GMC Acadia P0449 Code Diagnosis: EVAP System

This is a very common problem with the GMC Acadia The Code P0449. This is your Acadia's trouble code. OBDII scanner. The evaporative emission control system is P0449. This code is often found with or related to P0446 and P0420.

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

Your Acadia'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. You can also use a scanner to check if your valve is working 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 Acadia P0449 Definition

The OBDII universal trouble code P0449 is the one. The code can be used regardless of the make and model of the vehicle.

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 Modul) detected a problem with the circuit controlling the vent to release fuel vapor. Soon, the service engine will follow this up.

GMC Acadia P0449 OBDII Code Symptoms

The P0449 code is usually not accompanied with any other symptoms than those listed. Smells like gas The service engine soon light. The slightest drop in fuel economy may also be noticeable.

The fuel tank and fuel filler tubes should smell particularly strong.

Fuel vapors are dealt with directly by the EVAP system. If these vapors are leaking from the system, you’ll often smell them faintly while operating the vehicle.

Acadia P0449 Troublecode Causes

P0449 code can trigger in GMC Acadia for many reasons. Below are the top problems that could trigger this code, along with an excellent video.

• 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 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/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. 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 Diagnostics- GMC Acadia

The mechanic will have a lot of different tools at their disposal in order to determine the cause of P0449 on your GMC Acadia. 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 Check out the EVAP System. These include the line and purge valve.
• Monitor and check the pressure in your fuel tank.
• 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 Super technical video It is very detailed in diagnosing P0449.

Most common P0449 fixes

Below are the top Acadia P0449 solutions:

• Replacing the gas cap
• Replacement for EVAP Line
• Vent valve replacement
• Wiring repair

You should start with the gas caps and move on to the fuel tanks. This is because the gas caps are the easiest to replace and the least costly.

Here’s a great video on How to test your gas tank.

You will need to find the root cause of your GMC Acadia throwing the P0449 code. This should help. You can add any additional information by leaving a comment.

Are P0449 Serious Concerns?

While P0449 is not going to cause the Acadia’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. You should immediately take it in for repair or replacement.