Have you noticed that your temperature gauge went crazy and also the check engine light has shown along with the P0118 code? Well, if that is the case, then you are at the right place because there will be a lot to cover on this topic.
Having a problem with the temperature of your car can be something that you don’t want to happen. Because whenever there is a spark, there will be a fire. And so is the case in this situation. The slower you try to address this problem, the worse it will get and you will basically end up with a damaged engine. And you don’t want that.
This is why you need to put up your sleeves and learn how to diagnose and troubleshoot stuff. Only this way you will be able to sort out this issue and overcome it really quickly before it gets worse and your engine damage itself by running in this condition.
First, we will learn more about the basics of car diagnostics and how it is done the right way. Then we will move to the problem with the P0118 code and understand why it is appearing. We will cover all of the causes as well as the symptoms that will be present. Then after, we will move on to diagnosing this stuff and the costs involved in this work. Lastly, we will answer some frequently asked questions. So, if you want to learn more, follow along.
P0118 Code
Now before we dive into the P0118 code and learn more about its definition and how it is represented, let’s first focus on the basic stuff. I bet that there are people who are reading this article and not that well experienced when it comes to diagnostics and want to learn more about it and how it is performed.
When it comes to car diagnostics it is worth noting that this is a real skill that doesn’t grow up on a tree and you will need to spend hours and hours to perfect it. All this by reading repair manuals, watching videos of how this is done, and also experimenting with your car.
You need to be proactive when it comes to this stuff and you need to be a person that loves problem-solving. Only by doing things like this, you will be successful when it comes to diagnosing problems with cars.
Not to mention that you will also need some tools that will help you out when it comes to solving these problems. And the most important tools for you are the OBD2 scanner and the multimeter.
With the OBD2 scanner, you will be able to diagnose the codes and get the input from the computer. Then with the multimeter, you can move on and bench test some of the components and see what type of values they are producing.
Without bench testing components, you will possibly replace good components. And you don’t want to spend a ton of money on components that are actually in good condition. But what about the P0118 code and its definition? Well, more on this in the next chapter.
P0118 Engine Coolant Temperature Circuit High Input
Now let’s get to business and that is the problem with the P0118 code, to understand the definition and meaning of this code. So, what is the definition of this code?
The definition of this code is “P0118 Engine Coolant Temperature Circuit High Input”. And what does this mean?
Well, this is a DTC code also known as a trouble code that indicates a problem with your coolant temperature sensor. More precisely a high voltage to this sensor. And what is this coolant temperature sensor in general?
Well, this sensor basically makes sure that the temperature of your coolant is constantly observed by the PCM, and based on these temperatures, you get readings on your cluster as well as the engine adjusts the work based on this input. But how this sensor works in reality?
How this sensor works is really simple to explain. There is a constant voltage to your coolant temperature sensor from the PCM. This voltage is about 5V.
Then after the car starts and the coolant warms up, this voltage will drop the hotter the car gets. What happens in your situation is that this voltage of the sensor does not drop below 5V but it gets even higher. So, the computer thinks that the car engine is really cold.
And this is not good reading. With this reading, you will experience some symptoms that we are going to discuss later on in the article.
What is important for you is not to panic and try to understand how this coolant temperature sensor works and learn the coolant temperature sensor diagram. And that’s what we are going to cover before we dive into the causes of the P0118 code.
Coolant Temperature Sensor Diagram
Now before we jump into the causes for this P0118 code, let’s cover more about the coolant temperature sensor diagram.
On most cars out there coolant temperature sensor has two wires. Meaning that it is a 2 wire temp sensor coolant temperature sensor wiring diagram. One of the wires is the ground wire which is usually black and the yellow wire which is the signal wire. This signal wire passes that 5V of power constantly.
Then based on the temperature inside of the coolant, the voltage should drop and this will give the computer the right readings when it comes to the temperature of your coolant inside of the engine.
There are also sensors with three wires. But they are less common and are used mainly in Volkswagen models.
As you can see, the diagram is really simple for the ECT or engine coolant temperature sensor. So, you should not get confused. But you shouldn’t worry because we have just started. In the following chapters, we are going to cover all of the causes for the P0118 and understand them better.
P0118 Causes
Now let’s cover some of the causes of the P0118 code. As we noted, there are more than a few things that could go wrong and trigger this type of code.
What is worth noting is that not all of them are connected to the sensor itself. So, if you want to learn more about them. Please follow along.
