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P0446 Chevrolet Code - Evaporative Emission Vent System Performance

Quick Answer

This Diagnostic Trouble Code (DTC) tests the Evaporative Emission (EVAP) system for a restricted or blocked EVAP vent path that would cause excess amounts of vacuum to be developed in the EVAP system. Common causes include Plugged vapor canister, Pinched or blocked EVAP hose, Faulty Evaporative Emission Vent Solenoid Valve. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

What it means
P0446 Chevrolet indicates Evaporative Emission Vent System Performance.
Common causes
Common causes include Plugged vapor canister, Pinched or blocked EVAP hose, Faulty Evaporative Emission Vent Solenoid Valve.
Severity
Low - monitor the vehicle and repair when practical.
Can I drive?
The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.
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Code Popularity 190,982
How popular is this code, among other codes? High
What is this?
Table of contents Created and updated by William Orellana on Jul 21, 2022
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Code P0446 Chevrolet Description

This Diagnostic Trouble Code (DTC) tests the Evaporative Emission (EVAP) system for a restricted or blocked EVAP vent path that would cause excess amounts of vacuum to be developed in the EVAP system. The Engine Control Module (ECM) commands the EVAP purge solenoid valve Open and the EVAP vent solenoid valve Closed. This allows vacuum to be applied to the EVAP system. Once a calibrated vacuum level has been reached, the ECM commands the EVAP purge solenoid valve Closed and the EVAP vent solenoid valve Open. The ECM monitors the Fuel Tank Pressure (FTP) sensor for a decrease in vacuum. If the vacuum does not decrease to near 0 in H2O in a calibrated time, this DTC sets.
OBDII Code P0446 Chevrolet - Evaporative Emission Vent System Performance - AutoCodes.com
P0446 Chevrolet Code - Evaporative Emission Vent System Performance
What does this mean?

What are the Possible Causes of the DTC P0446 Chevrolet?

  • Plugged vapor canister
  • Pinched or blocked EVAP hose
  • Faulty Evaporative Emission Vent Solenoid Valve
  • Evaporative Emission Vent Solenoid Valve harness is open or shorted
  • Evaporative Emission Vent Solenoid Valve circuit poor electrical connection
  • Faulty Fuel Tank Pressure (FTP) sensor

How to Fix the DTC P0446 Chevrolet?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

Dirt and dust intrusion into the EVAP canister vent hose assembly, resulting in restricted air flow, may cause this condition.

There is a bulletin for the following models:
1999-2007 Chevrolet Silverado (Classic) Models
2007-2008 Chevrolet Silverado Models
Chevrolet Factory Service Bulletin OBDII Code P0446





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What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0446 Chevrolet code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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Information for Specific Chevrolet Models

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0446 Chevrolet Code

1. What are the common symptoms of OBDII code P0446 on a Chevrolet related to the Evaporative Emission Vent System?

- Common symptoms include the illumination of the check engine light, the smell of fuel vapors, and potential issues with the vehicle's fuel economy.

2. What can cause OBDII code P0446 to trigger in a Chevrolet vehicle?

- The code P0446 is typically triggered by a fault in the Evaporative Emission Vent System, often caused by a malfunctioning vent valve or a clogged vent line.

3. How can I diagnose the OBDII code P0446 on my Chevrolet related to the Evaporative Emission Vent System?

- Diagnosing the code involves performing a thorough inspection of the vent valve, vent line, and the overall integrity of the Evaporative Emission Vent System components.

4. What are some potential repair tips for addressing OBDII code P0446 on a Chevrolet?

- Repair tips may include cleaning or replacing the vent valve, checking and clearing any obstructions in the vent line, and ensuring proper connections within the Evaporative Emission Vent System.

5. Can driving with OBDII code P0446 on a Chevrolet cause further damage to the vehicle?

- While driving with the code may not immediately cause significant harm to the vehicle, it is recommended to address the issue promptly to prevent potential long-term damage to the Evaporative Emission Vent System.

6. How much does it typically cost to repair OBDII code P0446 on a Chevrolet at a professional automotive service center?

- The cost of repairing the code P0446 can vary depending on the exact cause of the issue, but it may range from $100 to $300 for parts and labor at a professional service center.

7. Are there any DIY steps I can take to try and resolve OBDII code P0446 on my Chevrolet before seeking professional help?

- DIY steps may include visually inspecting the vent valve and vent line for any visible damage or obstructions, as well as checking for loose connections in the Evaporative Emission Vent System.

8. Is it safe to continue driving my Chevrolet with the check engine light on due to OBDII code P0446?

- While it may be safe to drive the vehicle in the short term, it is recommended to address the code promptly to prevent potential issues with emissions and overall vehicle performance.

9. Can extreme weather conditions affect the likelihood of triggering OBDII code P0446 on a Chevrolet?

- Extreme weather conditions, such as temperature fluctuations, can potentially impact the Evaporative Emission Vent System and contribute to the triggering of code P0446 on a Chevrolet.

10. How frequently should the Evaporative Emission Vent System be inspected and maintained to help prevent OBDII code P0446 from occurring in a Chevrolet?

- It is recommended to include a routine inspection of the Evaporative Emission Vent System as part of regular vehicle maintenance to help prevent issues that may lead to code P0446 in a Chevrolet.

Discuss the causes and fixes for P0446 Chevrolet OBDII Code

Submit a New Comment

  • my 1998 Olds. Bravada has a p0446 code, where is the canister and how do I fix it.

    Reply to Comment

  • i have a code p0446 i replace the gas cap and the pressure sensor and evap vent valve solenoid and the one under the hood still check engine light on also it hard to fill my tank the gas keep shutting off and no no pressure when i take the gas cap off

    Reply to Comment

  • Let me check if there any more information. What model and year is your vehicle?

    Reply to Comment
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