P0440 Chevy – Is This EVAP Code Serious?

P0440 Chevy – Is This EVAP Code Serious?

August 25, 2022 0 By CarGuy

So, you got the check engine light on the cluster and you diagnosed the P0440 Chevy code? Well, if this is the case, then you are at the right place because there will be a lot to cover on this topic where we are going to learn all about tackling this annoying problem on your vehicle.

Doing a proper research on an issue that is troubling you is key. Why so? Well, there are a ton of really incompetent mechanics out there that often misdiagnose stuff on cars and this misdiagnosing often costs the owner hundreds of dollars more. Sometimes even thousands.

So, you need to really be self-aware that you can also do things by yourself. Especially problems that are rather simple to tackle such as vacuum leaks like in this case. But this is why we are here to help you out and make sure that you sort out the problem as soon as possible without major headaches.

First, we are going to dive into car diagnostics and learn more about the methods and tools that are used nowadays to diagnose problems on cars, then we will cover the P0440 Chevy meaning and also the main causes, symptoms, and how to diagnose the problem. And also how much it will cost you to fix the issue. So, if you want to learn more about this problem and how to overcome it, follow along.

Introduction To Car Diagnostics

Now before we dive deeper into the P0440 Chevy problem, let’s first take a look at the basics of modern car diagnostics. Why do we find this useful? Well, there are a ton of beginners who are reading this article and are not into cars. So, they really need a good starting point.

So, what is modern car diagnostics? Well, we can say that this type of diagnostics is rather different than the old-school approach where the mechanic relied solely on his experience when it came to solving problems.

Modern cars are so much more than the old classic cars. Modern vehicles are all computerized where one main computer is regulating a ton of different sensors throughout the vehicle. This computer is also known as PCM or Powertrain Control Module. In some instances, you might come across the ECM or ECU abbreviations. But generally, they are the same deal.

Nevertheless, what is important to note is that cars after 1996 come standard with OBD2 ports. This is generally a car diagnostics port. In this port, you can connect an OBD2 scanner and scan the car for possible codes. This scanner makes solving problems a lot easier and really once you get a hold of it, it’s a breeze to use.

The second tool that you will need is the multimeter. With the multimeter, you will be able to measure different properties. Such as voltage, resistance, and continuity. All, these properties are important when you diagnose sensors.

These two tools are complete lifesavers that will save you thousands of dollars in the long run. And what is good is that you can get both of them for less than $100. But enough on the tools, let’s move on to the P0440 Chevy problem.

P0440 Chevy Meaning

Now since we learned the basics of car diagnostics and learned how it is done and what are the tools needed for this practice. We can slowly move on and start learning about the problem, which is the P0440 Chevy code. What is the P0440 code meaning? Let’s elaborate.
The definition for the P0440 code is “Evaporative Emission Control System Malfunction”. So, what does this mean in the first place? Is this issue very serious?

Well, it is not quite serious of a problem. What is good with this code is that you can keep driving the car, even though you get this check engine light and the code P0440.

So, you can sleep well and fix the problem when you can. Even if you drive the car for thousands of miles, you might not even feel some of the symptoms. But in some cases, the symptoms can be rather aggressive. It really depends on what is causing this problem to appear in the first place.

But what does this code means, what is the evaporative emission control system? Well, this is a special system that modern cars have. More on how it works we are going to cover in the following chapter where we are going to learn from which components this system consists and how it functions in the automobile.

Knowing how everything works will be really useful when it comes to tackling problems like in this case with the P0440 code. So, you don’t want to miss that.

How Does The EVAP System Works?

We learned the P0440 Chevy meaning, and we think that before we dive into the causes and symptoms that this problem gives, it is better to discuss how the EVAP system works in general.

I bet that there are a ton of people reading this article who are not into cars are not quite familiar with this system. So, this chapter is dedicated to them.

We learned that this is the evaporative emission control system. So, what this system controls overall? Well, if you didn’t know, when you go to the gas station, you pour gas. And gas tends to evaporate inside of the tank and create pressure.

So, what this system does is that it keeps the tank pressurized all the time and does not allow these fumes to escape. Then, it collects the fumes and redirects them into the intake manifold in order to burn.

This system basically is consisted of the gas tank, gas cap, charcoal canister, purge solenoid, and vent solenoid.

So, the harmful fumes are collected from the gas tank, and then they are redirected to the charcoal canister. The charcoal canister basically absorbs these fumes with the help of activated carbon.

Then from the charcoal canister, the fumes are sent to the intake of the engine. This system communicates with the PCM and when the PCM determines that it should purge the system, it will activate the purge valve. Also known as the purge solenoid.

This process has to be done very effectively because if it’s not, you will have a check engine light as in this case with the P0440 which means a general malfunction of the EVAP system. The causes of this problem can be many and in the following chapters, we are going to cover them in-depth.

P0440 Chevy Causes

Since we covered more about the basics of the P0440 Chevy Silverado problem, let’s now move on and learn more about the causes of this problem.
Let’s take a look at the main reasons why you have a P0440 code on the cluster. Knowing the causes will help you determine where to look in order to solve your problem. So, pay close attention while we cover the main causes of this issue.

1. Bad Gas Cap

Now let’s dive into the causes of the P0440 Chevy Equinox. And the first reason for this type of problem is definitely the gas cap. So, why is this the case?

Well, as we mentioned previously, in order for this system to work, you need to have a proper gas tank pressurization.

And when the gas cap doesn’t seal well, you simply cannot achieve enough pressurization for the EVAP system to work.

So, what happens in these situations is that the system has a vacuum leak. And then you get the P0440 Chevy Trailblazer code and you end up with a problem. So, this is one of the first things that you want to check out when it comes to sorting this problem on your Chevy.