1. Faulty Coolant Temperature Sensor
The first and most common cause for this problem with the P0118 code that we are going to cover is a faulty coolant temperature sensor.
The sensor can fail internally and not work at all. This is one of the most common reasons for this problem with the P0118 code.
A lot of people replace the sensor even without checking the values that it produces. Which in some cases is wrong because in some cases the sensor is in good condition but something else could be causing the problem.
When testing this sensor you need to make sure that it reacts to different types of temperatures based on the spec sheet that was created by the factory. Later on in the article, we are going to explain how you can bench test this sensor in different temperatures and learn how the sensor should behave in different conditions. Now let’s move to the next probable cause for the P0118 code.
2. Bad Internal Electrical Circuit Of The Coolant Temperature Sensor
The second most probable cause for the P0118 code is an internal short in the sensor electrical circuit. This is very frequently the case when you experience higher voltages than normal.
The internal electrical circuit of the sensor is basically malfunctioning and this is causing a lot of trouble for you as a car owner.
There are surges of power and the sensor is very unstable, causing you a ton of trouble and problems like in the case with the P0118 code.
So, whenever you have an issue like this, you will have to test the sensor and see how it works in different temperatures. More on that later on in the article where we will elaborate more on depth how to test the coolant temperature sensor. Now let’s move on to the next probable cause for the P0118 code.
3. Bad Ground Connection Between the Sensor And The PCM
The third most common cause is a problem with the wiring. There could be a bad wiring connection between the sensor and the PCM of the car.
Whenever there is a bad ground connection, there will be short in the system and possibly increased voltages like in our case with the P0118 code. This is a clear example that you need to test your ground connection from the connector to the PCM.
This way, you will be sure that you run the ground wire and that everything works well. If not, the problem will not be fixed and you will continue to have troubles with this P0118 code. Now let’s move on to the next probable cause.
4. A Short In The Voltage Wire Between The Sensor And The PCM
The next thing that we would like to cover is a short in the voltage wire between the PCM and the sensor.
This short can be caused by damaged wiring, similar to the previous problem that we covered above with the ground wire. The wiring needs to be checked and you need to be sure that you get the 5V of power from the connector.
If this isn’t the case and the voltage is higher than usual, you might be having problems with the wiring and the wires that go from the connector to the PCM have to be checked so you can determine what is causing the issue.
Most likely there is a damaged wire that is causing the system to short out and this consequentially causes spikes in voltage and uneven voltage supply. So, check your wires and determine if some of them are bad, and fix them accordingly before you connect the connector for the sensor. Either way, your computer will again throw the P0118 code.
5. Bad Connector
The last thing that we would like to cover with the P0118 code causes is a problem with the wiring connector. The wiring connector for the sensor is one of the first things that could fail and cause you trouble like this.
So, whenever you test the car, it is worth giving the connections a good cleaning with a special solution intended for electrical connections. Make sure that there is a proper contact between the connector side and the sensor side and this will guarantee that you have a decent connection that will prevent future problems like in our case with the P0118 code.
But what about the symptoms of this coolant temperature sensor? Well, more on them in the following chapters.
Bad Coolant Temperature Sensor Symptoms
As we covered the causes for the P0118 code, now it is time to focus more on the symptoms of this code. Also known as the symptoms of the coolant temperature sensor.
Knowing the symptoms will help you come to the conclusion if you are dealing with problems with this coolant temperature sensor. And more on the symptoms we are going to cover in the following chapters where we will elaborate on them in great detail and learn everything you need to know. So, if you want to learn more, follow along.
1. Check Engine Light
The first symptom when you have a bad coolant temperature sensor will be the check engine light and the P0118 like in our case. Since if it wasn’t for this code, you wouldn’t have been here already.
But what if I told you that there could also be other codes that are closely related to this sensor. Also, when you scan the car for codes, there will probably be other codes that will appear along with the one that we cover in this article.
Some of these codes include P0115, P0116, P0117, P0118, P0119, P0125, and PO128 code (such as the P0128 Jeep code). All of these codes are closely related to this problem, so if you have one of these codes, make sure that you further diagnose the issue. Now let’s move on to the next probable symptom for the P0118 code.
2. Engine Has Hard Starting
The second symptom that we will cover will be the difficulties to start the engine. Believe it or not, when this engine coolant temperature sensor doesn’t perform well, the engine will be really difficult to start.
