How To Reset A Check Engine Light

Is your car's "check engine" light on but you're not sure how to fix or reset it? Here is a super simple guide showing you exactly how to do it.

Many times, the warning lights that illuminate the dashboard are helpful, but other times, they are in the way, providing little to no benefit.

For example, you may have already addressed the issue which caused the check engine light, yet it does not go away.

A few options exist, such as using an OBD-II scanner, reconnecting the battery, and more.

In this article, we will go through multiple ways how to reset a check engine light that should not be there.

It is important to emphasize that you should only reset a check engine light after you have addressed the problem.

Failure to do so may lead to permanent damage which can cost thousands of dollars to fix.

Also, a blinking check engine light signals a very serious problem. It is, therefore, best to avoid driving the car until you are sure that the problem has been solved.

Table of ContentsShow

Diagnose The Problem

car check engine light on

Before you begin to reset the check engine light, you should at the very least diagnose the problem.

In many cases, the cause of the check engine light is not so serious to the extent that you must stop immediately, yet it is important to know the cause.

The easiest way to diagnose a check engine light is to connect it to an OBD-II scanner/reader.

OBD-II stands for On-Board Diagnostic version 2 and is present in every car produced from 1996 till today.

Many years ago, only mechanics had access to an OBD-II scanner or code reader. Today, you can get a simple code reader for only $20 while more advanced ones can cost more than a thousand dollars.

Luckily, in most cases, all you have to do is to buy a cheap OBD-II reader which will show a code that corresponds to the problem in question.

When you are sure why the check engine light turned on, you can proceed to act accordingly by either solving it at once or planning to do it soon if the problem is not very serious.

It is not unusual that several codes come up which may not be related to the check engine light.

Also, if the check engine light turns and then off, the code will still be stored in the memory of the car and you will be able to know why it turned on, even if it was for a split second.

How To Reset The Check Engine Light

Check Engine Light

When you have solved the problem, but the check engine light is still on, there are a few ways to reset and turn off the light.

Use An OBD-II Scanner/Code Reader

One of the best ways and easier ones is to use an OBD-II scanner or code reader.

Just like diagnosing the car, all you have to do is to plug the reader into the OBD-II port and simply press “clear”.

This is the best way to do it as it directly affects the car’s error code memory.

If it turns out that the check engine light disappears for a while to later come back in a short period, the initial problem has not been resolved correctly.

Drive For A While

Driving car

Sometimes the check engine light will show up due to a minor divergent sensor reading or alike.

In those cases, driving the car for a few miles or minutes can make the light disappear itself.

This also applies if you have solved a previous problem but not cleared the code for whatever reason.

This is possible because the car’s ECU “checks itself” regularly in set intervals. In other words, the problem may be solved but the ECU has not been updated yet.

Just make sure that there are no abnormal driving symptoms when driving such as jerking acceleration, noises, bad handling, and more.

Reconnect The Battery

car mechanic replacing car battery VRLA car battery

Disconnecting the battery and leaving it for a while will reset the code memory of the car.

As with every type of work that involves electricity and batteries, make sure to use all precautionary measures and be sure of what you are doing.

There is a simple and good guide on wikiHow, showing you how to disconnect the battery step by step, but also erase error codes with an OBD-II scanner.

Restart The Car

Perhaps the most common answer a customer service agent gives is “Have you tried to turn it off and on again?”.

There is something special with restarting a faulty device, and it may also work with a car.

Some manufacturers have programmed their cars so that old codes reset when turning the car on and off three times.

Simply start the car, let it run for a few seconds, turn off the engine, wait a few seconds, and repeat the process.


The check engine light can be very useful as it may indicate that there is a fault somewhere in the system.

Sometimes the check engine light is nothing but a distraction and turning it off becomes a must.

We have stated it before, but it is very important that you only get rid of the check engine light if you either know that the problem is minor or if you have fixed the problem but did not reset the codes.

There are several ways to reset a check engine light. The most reliable and one of the easiest ways is to use an OBD-II scanner or reader.

If you do not own one, you can buy a cheap one for $20. While a scanner has more functions, a code reader is sufficient.

It is a good investment as it makes it much easier to diagnose any future problem.

A check engine light can disappear itself by simply driving for a while. This is because the ECU updates in regular intervals.

If the ECU checks after a while and notices that there is no problem, the check engine light will simply disappear.

Whenever you drive, make sure that there are no abnormal sounds and that the car drives smoothly.

Disconnecting and reconnecting the battery, as well as turning the car on and off a few times can also reset the check engine light.

Whatever the cause, make sure to resolve any problems as soon as possible and follow the maintenance schedule as specified by the car manufacturer.

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Bajro Muric

Bajro is a big car enthusiast with a love for writing and teaching. He writes about anything regarding cars - from common problems and fixes to racing.