The P0446 fault code indicates that the evaporative emission control system (EVAP) vent control circuit may be malfunctioning. When the vehicle engine computer (PCM) detects a problem with the EVAP vent control, it depicts an OBD2 error code.
OBD2 Code P0446; What is it and what does it indicate?
The P0446 error code does not indicate a direct defect or faulty component, but an electrical fault in either the vent valve or its control circuit.
What is EVAP Vent Control Circuit?
The engine control module (ECM) operates the vent control valve, which permits air to flow into the charcoal canister to evacuate gas vapors into the engine air intake, where they may be burnt. It helps in preventing harmful fumes or emissions to release into the atmosphere.
The error number P0446 indicates that there is an abnormal voltage drop in the EVAP system’s vent valve circuit. If there is either too much or too little electrical resistance, it can cause a decline in the voltage. If this were to happen, it would indicate that the EVAP system’s vent valve is going to fail, which requires immediate action.
OBD2 P0446 Code Error; Causes
What causes the Vent Control Circuit Malfunction in the Evaporative Emission Control System?
- A malfunctioning, missing, or cracked gas cap might be present.
- Hose failures in the EVAP system
- There might be a gasoline tank leak.
- The charcoal canister may be cracked or faulty.
- The vent valve has a flaw.
- On the vent valve control circuit, there should be no open, short, or excessive resistance.
- Vent valve blockage
- The powertrain control module’s defaults
OBD2 Error Code P0446; Symptoms
It is critical to understand the signs of a problem since only then will you be able to fix it. As a result, we’ve compiled a list of some of the most common OBD Code P0446 symptoms you can have a look at.
- The fault indication bulb is illuminated.
- The fuel efficiency may begin to deteriorate.
- Fuel stink is a problem that may be produced by fuel vapors that have been emitted.
- The automobile engine may idle, stall, or hesitate.
OBD2 P0446 Code Error; Diagnosis
To diagnose this problem code, you should do the following steps:
- Check for any codes using the scan tool, and make a note of any freeze frame data.
- Remove any codes from the computer in the car.
- Confirm the allegation by doing a vehicle road test.
- Look for damage to the gas cap, fuel tank, EVAP lines, and charcoal canister during a visual check of all EVAP system components.
- With a gas cap tester, thoroughly inspect the gas cap for any damage and ensure a good fitting.
- To monitor tank pressure data and ensure that it is reading correctly, a scan instrument should be utilized.
- Self-test the EVAP system using a scan tool to ensure that all valves and solenoids are working properly.
- If none of the preceding tests yielded compelling results, do a smoke test on the EVAP system.
Mistakes to Avoid When Diagnosing The P0446 Code
When proper attention is not given to completing or following all the necessary steps, the chances of appearing and reappearing the P0443 code are more. Make sure you are looking into the manual or the documentation to take necessary actions using the proper tools.
How To Fix P0446
If you want to fix the P0446 Evaporative Emission Control System Vent Control Circuit Malfunction at the earliest without spending much, you are at the right place. Here are some fixes you can perform as per the diagnosis.
- Replace the defective vent valve with a new one.
- In a control circuit, you can always fix an open, short, or resistance fault.
- The PCM that has been damaged should be repaired.
- Repair the control circuit that is shorted, open, or resistive.
- Restore the PCM in your car.
If there are any problems with the EVAP system vent valve, it should be changed immediately to prevent major issues that can cause driving issues.
Vehicles that usually face P0446 issues?
Is it okay to drive while having a P0446 code on your computer?
As a consequence of the P0446 error code, you are not in any immediate danger. However, if you come across this code, you take crucial measures to resolve the issues as soon as possible. You may notice a decrease in fuel efficiency in addition to the check engine light. Even though this code is unlikely to result in a life-threatening situation, anything that causes the check engine light to activate should be investigated further.
Where is an EVAP vent valve located in the vehicle?
The EVAP vent valve is often located below the car, near or at the charcoal canister, which is located near the fuel tank. Therefore, the most common reason for the P0443 error code is rust which results in equipment failure. The most often seen problem is when the vent valve becomes stuck open or malfunctions.
How much does it cost to repair a vent valve in a house?
As a whole, you should budget between $50 to $120, if you are thinking of repairing your vent valve at home. However, the most cost is for equipment or spare parts which can cost you between $80 to $200. On the other hand, the labor cost is $50 and $80.
What happens if the purge valve is stuck shut and cannot be opened?
If a canister purge valve is stuck in the closed position, the system will not be able to burn the evaporated gasoline in the engine. Consequently, the purge flow code will be set to a low value, which may cause the charcoal canister in the evaporative emissions system to fail prematurely.