Chevy Trailblazer P0449 Code Diagnosis: EVAP System

The most common issue is the Chevy Trailblazer The Code P0449. This is your trouble code. It is the reference number given when you connect Trailblazer to an a OBDII scanner. The evaporative emission control system is P0449. This code is often found with or related to P0420,P0446 and, very rarely, P0440.

P0449: Evaporative Emission Control System Vent Valve/Solenoid Circuit Malfunction

Your Trailblazer's driveability is generally not affected by P0449. Certainly anytime the service engine soon light is on, it’s good to deal with it as soon as possible though. A scanner that is very accurate will allow you to identify if the valve works correctly. They are common in shops. There’s a link towards the bottom the page on exactly how to perform that procedure. This article will show you how to diagnose and fix the problem.

Chevy Trailblazer P0449 Definition

The universal OBDII code P0449 can be used to diagnose trouble codes. It means that no matter what make or model vehicle it is, P0449 will be the same code (Trailblazer, or not) as long as the vehicle was made after 1996.

The P0449 code indicates that the solenoid or valve that controls the evaporation systems isn't working properly. Depending on your vehicle's model, the EVAP cycle fuel vapor out of the tank into an intake manifold. If the system fails to function properly, fuel vapor will not be removed.

ECM (Engine Control Modul) detected a fault within the circuit controlling the vent to release fuel vapor. Soon, the service engine will follow this up.

Chevy Trailblazer P0449 OBDII Code Symptoms

A P0449 Code will not usually be associated with other noticeable symptoms. The smell of gas The service engine soon light. It is possible to notice a slight dip in fuel economy.

Particular attention should be paid to the fuel tank or fuel filler tube smell.

The EVAP system is responsible for fuel vapors. If these vapors are leaking from the system, you’ll often smell them faintly while operating the vehicle.

Trailblazer Trouble Code P0449

P0449 code can trigger on your Chevy Trailblazer for many reasons. These are some of the more common issues that can trigger the P0449 code. Here's a video explaining the process.

• Fuel Cap– A bad fuel cap can cause the code to be thrown for sure. Often, you’ll get a message informing you that the fuel cap is off even when it is on. It may be worth your time to get that message and a P0449 to ensure you don't waste any money.
• EVAP System Hose– The hose that carries the fuel vapor from the fuel tank to the intake manifold can begin to leak. The P0449 code will be generated. You should look for a hole or a tear in the code. This is the main problem that can cause the code.
• Vapor Canister Purge Valve– One of the most common causes of the P0449 code is the vapor canister purge valve. It’s really easy to replace. There are some clips you will need to look for and then remove. Here’s How to check a purge device (YouTube).
• Trouble with Fuse or Wiring– If the wiring going to the valve has been compromise, it’ll lead to the P0449.
• Fuel Tank Sending Unit– It is possible for the gasket that attaches the fuel sending unit to the gas tank to go bad. It can lower the tank pressure, which could throw out the code.
• Fuel Filler Neck– There is often a gasket where the fuel filler neck connects with the gas tank. The gasket may dry out especially if the vehicle is in dry conditions. When it dries out, the fuel tank can’t hold pressure anymore, it may erroneously throw P0449.

P0449 Diagnose- Chevy Trailblazer

To diagnose the problem with your Chevy Trailblazer's P0449, a mechanic will have a variety of tools at his/her disposal. These are some of the common diagnostics that can be done for the code.

• To ensure that the cap can withstand pressure, the mechanic will check it. If you are getting a warning that your gas cap is off, even when it’s on, replacing it will more than likely clear this code.
• The mechanic will check to make sure there are no other codes. It is easier to diagnose problems if there are more codes. That’s because when they appear together in certain combinations, there will often only be only a few conditions that will throw any combination of codes at one time.
• Once the mechanic has determined the trouble codes associated with P0449, he or she will usually Take a look at the EVAP system. It includes the line, purge valve and canister.
• Monitoring and checking the fuel tank pressure is a must.
• After for the checks and fixes listed above, the mechanic will perform two tests: A smoke test, and they’ll use a scan tool to confirm that the EVAP solenoids and valves are operating properly.

Have you got trouble with your computer? Here’s a Video with super technical content It is very detailed in diagnosing P0449.

Most common P0449 fixes

These are some of the most popular Trailblazer P0449 fix:

• Replacement of gas cap
• Replacing EVAP lines
• Vent valve replacement
• Wiring repair

It is best to begin with the gas cap, and then work your way up to the fuel tanks. The gas cap is the most difficult and cost-effective item to replace.

Here’s a great video on How to check your gas cap.

We wish you all the best in finding out why your Chevy Trailblazer is throwing the P0449 code. We trust this helped. Please feel free to add anything below.

Do you consider P0449 to be a serious concern?

While P0449 is not going to cause the Trailblazer’s engine to stop running, it should not be treated lightly. There could be fuel contamination. Check your tank regularly to make sure there is no fuel leaking. It is best to have it checked and/or dealt with immediately.