Informational Guide

How To Reset The 'Check Engine; Light

You don’t need to visit the mechanic to find out why the Check Engine Light is on. You can do it from your home garage with these simple steps.

It’s everyone’s worst nightmare. You are driving down the road and the Check Engine Light comes on. You do the responsible thing and fix the problem, but do you know how to reset the check engine light?

We evaluate the steps, showing you how to reset your check engine light in a variety of situations.

The Check Engine Light is a warning to you that something within the car’s systems is wrong. This generic message can mean a number of issues, including:

  • Engine trouble
  • Transmission problems
  • Imbalanced emissions
  • Air/fuel delivery trouble
  • Failing modules or sensors
  • Ignition system failure

When the Check Engine Light comes on and stays on, you could have a minor or more severe problem. It could be as simple as the gas cap not being secured to something major, such as engine trouble.

However, the flashing Check Engine Light is much more serious. This indicates that there is a critical fault, and you should stop driving immediately.

How To Reset Check Engine Light

How To Diagnose Your Car’s Check Engine Light (Understanding The Codes)

You don’t need to visit the mechanic to find out why the Check Engine Light is on. You can do it from your home garage with these simple steps.

  1. 1
    Purchase an OBD-II scanner.
  2. 2
    Find the diagnostic port, usually located below the steering wheel.
  3. 3
    Plug the scanner into the port and read the codes.
  4. 4
    Perform online research to figure out what the fault codes mean.

Here are a few of the most common diagnostic codes.

  • P0128 – Coolant Thermostat
  • P0171/P0174 – System too Lean
  • P0300 – Cylinder Misfire Detected
  • P0420 – Catalyst System Efficiency
  • P0442 – Evaporative Emission System Leak

For the most part, you can diagnose almost any code from a vehicle dating back to 1996 models and newer. Here is how the majority of codes are broken down, although there are some exceptions.

1st Digit: B stands for Body, C stands for Chassis, P stands for Powertrain, and U stands for Network

2nd Digit: 0 is a generic code, while 1 stands for a manufacturer-specific

3rd Digit: Different meanings based on the number.

  • 1 – Fuel and Air Metering
  • 2 – Fuel and Air Metering Injector Circuit
  • 3 – Ignition System
  • 4 – Auxiliary Emissions Controls
  • 5 – Vehicle Speed Controls or Idle Control
  • 6 – Computer Output Circuit
  • 7 – Transmission

*4th & 5th Digit: This is your specific fault code, ranging from 0-99

How Do You Reset A Check Engine Light?

You have several different options when you are asking - how to reset my check engine light? To start, you could consider driving. Once the repair has been made, the computer might recognize the change on its own. This is the best way to learn how to reset the check engine light without a scanner.

So, let’s say that you get an error for the check engine light gas cap. How long to reset can you expect? It shouldn’t take more than three days for the error to go away on its own.

However, there are ways to deal with the fault quicker. You can also attempt to start and turn off the car three times. This is a great method if you want to know how to reset the check engine light without disconnecting the battery.

However, if you are able to disconnect the car battery, you provide a hard reset to the ECM, which should wipe out any codes. While the battery is disconnected, wait about 15 minutes before hooking everything back up again.

Depending on what OBD II scanner you purchased, you might also be able to use this tool to clear DTCs. Of course, the majority of cheap scanners won’t offer this option. While many auto parts stores will read the codes, the employees will not use the scanners to clear codes. You will need to have your own machine to perform this task.

If you clear the code and the Check Engine Light comes back on, you have larger issues. If you cannot fix what’s wrong with the vehicle, you will need to visit your local mechanic. Not only will they repair the vehicle, but they can also clear the code and reset the Check Engine Light.

How To Reset Check Engine Light Without Scanner

People Also Ask (FAQs)

How can you reset the check engine light on a Chevy Silverado?

If you want to know how to reset a check engine light on a Chevy Silverado, simply turn the ignition on and off three times. This should reset the system.

How can I reset the check engine light on a Toyota (Camry and Corolla)?

Learning how to reset a check engine light on Toyota Camry cars would be the same as figuring out how to reset a check engine light on Toyota models in general. The most effective way is to disconnect the battery for 15 minutes.

Is it safe to drive with the check engine light on?

When the Check Engine Light comes on, you should figure out the issue promptly, but it could be something that’s not serious, such as a loose gas cap. However, if the Check Engine Light is flashing, there is a critical error that requires immediate attention. Stop driving the vehicle and have it towed.

Will the check engine light reset itself?

The Check Engine Light can reset itself, but most people don’t like to wait. In total, it could take up to three days for the system to recognize that the problem has been fixed.

Why is my check engine light off, but the code still there?

Let’s say you’ve fixed a misfire, but the code is still in the system. If the Check Engine Light has gone off, but the code remains, you haven't cleared the code from the system. Use your scanner to erase the code that would otherwise be stored in the system.

Can you disconnect your check engine light?

You can remove the lamp from the Check Engine Light so it doesn’t show up. However, you won’t ever know if there is a problem that needs to be dealt with.


Learning how to reset the Check Engine Light on your vehicle isn’t complicated. There are several methods that will work; you just have to choose the most convenient option for you.