How to Reset a Check Engine Light and Clear Error Codes
This article was co-authored by Jay Safford and by wikiHow staff writer, Eric McClure. Jay Safford is an Automotive Consultant and Project Manager. He is Automotive Service Excellence (ASE), NAFA Fleet Management Association, Ford, and L1 Certified. He has over 15 years of automotive repair experience and has served as an Automotive Instructor at the Lincoln Technical Institute in West Palm Beach, Florida.
There are 8 references cited in this article, which can be found at the bottom of the page.
This article has been fact-checked, ensuring the accuracy of any cited facts and confirming the authority of its sources.
This article has been viewed 1,523,221 times.
Your check engine light typically comes on when there is a problem with your emission control system or another computer-controlled system in your vehicle. [1] X Trustworthy Source Consumer Reports Nonprofit organization dedicated to consumer advocacy and product testing Go to source But if you’ve fixed the problem and it’s still on, you may be scratching your head wondering what’s going on. While something may still be wrong with your vehicle, the odds are very high you just need to reset the light, so breathe easy. In this article, we’ll show you the four ways you can reset it.
Things You Should Know
- Plug an OBD-II scanner into your vehicle’s OBD port and reset it to clear the check engine light.
- Disconnecting and reconnecting your battery will restart your vehicle’s computer and clear the light.
- Drive an older vehicle around for a few days after repairs. The light will go off on its own once the computer resets.
- Turn the ignition to the “on” position 3-5 times and look at your dashboard to spot any error codes or potentially turn off the light.
Method 1 of 3:
Using a Code Scanner
- Note that vehicles made before the 1990s may not have an OBD port under the dash. If they do, it may be an OBD-I port rather than an OBD-II port, so you may need a different scanner. [3] X Research source
- The OBD port has 16 small openings for pins that are lined up in 2 rows. It looks a bit like an old VGA port.
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- The code will be a series of letters and numbers. Record all of the codes so you can figure out what they represent and make the necessary repairs to your vehicle.
- Once the OBD system resets (which occurs after a few drive cycles or a certain number of miles, depending on the vehicle), the light will come back on if the problem has not been fixed.
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Method 2 of 3:
Disconnecting the Battery
- Just FYI, erasing codes by disconnecting your vehicle’s battery can also clear out the memory for your radio and other onboard components.
Drain any remaining electricity from the capacitor. Press and hold the horn for 30 seconds or temporarily switch on the vehicle’s lights. Neither the horn nor the lights will work since there’s no power running to them, but attempting to do so will use up the remaining electricity in the capacitor. [8] X Research source
Wait 15 minutes and reconnect your battery. Leaving the battery disconnected for a few minutes will ensure the vehicle systems will completely reset when you reconnect the battery. Secure the negative cable back to the terminal and cover it with the cap. Disconnecting the battery will clear the error codes and reset the check engine light. [9] X Research source
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Method 3 of 3:
Trying Simple Fixes
- If you don’t drive all that often, now is the perfect time to take that shopping trip where you need to go way out of town!
- The mechanic normally resets the computer codes before returning your car to you, but they may have simply forgotten this time.
- This is most common on older vehicles with more primitive computer systems.
- If the check engine light begins to flash, you have an OBD-I vehicle, which might explain why you’ve had trouble turning the light off. Purchase or borrow and ODB-I scanner to reset the light.
- If a code pops up on your odometer, write it down and look it up online or share it with your mechanic. This is an error code and your check engine light wasn’t on by accident.
See a mechanic if the light continues to stay on. If you still can’t get the light to turn off after resetting the codes, disconnecting the battery, driving it for a while, or turning the ignition, it’s a sign something is actually wrong. Take your vehicle back to the mechanic to investigate what’s going on. [11] X Research source
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How Do You Reset Your Check Engine Light?
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Reputable auto shops will not reset a check engine light without fixing the problem that caused the light to come on.
Consult a mechanic or repair shop if you need help resetting a check engine light or deciphering error codes.
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Use caution when disconnecting and reconnecting the battery.
The emissions monitors in your vehicle will register being reset, so you will not pass emissions if you bring in a car immediately after resetting the codes. Drive your car for at least 200 miles (320 km) before bringing it in for an emissions test.
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References
- ↑https://www.consumerreports.org/cars/car-repair-maintenance/what-does-check-engine-light-mean-a2041364753/
- ↑https://www.digitaltrends.com/cars/everything-you-need-to-know-about-obd-obdii/
- ↑https://www.bumper.co/blog/what-is-an-obd-port
- ↑https://www.digitaltrends.com/cars/everything-you-need-to-know-about-obd-obdii/
- ↑https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing
- ↑https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing
- ↑https://www.caranddriver.com/features/a26873586/car-battery-disconnecting/
- ↑https://www.motortrend.com/how-to/1804-repairing-electrical-problems-by-draining-storage-voltage
- ↑https://mechanicbase.com/engine/will-my-check-engine-light-reset-itself/
- ↑https://www.boston.com/cars/car-guides/2020/02/04/how-driving-can-reset-the-check-engine-light/
- ↑https://www.boston.com/cars/car-guides/2020/02/04/how-driving-can-reset-the-check-engine-light/
About This Article
Co-authored by:
Master Mechanic
This article was co-authored by Jay Safford and by wikiHow staff writer, Eric McClure. Jay Safford is an Automotive Consultant and Project Manager. He is Automotive Service Excellence (ASE), NAFA Fleet Management Association, Ford, and L1 Certified. He has over 15 years of automotive repair experience and has served as an Automotive Instructor at the Lincoln Technical Institute in West Palm Beach, Florida. This article has been viewed 1,523,221 times.
