Check Engine Light – Meaning and Why It Comes On

Meaning and Causes of check engine light

Check Engine Light – A usual feeling most drivers would have if the Check Engine Warning light should come on is that of dismay and some would even panic.

The truth of the matter however is that sometimes, the check engine warning light coming on is only indicative of minor issues that can be easily fixed. That notwithstanding it should not be ignored and the best cause of action is to immediately try to ascertain the reason for the light coming on and fixing it as soon as possible to avoid further complications.

In this article, we will be discussing at length the meaning of Check Engine Lights, why they come on and how to handle the issues that they point out. We strongly believe that as a driver, you will find this write up really helpful.

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What Does The Check Engine Light Really Mean?

So the Check Engine Light comes on and you are wondering what this means. See it as your car trying to communicate with you and drawing your attention to a fault with your engine’s electrical system.

There are various reasons for this, it can be as a result of a faulty engine sensor, an issue with your emissions control system or any other damaged part in your engine.

Car manufacturers in 1996 started fitting all car systems with the OBD-II protocol. What this protocol does is that it provides a list of diagnostic trouble codes. These diagnostic trouble codes can then be read via a universal connector.

Like we said earlier, the check engine warning light would come on if your vehicle’s computer notices a problem with your engine. You should however be aware of the fact that the light differs depending on the choice of the automaker.

So the check engine light of your car could be yellow while that of your friend with another make of car would be orange. The colour options are usually orange, amber, or yellow light.

Another thing that you should take note of is how the light comes on. Generally when the light comes on it means that there is an issue that you have to take a look at, but if the light comes on and it shines steadily then the issue is not an urgent one.

That does not mean that you should ignore it, it is still advised that you get a professional to check it out as soon as possible.

If on the other hand, the light keeps flashing on and off, then the issue is a critical and urgent one. If you are driving you should immediately pull over and contact a mechanic.

We have to clarify here that the check engine light is not the same as the service light. The service light displays a wrench like shape and says either “Service Now” or “Service Soon.” It is simply a reminder regarding a need for maintenance.

Why Is My Check Engine Light Coming On?

The check engine warning light coming on can be as a result of different issues with your engine ranging from issue with the emission control system such as a bad oxygen sensor or MAF sensor, issues with the ignition such as bad spark plugs or ignition coils, etc.

Some of the issues that the check engine warning light is trying to draw your attention to could be benign and there are times when it will be serious issues that you should see to immediately.

We have outlined below, five of the most common issues that will make your check engine light to come on.

They are as follows:

Defective Spark Plugs or Wires

The spark plugs are what supplies the spark that the engine needs for ignition. So in a situation where they wear out or corrode there would be engine performance issues. Sometimes it would even result in the engine not starting at all.

Apart from the spark plugs, the spark plug wires are also really important. Their duty is to channel the spark created from the coil to the plugs for the ignition.

You can refer to your owner’s manual to know the manufacturer’s recommendations on how to replace them.

Loose Gas Cap

The function of your vehicle’s gas cap is to seal the fuel system. Sealing the fuel system allows the tank to get adequate amount of pressure.

In a situation where the gas cap is not sitting as tight as it should or if it is no more in the best shape or condition, it will result in the pressure of the fuel system being off.

Having a loose gas cap is not too tasking when it comes to fixing it. The options available are quite simple and they are either tightening the gas cap or replacing the damaged one with a new one which is not that expensive.

Failing Mass Air Flow Sensor

The work of the mass air flow sensor is to monitor the amount of air that gets into the engine. It then proceeds to use those findings to regulate the amount of air that should mix in.

What happens when the MAF sensor gets damaged is that your vehicle may no longer be fuel efficient, seeing that the engine is not at optimum performance.

The cost of changing the Mass Air Flow Sensor for most cars is about $100 to $400.

Failing Catalytic Converter

If you have issues with your catalytic converter, it would usually be because you haven’t done your regular maintenance or because you ignored other issues that came up such as issues with the spark plugs, spark wires or oxygen sensor.

This is one of the reasons why it is very important to handle issues with your car as soon as they come up, otherwise it could lead to further complications such as a failing Catalytic Converter.

To change a Catalytic converter will cost you about $1,000. It could even be more than that so to avoid making this expense always go for your scheduled maintenance.

Failing Oxygen Sensor

A lot of vehicles come with four oxygen sensors and when one begins to malfunction it can lead to a drop in fuel economy.

What it would cost you to change your oxygen sensor, is highly dependent on the make and model of your car.

It can be replaced for about $250.

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Fixing It

We will now show you what to do in order to fix a Check Engine Light.

The first step here is to purchase an OBD Reader. This is really good as it allows you to check common engine faults by yourself. You will also be very glad to know that it is not expensive.

If you do not want to have your own OBD Reader then you can go to your local parts store to check the codes.

But if you decided to buy your own and you want to do it yourself then keep reading.

You will have to scan for engine codes using the code reader. To do, first turn off your engine and key. Then look for a trapezoid-shaped port under the driver’s side dashboard and insert the code reader.

After you have plugged in the code reader, proceed to turn on the key to your car but still leave the engine off. You then have to press the scan button and the code will show.

If the code shows up and you do not understand it, simply make a search on the internet regarding it. This is to understand the code and to determine the issue that it is pin pointing.

If you do not find the information that you are looking for online, contact a professional.

So you have been able to identify what the issue is and you are now aware of the engine part to be replaced.

The next thing to do is to purchase the engine part and replace the faulty one.

If you can do this by yourself then carry on, but if you cannot, simply contact a professional to handle it for you.

As you should already know, the cost of repairing various engine parts will not be the same. For instance, replacing a catalytic converter will be much more expensive than replacing a gas cap.

One thing you should always remember is that when you discover an issue, it is best that you fix it right away. Remember the saying that a stitch in time saves nine.

When you have discovered and handled the issue, the next thing that you have to do is to erase the codes. To do this, plug back your reader and press down on the erase button.

However, it is recommended that you re-scan the engine to be sure of the changes. Also you should be able to see that the Check Engine light has gone off.


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