Technical Description of OBD-II Trouble Code
The circuit controlling the vent valve or solenoid for the evaporative emission systems vapor is open, resulting in the code P0447. This code is considered generic and applies to all vehicle makes and models (1996-newer), although the repair steps may vary depending on the specific model.
What does this mean?
The Powertrain Control Module (PCM) has detected an open circuit in the vent valve or solenoid that controls the vapor in the evaporative emission systems. As fuel sits in the tank, it releases fuel vapor. While driving, the vent opens to allow the vapors to circulate into the engine intake manifold, a charcoal canister, or into the atmosphere, depending on the vehicle. This vent valve is part of the simple yet complicated evaporative emissions system.
Symptoms
Symptoms of the P0447 DTC include the illumination of the Malfunction Indicator Lamp (MIL), but you are unlikely to notice any other symptoms.
Causes
Potential causes of this code may include:
Possible Solutions
Some steps to diagnose and repair this trouble code include the following:
Check the fuses, as there may be a fuse that powers the vent solenoid.
Inspect the wiring harness for any rubbing or chafing. Check both wires to see if they are open to each other, to ground, or to power.
Visually examine the vent valve for any cracks or damage.
Trace the wires to and from the PCM and check for continuity using a digital volt ohm meter (DVOM).
If you have access to an advanced level scan tool, actuate the valve while reading power and ground at the connector or by using a bulb wired to both terminals. The bulb will light up if power and ground are okay.
Using a DVOM, check the resistance of the vent. In most cases, the resistance reading should be low. Refer to the manufacturer’s specifications or compare it to a new one. If the value is too high or too low, it indicates a faulty coil inside the valve and replacement is necessary. This code appears to be common in Dodge, Chrysler, and Jeep products, where the vent valve was found to be faulty. For GM products, specifically pickups, GM has released a new updated valve assembly.
Finally, remove the valve and check if the pintle inside is sticking due to fuel residue. Clean it and retest.
Other EVAP DTCs: P0440 – P0441 – P0442 – P0443 – P0444 – P0445 – P0446 – P0448 – P0449 – P0452 – P0453 – P0455 – P0456
