P0446 GMC Code - Evaporative Emission Vent System Performance
Quick Answer
The P0446 code for GMC vehicles indicates a problem with the evaporative emission vent system's performance. Common causes include Faulty vent valve, Clogged or damaged charcoal canister, Damaged hoses or tubing in the vent system. 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 GMC indicates Evaporative Emission Vent System Performance.
- Common causes
- Common causes include Faulty vent valve, Clogged or damaged charcoal canister, Damaged hoses or tubing in the vent system.
- 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.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
Code P0446 GMC Description
The P0446 code for GMC vehicles indicates a problem with the evaporative emission vent system's performance. This system is responsible for capturing and storing fuel vapors before they can escape into the atmosphere. The vent system allows fresh air to enter the charcoal canister to displace the fuel vapors, which are then sent to the engine to be burned off. When this system malfunctions, it can lead to increased emissions and potential performance issues.
Common Causes of P0446 GMC
- Faulty vent valve
- Clogged or damaged charcoal canister
- Damaged hoses or tubing in the vent system
- Electrical issues with the vent valve circuit
- Loose or damaged gas cap
Symptoms of P0446 GMC
- Check engine light illuminated
- Strong fuel odor coming from the vehicle
- Decreased fuel efficiency
- Rough idling or stalling
- Difficulty starting the vehicle
How to Fix P0446 GMC
- Diagnose the issue using a scan tool to pinpoint the exact cause of the problem
- Inspect the vent valve, charcoal canister, hoses, and tubing for any damage or clogs
- Replace any faulty components such as the vent valve or charcoal canister
- Clear the diagnostic trouble codes and perform a test drive to ensure the issue has been resolved
- If the issue persists, further diagnostic testing may be needed to identify any other underlying problems
Cost to Fix P0446 GMC
The typical repair costs for a P0446 code can vary depending on the specific cause of the issue and the labor rates in your area. On average, you can expect to pay between $100 and $500 for parts and labor. Keep in mind that additional diagnostic time or replacement of multiple components may increase the overall cost. It's recommended to consult with a qualified mechanic to get an accurate estimate based on your vehicle's make and model.
Tech Notes for P0446 GMC
There is a bulletin for the following models:
1999-2007 GMC Sierra (Classic) Models
2007-2008 GMC Sierra Models
GMC Factory Service Bulletin OBDII Code P0446
User Submitted Video
Need more information about the P0446 GMC code?
Need more information on how to fix the P0446 GMC code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P0446 GMC code diagnosed by a professional: Find a repair shop in your area
Information for Specific GMC Models
- P0446 2014 GMC Sierra — Evaporative Emission Vent System Performance
- P0446 2015 GMC Sierra — Evaporative Emission Vent System Performance
- P0446 2016 GMC Sierra — Evaporative Emission Vent System Performance
- P0446 2017 GMC Sierra — Evaporative Emission Vent System Performance
- P0446 2018 GMC Sierra — Evaporative Emission Vent System Performance
Frequently Asked Questions about P0446 GMC Code
1. What are common symptoms of OBDII code P0446 in a GMC vehicle?
- Common symptoms include the illumination of the check engine light, a noticeable fuel odor, and potential difficulties during refueling.
2. What does the OBDII code P0446 on a GMC indicate?
- OBDII code P0446 indicates a problem with the Evaporative Emission Vent System Performance in the vehicle.
3. What are some possible causes of OBDII code P0446 in a GMC?
- Potential causes may include a faulty vent valve, a clogged vent filter, damaged charcoal canister, or issues with the electrical circuit related to the evaporative emission system.
4. How can I diagnose the OBDII code P0446 in my GMC?
- Diagnosis typically involves inspecting the vent valve, checking for blockages in the vent filter, examining the charcoal canister, and testing the electrical connections in the evaporative emission system.
5. Can I continue driving my GMC with OBDII code P0446?
- While the vehicle may still be operable with this code, it is recommended to address the issue promptly to prevent potential damage to the emissions system and ensure optimal performance.
6. How can I repair OBDII code P0446 in my GMC?
- Repairing this code often involves replacing the faulty vent valve, cleaning or replacing the vent filter, repairing or replacing the charcoal canister, and addressing any electrical issues in the system.
7. Is it possible to reset OBDII code P0446 in a GMC without fixing the underlying issue?
- While clearing the code may temporarily turn off the check engine light, it is crucial to address the root cause of the problem to prevent future issues and ensure proper vehicle operation.
8. Are there any DIY tips for resolving OBDII code P0446 in a GMC?
- DIY tips may include checking for loose or damaged hoses, inspecting the vent valve for proper operation, and ensuring all connections in the evaporative emission system are secure.
9. How long does it typically take to repair OBDII code P0446 in a GMC?
- The repair time can vary based on the specific cause of the issue, but it may take anywhere from 1 to 3 hours to diagnose and fix the problem related to the Evaporative Emission Vent System Performance.
10. Should I seek professional help to address OBDII code P0446 in my GMC?
- It is advisable to consult a qualified mechanic or automotive technician to accurately diagnose and repair OBDII code P0446 in your GMC to ensure the problem is resolved correctly and efficiently.
Discuss the causes and fixes for P0446 GMC OBDII Code
-
What's the most likely causes for a 0446 code, how fast does it have to be fixed(will it cause any damage to engine?), and where is the parts to replace located on a 2010 GMC Terrain 2.4L 4cyl?
-
There are some tests that needs to be done to determine exactly what the problem is. Problem with the EVAP system should not affect the engine performance or damage another components, but your vehicle will fail the smog test.
-
engine will not stay running,got p0446 code on a scan should i change out the vent valve canister?
-
What model and year is your vehicle? Yes, the valve is the most likely cause of the problem.
-
Hello
I have a 2008 GMC 2500 HD with 6000 yes only 6000 miles I bought it new .. never been driven in snow or wet roads . The underside is spotless.. I keep getting the PO446 error code reset oncew returned.. Any advise on why and what could cause this .. like new truck -
I've got a 2003 Buick Regal with the 3.8L (non supercharged version) with 226621 miles on her. To his car is new to me but before me one owner maintained perfectly and just a great car. Engine is strong, etc. Recently I've been getting a PO446 code, I had been getting an EGR code prior to the PO446. I took out the EGR Valve and cleaned it. That code is gone but I can't seem to shake this 446. I can go a couple of days without seeing it after I reset the fault but it eventually comes back. I notice an exhaust/fuel odor at times, but not always.It does affect the performance of the engine it misses at times, not always. I have done plugs and wires already they helped her stuttering to an extent put it is definitely no to 100% gone. Any suggestions?
-
According to the factory service manual, you may have a problem with the Fuel Tank Pressure Sensor, Vent Solenoid or Canister. The manual recommend start by checking/replacing the Fuel Tank Pressure Sensor. The Sensor is on top of the fuel tank.
Click here to enlarge image -
07 gmc sierra classic have p0442 and p0446 codes what should I check/ replace first? Any suggestions?
-
If you have both codes, then the most common problem is a faulty EVAP Canister Vent Solenoid.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.