GMC Yukon P0449 code Diagnosis : EVAP system

The most common problem is the GMC Yukon Is the Use code P0449. This is your Yukon's trouble code. OBDII scanner. It deals with the evaporative emissions management system. It is frequently found alongside, or closely related to, other codes such as P0420 and P0446.

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

Your Yukon's drive-ability 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.

GMC Yukon P0449 Definition

P0449 stands for a universal OBDII Trouble Code. It means that no matter what make or model vehicle it is, P0449 will be the same code (Yukon or otherwise) 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 which vehicle model you have, the EVAP system converts fuel vapor from your gas tank to the intake manifold or charcoal canister. If the system fails to function properly, fuel vapor will not be removed.

ECM (Engine Control module) has identified a problem in the circuit that controls the vent which releases fuel vapor. Soon, the service engine will follow this up.

GMC Yukon P0449 OBDII Symptoms

A P0449 Code will not usually be associated with other noticeable symptoms. Smells like gas The service engine soon light. The slightest drop in fuel economy may also be noticeable.

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

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.

Yukon P0449 Trouble Code Reasons

P0449 code can trigger in GMC Yukon 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. You may not get the message but a P0449. This will save you time and money.
• EVAP System Hose– The hose that carries the fuel vapor from the fuel tank to the intake manifold can begin to leak. This can lead to the P0449 error code. It should have a tear or a hole. This is the leading cause of 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. You will need to locate and take out a few clips. Here’s How to check a purge device (YouTube).
• Wiring and Fuse Problems– 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. This could cause a drop in tank pressure which can throw off 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 Diagnoses- GMC Yukon

The mechanic can use a range of tools to determine the cause of P0449 on your GMC Yukon. These are some of the common diagnostics that can be done for the code

• A mechanic will examine the gas cap and verify that it is able to withstand high pressure. 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 usually 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. These include the line and purge valve.
• 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.

Are you still having problems? Here’s a Video with super technical content It is very detailed in diagnosing P0449.

The Most Popular P0449 Fixes

These are some of the most popular Yukon P0449 solutions:

• Replacing the gas cap
• Replacement for 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 test your gas tank.

We wish you all the best in finding out why your GMC Yukon is throwing the code P0449. This should help. Please feel free to add anything below.

Do you consider P0449 to be a serious concern?

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