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How to Reset the Check Engine Light (Explained)

Updated: Jan 9

The check engine light, also known as the malfunction indicator lamp (MIL), is a warning light that appears on the dashboard of a vehicle to alert the driver to a potential issue with the engine or emission control system.


If the check engine light is on, it's important to identify and address the underlying problem as soon as possible. However, if the problem has been fixed and the light is still on, you may need to reset it.

 

Table of Contents:


check engine light on a car dashboard

How to Reset the Check Engine Light

Below are the various ways to reset the check engine light.


  • Fixing the underlying problem

  • Switching the ignition on and off

  • Drive the vehicle

  • Disconnect the battery

  • Reset the CEL using an OBD tool


It's important to note that resetting the check engine light without fixing the underlying problem can be dangerous, as it may cause the issue to go undetected and potentially lead to further damage.


If you're unsure of how to diagnose or fix a problem, it's best to take the vehicle to a mechanic for professional help.


Fix the Underlying Problem

The most effective way to reset the check engine light is to fix the underlying problem that caused it to come on in the first place.


This may involve replacing a faulty component, such as a spark plug or oxygen sensor, or repairing a damaged exhaust system.


Once the problem has been resolved, the check engine light should turn off on its own. In some cases it won't clear on its own and needs to be reset, in this case follow the steps below.


Switching the Ignition On and Off

Resetting your vehicles check engine light may be needed. To do this, insert your key into the ignition and turn it on for a couple of seconds, then turn it off for a couple of seconds.


Repeat this process three or four times. This process is similar to rebooting a computer and can help refresh the vehicle's computer system.


If the check engine light remains on after the reset, there may still be an issue with your vehicle or you can try the following steps.


Drive the Vehicle

If you have fixed the underlying causes of the check engine light and there are no issues with the vehicle but it is still appearing, you could try driving the vehicle.


In some cases, simply driving the vehicle for a short distance can reset the check engine light. If the light comes on and then goes off after a few minutes of driving, it's possible that the problem was a temporary glitch or an issue with the sensor itself.


Disconnect the Battery

Another way to reset the check engine light is to disconnect the battery and then reconnect it 15-30 minutes later.


Doing this will reset the ECU and clear the vehicle's computer memory, including any error codes that may have caused the check engine light to come on.


Keep in mind that disconnecting the battery will also erase other settings, such as the clock and radio presets, so you may need to reset them after reconnecting the battery.


Use a Diagnostic Tool

Some vehicles are equipped with a diagnostic port, also known as an OBD port, that allows you to connect a diagnostic tool to the vehicle's computer system.


These tools, which can be purchased or rented (see OBD scanners here), allow you to read and clear error codes, as well as reset the check engine light.


Consult the tool's manual for specific instructions on how to use it and bear in mind the process may be different for every vehicle.

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