Home Diagnosis and TroubleshootingExhaust System P0404 – Has Your EGR Solenoid Gone Bad?

P0404 – Has Your EGR Solenoid Gone Bad?

by Jordan Harris

Have you gotten a check engine light and you diagnosed a P0404 code on your car? If that is the case and you are in this trouble, then you came to the right place because there will be a lot to cover on this issue.

Having a check engine light on your cluster can be something really frustrating to deal with. Why I’m saying this? Well, because it is true. A check engine light doesn’t tell a lot about itself. You need to put up your sleeves and start diagnosing stuff in order to get the right data you need and determine what could be wrong with your car.

For this, you need to ramp up your car knowledge and also learn how everything functions and communicates with each other in a car. This way based on a single code, you will be able to learn where to look and how to overcome a certain problem with your vehicle. But you shouldn’t worry because we are going to help you out.

First, we will introduce you to car diagnostics and how it is done. Then we will cover the P0404 code and learn more about it. After that, we will elaborate more on the P0404 code and learn why it appears. Then we will cover the EGR valve sensor and learn more about it. And then we will dive into the causes of the P0404 Dodge code and the symptoms that this code produces. Later on, we will learn how to diagnose and fix this problem on your car and at what cost. So, if you want to learn more, follow along.

P0404 Code

Now before we dive into more complex topics such as the P0404 Chevy, let’s take a look first at the basics. I bet that there are a ton of people reading this article, who are not quite into cars and want to learn how car diagnostics is done on a car. If you are one of those people, this chapter is for you, if not, you might want to jump to the problem.

Nevertheless, modern car diagnostics is true mastery and requires a ton of skill. It’s not like back in the good old days when cars were really simple and only with a slight tune-up (to learn more, check out our overview of what is a tune-up on a car) you could have fixed most of the issues of running the engine.

Modern cars require a modern approach. They are packed with tech. They include computers, sensors, and whatnot. All this requires some expertise in order for a problem to be diagnosed. But luckily we are here to help you out.

The first and foremost thing that you need to understand is the PCM. This is the Powertrain Control Module. This is basically the car computer that regulates everything. And each car after 1996 has a special port also known as an OBD2 port.

This port serves a purpose so problems like the P0404 Chrysler code be diagnosed. And for this purpose, you will need a special tool. This tool is known as an OBD2 scanner. You plug the scanner in and you scan the car for codes. Then based on the input that you get, you move on to troubleshoot different components with a multimeter.

The scanner and the multimeter are your best friends when it comes to diagnosing problems on modern vehicles and you need to have them in order to fix the P0404 code.

Exhaust Gas Recirculation Control Circuit

Now let’s elaborate more on the P0404 code. What is the meaning behind this code and how we can understand it better in order to sort this problem out? Let’s elaborate.

The definition of this code is “P0404 Exhaust Gas Recirculation “A” Circuit Range Performance”. But what do all these words mean?

Well, this means that you have a problem with the EGR valve. You probably have an EGR valve that is electronically controlled with a solenoid.

What happens in this case, is that this sensor or solenoid whatever you call it, does not work well and is causing you this trouble. But how this code is triggered?

Well, this code is triggered because the PCM has determined that the EGR valve should be open. But actually, it is not open, and based on the feedback it will trigger this code. Or the opposite, if the EGR valve should be closed and the PCM gets feedback that the EGR valve is open, then you again receive this P0404 code.

In this case, you probably have a problem with the exhaust gas recirculation control circuit that is located inside of the EGR position sensor or solenoid.

So, this means that there is some kind of issue inside of the solenoid. But what is this solenoid or sensor in the first place? More about that we are going to elaborate on in the following chapter.

What is important for you is that you should not panic and try to take things seriously and learn more about the EGR system and the EGR position sensor to solve the P0404 code, and that’s precisely what we will discuss next.

EGR Position Sensor

Now let’s learn more about the EGR position sensor to understand more about the P0404 and its causes.

First, we will start with the EGR valve and then we will cover the sensor since they are connected with each other.

The EGR valve as you probably know is an emissions device that opens and closes based on the vacuum that is created. And the EGR valve is a part of the Exhaust Gas Recirculation System. This is a special emission system that is designed to neutralize the Nox particles and also to keep the engine cooler.

This system redirects some of the exhaust gases into the intake of the car. Then these gases are pushed along with the air to fuel mixture to burn in the cylinders.

Modern cars have electronically controlled EGR valves that work with the help of the EGR position sensor or solenoid. This solenoid basically opens and closes the EGR valve. Whenever this component is faulty, it will throw a code like in our case with the P0404 code.

