Check Engine Light Turned Off By Itself: Is It Okay? (Explained)

Once in a while, your engine light will turn on because of some technical failure. But let us talk about your check engine light turning off by itself and if it is okay. Let us start. 

So is it okay to have your check engine light turned off by itself? The answer is yes. If a car system fails a test, it will turn on the check engine light.

It would take two failures for the light to be turned on. So after the vehicle fails to pass the three tests, it will take forty passes for the light to turn itself off. This is one of the worst things about owning a vehicle. 

You might be driving down the street, and then suddenly, your check engine light is turned on. You might panic, and you are already thinking of the expense of fixing your vehicle. But before your overthinking gets worse, your check engine light shuts off. 

And there are times when the engine light will start to turn on again, and then you have this intermittent engine light that is turning on and off. It is very frustrating for vehicle owners. 

So let us discuss if it is okay for the check engine light to turn off by itself. Continue reading to learn more.

Check Engine Light Turned Off By Itself

Can Check Engine Light Turn Itself Off?

The reason that the check engine light is turning off is that the vehicle has failed some tests. For example, it might be a continuous monitor like an engine timing or misfires or a non-continuous monitor like the catalyst, the EVAP system, or the air-fuel ratio. So it has all these tests, and when they see a problem, it will fail the test. 

Why Check Engine Light Came On Then Went Off?

If your check engine light is on and off intermittently, you must not have to worry. However, these engines will keep your check engine light turned on for an extended period. So here are the reasons why your check engine light came on and went off.

You Might Have A Loose Gas Cap

A loose gas cap can cause the check engine light on and off. If you don’t tighten your gas cap, it can cause a check engine light to come on. You then have to tighten your gas cap if this is the problem. 

You Might Have A Faulty Oxygen Sensor

If a loose gas cap does not cause your intermittent on and off check engine light, it can be because of a faulty oxygen sensor. The oxygen sensor in your vehicle is in charge of ensuring that your engine will have the right amount of oxygen. The oxygen is mixed with the gasoline in your vehicle to keep your vehicle going. 

If there is not enough oxygen, then the combustion process will not play out like it is supposed to. If there’s too much oxygen, then it can lead to damage to your engine. That is why your oxygen sensor needs to help provide the right mix. If the oxygen sensor is not working correctly, this will turn your engine off and lead to your check engine light turning on. 

You Might Have Bad Spark Plugs

It can be because of a bad spark plug. A worn-out spark plug can affect the combustion process of your engine. 

This can make your check engine light activate and off intermittently. You can continue to drive with it, but they will worsen over time. 

You Might Have A Faulty Mass Airflow Sensor

If you are driving, the air from outside will pass through your air filter. This will then make its way towards the engine. This is called the mass airflow sensor. 

It will measure how much air is getting into your engine. This is made to prevent a lot of air or not enough air from reaching the engine.

If it goes wrong, this can cause a reduced fuel economy and lead to a check engine light on and off intermittently. Therefore, you must not ignore this problem. 

What To Do When The Engine Light Turns Itself Off?

It is okay for your engine light to turn itself off. However, you still need to have your vehicle checked. It would help if you made sure that there were no other issues.

Check Engine Light Turns Off After Starting The Car: Is It Okay?

Every car will light up all the dash lights before they start. This is to check if the lightbulbs are good. Most of the check engine light turns off a fraction of a second if the engine starts. 

Check Engine Light Went Off After A Week: Is It Okay?

You will experience an intermittent on and off check engine light. This is because the ECM can detect a problem like the variable valve control system o a small EVAP leak like a gas cap. And this must be addressed. 

Even though the codes are not yet complex, the light will continue to blink if it goes out completely. To be sure, you have to consult an expert to have your vehicle fixed.

Check Engine Light Comes On And Off With No Codes: Is It Okay?

Some codes create an error. For example, one standard error is the fuel filler cap. This is because the engine will go through a systematic procedure of sensing pressure in the fuel system in determining the need for an emission canister. 


In summary, a check engine light can make a car driver panic because it means something is wrong with your vehicle. But there are times when your check engine light will turn off by itself. 

The check engine light will turn off by itself. If you want to be sure and safe, have your vehicle checked.

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Image credits – Canva

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My name is Hank, and I've been in the automotive industry for 27 years. I've been working in my own auto repair shop for the last 13 years, and now I want to help you here, on my blog. Let me know if you have any questions. Read more