valve of the carbon filter may be defective.
Possible solutions of the DTC code P0449 Generic
The steps to correct the diagnostic code P0449 OBD II faults are
Check the fuses. There may be a defective vent solenoid drive fuse. Change it if necessary.
Check the cables, make sure they're in good condition. If you find any wires that are worn, broken or rubbing against other components, repair them, or replace them.
Visually check that the vent valve is working properly. Besides, make sure it does not have cracks or other damage. You must change it if it has defects.
If you have a digital multimeter, check that there is continuity in the cables from the PCM to the EVAP system (The evaporative emission control system). Repair any defects.
With a scanning tool, operate the valve and observe the power reading and the ground connection. To perform this check, you can use a test lamp, connect it to the 2 terminals and if it lights up it indicates that the power and ground connection is correct.
With a multimeter, check the vent resistance. The result of this reading is that it should be low. Compare the results with the manufacturer's specifications. If it is high in excess, it indicates that the coil inside the valve is defective. You should replace it.