But what are the main causes that can make this component fail and cause you a problem like in our case? Well, that’s what we are going to cover in the following chapter in detail.

P0404 Causes

Now let’s cover some of the causes of the P0404 code, and what could cause this problem in your car. As we mentioned, the EGR position sensor is the prime suspect.

But there could also be some other things that could trigger this situation on your vehicle. And in the next chapters, we will go through all of them in detail so you get a good perspective of what could go wrong and where to look.

1. Malfunctioning EGR Sensor

The first and most common cause of the P0404 code on your car is a malfunctioning EGR sensor also known as EGR solenoid.

This system basically electronically regulates the EGR sensor and turns it on and off whenever it is necessary. What is important to note is that the code P0404 and the solenoid are only included on vehicles with an electronically operating EGR system.

If you have an older vehicle that is running the standard vacuum operating EGR, you don’t have this solenoid and you will not come across this code. And in vehicles that are equipped with this type of solenoid, it can happen that this device starts to malfunction and get stuck in an open or closed position. And this will trigger the P0404 Chrysler.

Another thing worth noting is that this is a solenoid-like device. It means that it has a constant voltage supply from the PCM which is about 12V. So, whenever you test this component you need to make sure that the solenoid gets these 12V of power in order to function right.

But more on this, we are going to elaborate later on when we will learn how to diagnose the P0404 Dodge RAM 1500 code.

2. Problem With The Wiring

The second probable cause for this situation with the P0404 code can be a problem with the wiring. As you probably know, the wiring can fail and short out and this could cause a malfunction of the EGR sensor.

There are a ton of reasons for this. Like using low-quality insulators in some carmakers. The wires simply deteriorate and this will cause a short in the system. This will cause an open ground circuit triggering this code in the process.

Another thing that you need to be aware of is rodents. Wires can be chewed up by these pests and basically end up ruined. So, whenever you have an issue like this, you need to check the wiring as well just to make sure that no wire is damaged. This will guarantee that this could not be the cause for the P0404 code.

3. Bad Connector

The next probable cause that we would like to cover is the problem with the connector of this sensor. As you probably know, connectors are made out of plastic and they can end up damaged.

So, if the connector is loose, it will mean that there is no stable connection inside of the connector. This is why the connector is one of the first things that you want to inspect and check for possible faults.

In addition to this, you need to see if in the connector there is some rust buildup. Some people want to wash their engines with pressure washers and water can creep up inside of these connections and make the wiring short out. So, this is one of the options on the table as well when it comes to solving the P0404 code problem.

4. Broken EGR Valve

The next probable cause for the P0404 code that we would like to cover is a faulty EGR valve. This rarely happens but it can happen sometimes and a bad EGR could trigger this code.

If you didn’t know, EGR valves are notorious for clogging up and you should replace or clean them every 60,000 miles or so. If not, situations like in our case will be present in your can and they could ruin your day.

Replacing the EGR is not cheap like the EGR sensor. But sometimes it has to be done in order for you to solve this problem with the P0404 code on your vehicle. Sometimes this code P0404 after replacing EGR can appear as well.

In this situation, you should consider troubleshooting the sensor and see if it working well. But more on that later on. Also, an EGR valve code reset is useful in this case if you have an OBD2 scanner.

5. Faulty PCM

And the last probable cause for the P0404 code that we would like to cover is the problem with the PCM itself.

As you probably know, the PCM is also known as the car computer, this computer unfortunately can start to malfunction and develop trouble codes without any reason. So, if you suspect something fishy and the codes that you get do not make sense with the condition that you are in, then you should consider inspecting this component and replacing it if it’s faulty. Now let’s move on to the symptoms of this code.

EGR Position Sensor Symptoms

The next topic on our list is the P0404 symptoms. As you probably know, whenever there is a component that is faulty it is producing some symptoms.

Which in our case are the EGR position sensor symptoms. In the following chapters, we are going to elaborate on these symptoms and see how the malfunction of this component translates in real life through these symptoms. So, let’s elaborate.

1. Check Engine Light

If you have an electronically regulated EGR valve and the solenoid has failed, then the check engine light is one of the inevitable symptoms that you will experience.

And you are probably aware of this since you get the P0404 code. But there are also other trouble codes associated with this EGR position solenoid or sensor. These can range from P0403 up to P0408.


So, if you have a code between these two numbers, you are highly likely to be dealing with a bad solenoid that needs to be replaced. Later on, we are going to learn how you can perform this work and diagnose a bad solenoid. Now let’s move on to the next symptom.

