OBD code P0446 indicates an issue with the evaporative emission control system vent control circuit. This code is triggered when the car’s computer detects a malfunction in the circuit responsible for controlling the vent valve that manages the flow of fuel vapors from the fuel tank to the engine.
1. What are the possible symptoms ?
1. Check Engine Light illuminated on the dashboard
2. Decreased fuel economy
3. Difficulty starting the vehicle
4. Strong gasoline smell from the vehicle
5. Vacuum leak in the evaporative emission control system
2. What are the most probable causes ?
1. Faulty EVAP vent valve
2. Clogged EVAP canister
3. Open or shorted EVAP vent valve circuit
4. Damaged wiring or connectors in the EVAP system
5. Loose or missing fuel cap
6. Cracked or disconnected EVAP hoses
7. Faulty purge valve
8. Malfunctioning engine control module (ECM)
3. Is it safe to drive with this fault not fixed?
Continued driving with the OBD fault code P0446-Evaporative Emission System Vent Control Circuit may not pose an immediate safety risk, but it can lead to increased emissions and reduced fuel efficiency.
4. What is the severity level of this fault code ?
P0446 is a moderately severe OBD code that can affect the vehicle’s emissions system. It’s a relatively common fault in many vehicles and may require attention to prevent potential emissions issues.
5. How much will cost to repair this fault ?
The cost of repairing the OBD fault code P0446 can range from $150 to $300, depending on the mechanic’s labor rates and the cost of replacement parts. It’s best to get quotes from different auto repair shops to find the most competitive price.
6. Troubleshooting – List of most reported fixes :
1. Check and replace the faulty Evaporative Emission (EVAP) vent control solenoid.
2. Inspect the wiring and connectors in the vent control circuit for any damage or corrosion, and repair or replace as necessary.
3. Verify that the canister vent valve is functioning properly and replace it if found to be faulty.
7. What are the most affected components by this fault code ?
1. EVAP canister vent valve
2. EVAP system hoses
3. Charcoal canister
4. EVAP canister purge valve
5. Wiring and connectors
6. PCM (Powertrain Control Module)
8. Several risks you may face if this issue is not fixed :
1. Increased air pollution due to the release of harmful emissions into the atmosphere.
2. Reduced fuel efficiency and increased fuel consumption.
3. Potential damage to the catalytic converter and other emission control components.
4. Possibility of the vehicle failing emissions tests and inspections.
5. Risk of the vehicle not running at its optimum performance level.
9. Most frequent questions people ask on AutoForums about this fault :
1. Can a faulty gas cap cause OBD fault code P0446-Evaporative Emission System Vent Control Circuit?
Yes, a faulty gas cap can cause the P0446 code. If the gas cap is not sealing properly, it can lead to a leak in the evaporative emission system, triggering the P0446 code.
2. What are the common symptoms of OBD fault code P0446-Evaporative Emission System Vent Control Circuit?
Common symptoms include the Check Engine light coming on, a noticeable fuel odor, and potentially a slight decrease in fuel economy.
3. How can I troubleshoot OBD fault code P0446-Evaporative Emission System Vent Control Circuit?
Start by checking the gas cap for proper sealing, inspecting the EVAP system hoses for leaks, and testing the EVAP vent valve for proper operation.
4. Can the P0446 code cause any damage to the vehicle if left unresolved?
While the P0446 code itself may not cause immediate damage, it should be addressed promptly as it can lead to increased emissions and may affect the vehicle’s overall performance.
5. What is the typical cost to repair OBD fault code P0446-Evaporative Emission System Vent Control Circuit?
The cost varies depending on the cause of the issue, but it may involve replacing the gas cap, repairing or replacing EVAP system components, or addressing wiring/connectivity issues. It’s best to consult a professional for an accurate assessment.
10. Diagnostic cautions and safety measures :
1. Ensure the vehicle’s fuel cap is tightened securely before diagnosing the fault code P0446.
2. Check for any visible damage or leaks in the evaporative emission system components, such as hoses, canister, and vent valve.
3. Inspect the electrical wiring and connectors related to the evaporative emission system for any signs of damage or corrosion.
4. Verify that the EVAP system’s purge and vent solenoids are functioning properly and not stuck open or closed.
5. Use diagnostic tools to perform a thorough inspection of the EVAP system, including smoke testing and voltage checks, to identify the root cause of the P0446 fault code.
This article was crafted using OBDQuest, the app that demystifies OBDII codes with clear explanations, fixes, and troubleshooting tips. Download OBDQuest from Google Play or the App Store. Subscription is at lowest price right now. Get started today and simplify your car diagnostics.
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