2. Leaking Hose In The EVAP System

The second most common reason for the P0440 Chevy Cruze is the leaking hose. The EVAP system consists of many different plastic hoses that go from the rear of the car to the front.

And what happens is that plastic can break and cause a vacuum leak. Even if it’s a small one, it will be enough to ruin your day.

And these leaks are very difficult to diagnose. Mainly because they are simply invisible. So, what people do is get a smoke machine and test the system with smoke. Now let’s move to the next probable cause.

3. Bad Purge Valve

The next very common reason for P0440 GMC is the purge valve of the EVAP system. This component is also known as the purge valve solenoid. So, what this component does?

Well, this component has a simple task, and that is to open and close when needed. It opens to purge the EVAP system whenever there is big pressure inside of the system. When this solenoid opens, it simply redirects the gases to the intake of the car and then into the combustion.

What can happen is that this solenoid can stuck in a fully open or fully closed position. Causing a ton of headaches in the process. The code P0440 Chevy Suburban is just only one of the possible codes that could appear when you have a situation like this inside of your car. Now let’s move on to the next cause.

4. Bad Vent Control Valve

Now let’s move on to the next very common cause for the P0440 Chevy Tahoe, and that is the bad vent control valve. So, what is this vent valve?

Well, this is basically a component that functions the same as the purge valve. This means that this is also a solenoid device. But what it does actually?
Well, the hydrocarbons get trapped inside the charcoal canister. And what this valve does, is release clean gases into the atmosphere.

But in some cases, it can end up stuck open or closed and cause problems like in our case with the P0440 Chevy Impala code.

5. Bad Charcoal Canister

The next probable cause for the P0440 Chevy Malibu is the charcoal canister itself. These charcoal canisters are produced from plastic.

And as we all know, plastic can crack and cause leaks to develop. So, this will cause you to lose vacuum. This happens very rarely but it still can happen. Especially if you accidentally damaged the charcoal canister while driving. Considering that this device is often installed next to the rear bumper. It is very easy to damage it, especially if you drive off-road.

6. Bad Fuel Pump Seal

And the last in our list of causes for the P0440 Chevy Traverse code is the bad fuel pump seal. So, why is this the case? Let us explain.

If you didn’t know, each car has a fuel tank and the fuel pump is mounted right on top of the tank. Between the pump and the gas tank, there is a rubber seal. And what can happen is that rarely in some cases, this seal can leak air and you could lose the vacuum in the EVAP system. Triggering a P0440 Chevy Tahoe code.

So, here we finish the P0440 code causes. But what about the symptoms? Let’s cover them in the following chapter.

P0440 Chevy Symptoms

Now let’s dive into the symptoms of the P0440 code. So, what are the symptoms that you can expect when you have an issue like this?

Well, obviously the check engine light will be present on the odometer and you will have to diagnose it. The P0440 code if diagnosed doesn’t mean a lot.

Still, you need to make sure to check for other codes such as the P0441, P0442, and so on. These error codes are more precise and will give you better input.

Except for the check engine light, other common symptoms can include the smell of fuel vapor inside of the cabin if you have a leak somewhere. Or the smell of fuel vapor where the gas cap is.

There are no other major symptoms concerning this issue. Unless the purge valve is stuck open and you have unmetered air entering the intake. Then you will have symptoms like rough idle, lean air to fuel mixture, and frequent misfires.

How To Diagnose A P0440 Chevy Code?

So, how you can diagnose and fix the problem with the P0440 code? Well, as we mentioned previously, the code itself does not mean quite a lot.

You need to check if you have other codes as well. If there are no codes, then you should try to replace the gas cap. This often solves the problem.

If the problem still persists, then you would want to do a smoke test. Doing a smoke test with a smoke machine is really good when it comes to diagnosing problems like the one in our case.

Every shop has a smoke machine and mechanics can do this procedure in no time. So, if the gas cap does not fix the code, then this will be your next step.

Also, if you suspect on the purge valve or vent valve, you can test them with a multimeter and see if they work. Overall, that’s all when it comes to diagnostics and fixing the problem.

Cost To Fix This P0440 Code

So, we learned how to diagnose a P0440 Chevy Silverado code. Now let’s take a look at how much money can you expect to pay to get this thing sorted out. Will it be expensive or not?

Well, the answer to this question really depends. Many people sort this problem out by replacing the gas cap. And this only cost a few dollars. If the problem is a purge valve or vent valve then you can expect to pay up to $30 for its replacement.

P0440 Chevy

Also, this really depends on where you take your car to fix. Some places are rather expensive and they charge an arm and a leg. In the best-case scenario, you can expect to pay about $120 for the diagnostics and extra for the parts if you need something to replace.

Overall, it is not a really expensive problem to fix. And with a little bit of troubleshooting and ingenuity, you can also fix it by yourself at home. So, it mostly depends on you and your skills. Also, this is a good project for novice mechanics because there isn’t quite a lot to mess up since this EVAP system is pretty straightforward. Now let’s conclude this article about the P0440 Chevy code.

Conclusion To P0440 Chevy

In this article, we have covered quite a bit when it comes to the P0440 Chevy. First, we learned the basics of car diagnostics and learned how this procedure is performed on modern vehicles.

Then, we elaborated on the problem and learned how it is represented and the meaning of the P0440 code. After we elaborated on the problem, we covered the main causes for this code which were the gas cap and the purge valve solenoid. After that, we covered the symptoms that this code produces, and except for the gas odor in some cases and the check engine light, there isn’t much to it.

Lastly, we covered how you can diagnose and fix a P0440 code and also how much money can you expect to pay to sort out this problem at a shop.