2. Rough Idle

The next symptom that we would like to discuss when it comes to the P0404 code and the EGR position solenoid is the rough engine idle.

Whenever this solenoid is not functioning as it should, it will cause problems with the engine idle. If the solenoid is closed, it will not open the EGR and you will suffer from rough idle. Another thing that can cause rough idle is when the EGR is stuck open.

And this is most pronounced. Mainly because there will be too much air in the mix.

The air to fuel ratio will not be ideal and you will suffer from this rough idle condition. So, if you notice something like this, then you should check if you have a problem with the EGR solenoid and if the solenoid is stuck in an open position. Now let’s move to the next symptom of a bad EGR valve solenoid and the P0404 code.

3. Engine Hesitation And Stalling Issues

The last symptom when it comes to the P0404 code that we would like to discuss is the situation when you are experiencing engine hesitation, stalling issues, and engine surging. So, why is this the cause?

This is the cause because the EGR valve is not operating as it should and this is causing the engine to surge, hesitate, and even stall in some cases. And when it stalls it is almost impossible to start the engine and if it does it will go into limp mode.


So, you understand why sorting this issue on your car is this important. Without properly diagnosing it, you will end up with a stalled engine and you will need to call a tow to take your car to a shop.

And frankly, you don’t want to pay so much money for something simple as an EGR position solenoid. But how you can diagnose & fix the P0404 code? Well, that’s what we are going to cover next.

How To Diagnose & Fix The P0404 Code

Now let’s get to business and learn more about diagnosing the P0404 code on your car. How you can tell what is going wrong with your EGR system?

Well, it’s actually quite a simple thing to do. The only thing you will need is a multimeter tool. With this multimeter, you will be able to measure voltage, resistance, and continuity. For our purpose, you will only need the voltage meter.

But the first thing first is to remove the connector from the EGR sensor. Then place the probes on the contacts and see if you get the 12v reference voltage on the multimeter.

If you get 12v then it means that your wiring is good and the EGR sensor/solenoid is getting enough power. Some of the cars should have a 5v reference voltage. So, it really depends on the make and model.

The next thing you want to do is to see if the solenoid is activating. For this you will need a 12v power supply, you can use your battery to test this out. Just use alligator clips from the positive and negative terminal of the battery to the solenoid. If the solenoid works, you will be able to hear a slight click.

And the last thing that you would want to test is to see if you have a vacuum. For this, you need to remove the solenoid from the vehicle and apply vacuum pressure. It should be closed if it’s good.

So, no air should pass through, if air passes it means that the solenoid is blown. Once you are done and replaced the solenoid, just take your scanner and perform an EGR valve reset code to clear the codes. How you can test these methods you can check in the video above.

Cost To Fix The P0404 Code

Now let’s cover more on the cost to fix the P0404 code. How much money can you expect to pay in order to sort out this problem with your car?


Well, the answer to this question is that this depends. If the problem is in the EGR solenoid or the EGR valve itself, or if the problem is in the solenoid you cannot expect to pay more than $200 with all the diagnostics, parts, and replacement involved.

If the EGR valve is bad, then you will have to pay about $350 to replace it.


In this article, we have covered quite a bit when it comes to tackling this problem with the P0404 code on your car.

First, we learned the meaning of this code and what it represents. Then we learned the main causes, symptoms, and how to diagnose, and fix the problem. Lastly, we elaborated more on the costs involved in sorting this problem out.


Now let’s answer some frequently asked questions.

What Is P0404 engine Code

This code is indicating a problem with your EGR system. More precisely, with your EGR solenoid. This code is only present on cars that come equipped with an electronically controlled EGR valve. So, the component in question when it comes to this code is the EGR solenoid.

What Does Code P0404 Mean

This code means that there is a problem with circuit A of the EGR solenoid that activates the EGR valve. This electronic component has probably malfunctioned and is causing this error code to appear on your cluster.

How Do I Fix Error Code P0404

The way you can fix this code is to replace the EGR solenoid/sensor with a new component. This solves the problem in most cases when this code is appearing in a vehicle. If not, check the wiring as well as the PCM.

Will A Bad EGR Valve Throw A Code

Yes, it will throw a code. The computer is smart enough to detect anomalies when it comes to the work of the EGR valve, even though this valve is not directly connected to the computer itself. But based on the input from other sensors the computer knows that this EGR valve malfunctions.

How Much Does A EGR Valve Cost

The EGR valve on average costs about $250 to $350. It is not that expensive part and you will probably have to replace this component at least once in your car ownership since this component tends to get clogged and fail.

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