Kate is a research enthusiast with a Bachelor of Science degree from Sonoma State University. Kate has a passion for the automotive field.
Why Is My "Check Engine" Light On?
You've fixed the issue that made your "check engine" light turn on, but now it won't turn off! This may not be your fault. Sometimes the computer in your vehicle will need a little help to see that the issue has been resolved. I'll go over a few techniques for resetting your check engine light.
This light displays itself when the onboard computer system recognizes an electrical or mechanical problem with your vehicle. When the problem is fixed, the engine light does not always turn off. This can be annoying, cause you to fail an emissions (smog) test, or keep you from finding out about future problems the vehicle's computer might be trying to alert you to.
Of course, it is essential to be sure that the light isn't on because your engine really does still have a problem. Try one (or more) of the following approaches to turn the light off. If it does not go off, then your engine has a problem.
4 Ways to Reset the "Check Engine" Light
1. Drive your car and let light go off by itself.
2. Turn the engine on and off three times in a row.
3. Disconnect and reconnect the battery.
4. Use an OBD code reader.
Wrench and OBD reader
1. Drive Your Car and Let the Light Go Off by Itself
The first and easiest method for clearing the check engine light is driving and time. Most onboard computers will recheck whatever problem caused the check engine light to activate multiple times. Drive your car as you normally would.
If the check engine light is still on after three days, your problem may not have been fixed or you may need to try some of the methods below to reset it.
2. Turn the Car On and Off Three Times
Some vehicles will automatically reset the trouble codes that caused the initial error after the vehicle is turned on and off three times in succession. To do this, insert your key into the ignition, turn the vehicle on for about a second, and then off for about a second. Repeat this two more times then drive the car as normal. Check to see if the check engine light reset.
3. Disconnect and Reconnect the Battery
You will need a wrench. Prop open the hood and use the wrench to disconnect the positive power cable to the vehicle battery. Leave the battery disconnected for at least 15 minutes. Then put your key into the ignition and turn it three times to the “ON” position. This will clear the emissions data from the vehicle memory as well as the readiness flag data.
Reconnect the positive battery cable and turn the key in the vehicle ignition. Wait one minute and the check engine light error should be gone.
4. Use an OBD Code Reader
You will need a wrench and an OBD (onboard diagnostic) reader. These inexpensive readers analyze and clear engine codes. I have used the Kobra OBD scanner with great success many times for this task.
To perform this method:
- Plug the reader into the OBD port of your vehicle. This port is usually located on the underside of the dash area just above the foot well. On some vehicles, you'll have to remove the door on your fuse box to access this port.
- Once you have connected the reader, press the "enter" button to turn it on.
- The device will scan your engine for any error codes. Once done analyzing, the reader will display any error codes it finds. Make note of the codes (if any) if you wish to cross check them in the code reader's manual or online.
- Now you can press the "scroll" button to find the option to erase the code. Press enter while on this option to erase the fault code and reset the check engine light.
Frequently Asked Questions
Here are just a handful of commonly asked questions related to this issue.
Can the check engine light turn off by itself?
Yes, sometimes the light will turn off by itself as you drive it around for a while after addressing the issue that made it turn on in the first place.
Why does my check engine light turn on and off intermittently?
There could be a few reasons why this is happening. A loose gas cap, failing engine sensors, bad spark plugs, faulty valves such as in the EGR (exhaust gas recirculation) system, or intermittent misfiring could all be potential culprits. In this case, it's often best to take your car into a mechanic shop to get a diagnostic, or at the very least use an OBD reader yourself.
Does the check engine light turn off automatically after repair?
Sometimes yes and other times no. If the issue has been repaired and the computer has been cleared with a scan tool or code reader, then the light show turn off relatively soon after.
That's not always the case though, and the light may still stay on (or turn on and off intermittently)—especially if you have a larger electrical or wiring problem.
If you got your car repaired at a mechanic shop and the issue seems to be resolved but the light remains on, however, then you should take it back to the shop and ask the mechanic if they can reset the light.
Do I need a special tool to turn off my check engine light?
Yes. If you want to turn off your check engine light yourself, then you will need an OBD code reader. It plugs into the diagnostic port commonly located under the dashboard in cars made in 1996 or after. These devices can be purchased at various automotive parts stores or online at various retailers such as Amazon.
Be advised, however, that if you use an OBD reader to clear the code but the issue has not actually been resolved, then the check engine light will likely turn back on again sometime soon thereafter.
These Techniques Should Help You Reset Your Check Engine Light
Following these techniques will allow you to rid the annoying check engine light as well as allow for new problems to be displayed properly.
Whether you choose to manually reset the onboard computer by resetting the battery or by using an OBD reader, you will be able to successfully fix the error. You may use these techniques to fix the check engine light error as well as any other errors in the future should they present themselves.
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.
Questions & Answers
Question: Can I get rid of the "check engine" light without an onboard diagnostic reader?
Answer: You certainly can, but it may be more difficult. I would start by trying the other methods outlined in this article. If those don't work, then there is likely something mechanically wrong with the vehicle.
It can be as simple as replacing an easy to reach $10 sensor that has gone bad, or much more difficult. While some expert mechanics can troubleshoot their vehicle and locate the issue without the assistance of an OBD reader, most people (such as myself) need a code reader to make things easier for us.
A code reader can help you by manually allowing you to clear the fault code that has caused the check engine light to illuminate (in case it was stuck on due to an error in the car's computer), or if there truly is something mechanically wrong then it can give you the "error code" that your car is producing.
This error code is the actual reason the check engine light has been activated. You can then look up this error code in the reader's manual or online and see what the issue is with your vehicle in plain English. It is a handy tool that even most expert mechanics quite heavily rely on these days.