69 votes – 86%
Co-authors: 20
Updated: July 17, 2025
Views: 1,523,221
Categories: Car Engines
Sometimes your check engine light won’t turn off even after you’ve fixed the problem with your vehicle. When that happens, you’ll need to manually reset the light. One option is to turn the ignition on and off 3 times in a row. Then, drive your vehicle around and check to see if the light goes off. If that doesn’t work, turn off your car, pop the hood, and disconnect the positive and negative cables from the battery. Press on the horn for 30 seconds to drain any remaining electricity, then wait 15 minutes before reconnecting the battery cables. Disconnecting the battery like this may reset your car’s electrical system and erase the error code that’s causing the check engine light to stay on. If all else fails, purchase an OBD code scanner and plug it into the OBD port on your vehicle, which should be located under the steering column. Turn on the scanner and wait for it to scan your vehicle for error codes. When it’s finished, you can erase the error codes that appear on the scanner, which will turn your check engine light off. To learn how to reset a check engine light with a code scanner, read on!
How to Reset A Check Engine Light in 5 Simple Steps
Once the Check Engine Light shows up, you know there’s something you must address. The onboard diagnostics (OBD) system analyzes the various car components to ensure everything is working right. If there’s a fault, you will see the warning message appear on your dashboard or information display. That’s when you need to know how to reset the Check Engine Light.
In this guide, we give you some suggestions and discuss why it’s important to fix the underlying problem first. We also touch on what to do if the engine light comes back on and give you some answers to questions that have been bothering you.
If you still don’t want to invest in a code scanner, there are plenty of auto parts stores that offer free car diagnostics and will tell you what faults are present. You could also visit a local mechanic and get the codes scanned, although there will be a service charge for this work. Whenever the Check Engine Light is on, it means that there’s a fault read by the computer. You want to get to the bottom of what’s causing it to avoid further damage. Some trouble codes are easy to understand and fix, while others can be much more complicated. That’s why we always recommend using our free online trouble code library when you attempt to fix your vehicle.
Can you reset the Check Engine Light without a scanner?
Yes, but the scanner provides the easiest way of dealing with the Check Engine Light. If you don’t have one, you may be able to disconnect the battery, pull a fuse, run through an ignition cycle or try to drive the vehicle for a few days. However, these methods only work once you’ve repaired what caused the code in the first place.
How long does it take for a check engine light to reset itself?
It depends on the type of vehicle you drive. With some cars, it can take anywhere from 10 to 100 miles of driving before the light resets on its own. The engine computer needs to perform a check on the system that was malfunctioning and notice that it is running normally now. Some systems are checked constantly, while others only have a check occasionally.
Do you have to drive to clear a check engine light?
No, there are other ways to clear the Check Engine Light without driving. If you have a compatible code scanner, you can easily reset the system without going anywhere. Otherwise, you may be able to pull a fuse, cycle the ignition or disconnect the battery for a short time.
How do you reset the check engine light on the gas pedal?
Some vehicles have a reset procedure that involves cycling the ignition and pressing on the gas pedal. To find this method, you want to read the process in your factory service manual. Otherwise, you would be wasting your time trying a process that may not work for your type of vehicle.
Will AutoZone reset the check engine light?
It depends. Many AutoZone locations provide free diagnostics with a compatible code scanner. They will tell you what codes are present and offer some potential fixes to help you save money. However, not all locations will reset the check engine light due to liability reasons. It’s still worth a try if you don’t have a code scanner.
Is a check engine light an easy fix?
It depends on what caused it to come on in the first place. If the gas cap is too loose or damaged, that would be an easy fix. On the other hand, trouble with a lean or rich system can be difficult to troubleshoot. There are also some warnings that lead to expensive repairs, such as when the vehicle needs a new catalytic converter.
After you’ve repaired the fault associated with the diagnostic trouble codes in the computer, it’s time to reset the Check Engine Light. You have several methods for doing this, with the easiest option relying on the code scanner. However, not everyone has a code scanner, so this method isn’t always possible.
With some trial and error, you may be able to find another way to turn off your car’s Check Engine Light. Whether you choose to disconnect the battery temporarily, pull a fuse, cycle the ignition or just keep driving, you may find relief from this annoying warning light. If you can’t get it to turn off, the problem may not be fixed or you may need to visit a professional mechanic.
Sources
- How to Reset Tire Pressure Light (TPMS) – By Car Model
- How to Reset Airbag Light? (5 Steps) With or Without Scanner
- How to Reset a Throttle Position Sensor (7 Methods)
https://www.wikihow.com/Reset-a-Check-Engine-Light
https://mechanicbase.com/engine/how-to-reset-check-engine-light/