You will continuously crank the engine until eventually starts. A lot of people would consider this as a problem with the crankshaft position sensor but this isn’t always the case. Like in our example, this problem can be caused by a bad coolant temperature sensor as well.
This is the case because the PCM is not able to record the coolant temperature and it basically acts like there is freezing cold outside. The sensor is not sending the right data to it and the computer is really confused and has trouble aligning the parameters. This is why you need to diagnose the P0118 code and fix it before it becomes too serious.
3. Engine Will Run Rough On Startup
The third thing that we would like to cover when it comes to the symptoms of a bad coolant temperature sensor is a situation when the engine runs really rough on startup.
You will notice this situation when the engine runs rough, throws black smoke from the exhaust, and misfires before it finally settles down after reaching the right operating temperature.
This is another symptom that happens as a consequence of the P0118 Nissan code and the bad engine coolant temperature sensor. This means that you need to move on to diagnosing and sorting out this problem as quickly as possible if you want to avoid any further consequences to your engine by running your engine like this. Consequences can get really detrimental if this continues like that in the near future.
4. Poor Fuel Economy
The last symptom that we are going to cover when it comes to the engine coolant temperature sensor and the P0118 Jeep code, is the increase in fuel consumption.
When the engine runs with a problematic engine coolant temperature sensor, it will cause problems like these. But why is this the case?
Well, it is the case because the engine thinks that the outer temperatures are really low. In these situations, the computer will decide to throw additional fuel into the mix and this will result as we mentioned previously, in black smoke, rough engine work, and poor fuel economy of your vehicle.
And this will be the case until you decide to diagnose the problem and sort the issue with your car. How you can do this work, we are going to explain in the following chapter more in-depth.
How To Diagnose & Fix P0118
As we covered the P0118 Dodge code and we learned the causes as well as the symptoms that are associated with this code. Let’s now move on to diagnosing the code on your car and what is causing it.
There are two things that you will want to test. The first thing is the wiring and the second thing is the engine coolant temperature sensor. First, we are going to explain the wiring and then the sensor.
The first thing to test is the connection. For this, you will need a multimeter and turn the tool to measure volts. Then remove the connector and place the probes of the multimeter on the two pins of the wiring connector. Then turn on the ignition and see if you are getting about 5V if you are getting 5 volts, then the signal wire is good. The next thing you will need to test is the ground connections. How this is done you can check in the video.
The second thing that you will want to test is the sensor itself. You need to turn and measure the resistance that this sensor is producing. This means that you need to tweak your multimeter to measure ohms.
At temperatures of about 68 degrees Fahrenheit, it should produce between 2000 and 3000 ohms. On temperatures at about 194 degrees Fahrenheit, this should drop to something between 200 to 300 ohms. More on how these tests are performed can check in the video.
Overall, the testing process is really simple. The only thing you will need is a good multimeter and a good OBD2 scanner that will work on most cars. Now let’s elaborate more on the costs to fix the P0118 code.
Cost To Fix The P0118
As we elaborated everything on the causes, symptoms, and the diagnostics process for the P0118 Chevy code, let’s now move on to learn the costs involved in this work.
The base costs for diagnostics for this problem will probably be around $120. Then comes the cost for the part which is relatively affordable. The coolant temperature sensor on average costs between $55 and $90. The labor will cost you about $100 to $150.
Conclusion To P0188
In this article, we have covered quite a bit when it comes to the P0188 Honda code. First, we learned the basics of car diagnostics and how it is performed on a car. Then we focused on the problem and we elaborated the code.
After we learned the causes of this code. As well as the symptoms that are associated with this engine coolant temperature sensor. And we learned how to diagnose it and fix the problem.
F.A.Q
Now let’s answer some frequently asked questions.
What Is The Code P0118 Mean
This code means that you have a problem with your coolant temperature sensor, more precisely high circuit input in your coolant temperature sensor. Meaning that the input is higher than 5V. This could be attributed to a bad coolant temperature sensor or bad wiring or bad connector.
What Causes P0118 Code
This code is most often caused by a bad coolant temperature sensor. Replacing this sensor will hopefully fix the issue. If not, then there is a problem with the wiring. Make sure that you check both the signal and the ground wire of your connector and see if you get the right readings.
How Do I Fix Code P0118
Fixing this code is relatively simple. First, you need to test the ground connection. Then you will need to test if you get the right voltage output through the signal wire. Lastly to test the sensor and the resistance that you get. All these procedures are essential to make if you want to determine if the problem is in the wiring or the coolant temperature sensor itself.