Question: Why did my check engine light come on after I replaced some fuses?
Answer: Likely one of these situations occurred:
1. You replaced a fuse with a fuse of an incorrect value. Double check that you used the correct type of fuse per the vehicle's manual.
2. One of the fuses you inserted is bad or quickly went bad after installation, causing one of the systems in your vehicle to stop working correctly.
3. You replaced a bad fuse, causing a system in your vehicle that was not working previously to start working. That system has an issue causing your vehicle to display the check engine light. This is less likely if the check engine light wasn't on before this.
4. It's a coincidence and another system in your car started to experience an issue just after you replaced the fuse. Believe it or not, this does happen even though it is also less likely.
The easiest way to narrow down the problem is to use an OBD 2 reader, such as the one I linked to in the article, to read the trouble codes from your car's computer. You can then cross reference this code online or with the manual that comes with the reader to find out exactly which system is causing your car's check engine light to illuminate.
Question: I replaced my vehicle's O2 sensor, disconnected and reconnected the battery multiple times, and even changed its plugs, yet the check engine light came back on after a 45 km drive. What should I do next?
Answer: If your car is 1996 or newer model, you should connect its computer to an OBD2 reader to find out what error code it's generating.
Once you get this code, you'll be able to translate it and gain a better understanding of what is wrong with your vehicle.
If it says it is "out of range," which is very common when a sensor malfunctions, replace the faulty sensor. Then take the steps outlined in this article to reset the check engine light.
© 2012 Kate Daily
Joseph Mwai on June 27, 2020:
My Honda Sendan sport,check engine light is on from today,the service is on 7/6/2020,i checked the engine oil and it was low the second mark,so i thought thats itand i added some oil,but the check engine light hadn't been off yet
Shailesh on June 25, 2020:
The problem is this - once you reset the light either by using a scanner or disconnecting the battery, the obd monitotrs get reset and show as incomplete. While all the monitors show ready after driving the car a few miles, the catalyst monitor does not. When it does become ready, the light is back on. So I cannot get the car to pass the smog test. Thoughts? I have a 2000 Honda CR-V.
Bethany H on June 19, 2020:
I tried #3 on my 2007 Nissan xterra. It worked like a charm. Thank you!!
Jerry Abbott on June 12, 2020:
My Sister had a Lincoln her light came On--they knowed this ford Manchinic --good friends --He came out and fixed the Problem---He told her--give me about 20 minute and Your Check Engine light will never come on again --and Your Car will pass Inspection --Your On Board Computer will not Relize the check engine light is On and it won't show on The Dash Board---==she drove about 5 more years and it never came on again--and it Passed inspection every Year after that what did He Do
Fred Reed on June 07, 2020:
I have a 2007 Chrysler PT Cruiser which the code reader indicating P0700 as default to the transmission what would be the solution to this problem
Holly on May 29, 2020:
I have a 2014 Dodge Charger. The two fuel pumps were replaced. Engine light is on. When checked it says it's the fuel pumps but they've been replaced and car runs. Help please.
Mike on March 05, 2020:
My toyota obd has no power,all fuses are ok.what the H is wrong? I have tuck battery connect off,but three dsys its back on.
George Sinese on February 24, 2020:
Thank you, Kate,,,,, very helpful !
Genine on February 23, 2020:
My check engine light came on and it showed that it was the thermostat. I had it fixed and the light is still on my 2010 nissan altima. I have a push start button.
Jim Stiver on January 26, 2020:
I tried #3 and it worked on my 2012 Dodge Caravan...Thanks...Jim
Sandra on January 26, 2020:
Do you reconnect the battery vable then turn the key to on position 3 times or befor you reconnect
Rick on January 18, 2020:
I removed active shutter grill. Do you recommend a scanner that can disable code, po59f. I can clear it, need to disable.
TonyB47 on January 11, 2020:
I replaced both etc sensors and engine still runs sluggish after warm up and eats alot of gas. It is a 98 suberban. What else could it be?
DANIEL HAYES on January 09, 2020:
Have a 2010 Ford Explorer,have 7 codes all pertaining to emissions, like o2 sensor , egr valve , map sensor etc... changed all parts but still having check engine still on ?? And car shuts off when stopped at light or when a lot of stop & go traffic
hector on October 21, 2019:
a 2001 toyota corolla the check engine light is on. i erase it and i can drive it as much as i want to and it won't turn on until i turn off the car and turn it back on in a few minutes the light turns on.
Thabana on October 16, 2019:
I want to find out what the problem might be if my vehicle check engine light turns it self on and off. the light turned it self on Friday and I plugged in my obd2 scanner which gave me trouble codes P0101 and P0420 and I was planning to take it to the mechanic on the next Friday and now it Wednesday afternoon, when I check the light is off by it self and without having addressed the problem.
Mike on September 17, 2019:
I have a Ford Focus SE 2007. I just had a auto mechanic just replace the fuse for my dash. And the minute I turned the engine over. When I got it back. The check engine light came on. I know everything checks out fine. Example: the OD I code is reset. I had the engine fixed so it can pass The smog. They even gave it a full diagnostic. The first time around. Gave it a lube and oil change. Found out it was a valve stuck open for emissions system. Can I still drive?. My mom says she going out of the country on the 18th of this month. Sorry, I don’t sleep well when a check engine light is on.
Atiq on July 29, 2019:
I hv got honda accord 2003, check engine light is on. I checked with code reader it gave me knock sensor error. I replaced the knock sensor but the check engine light is still on. What shall i do?
Jamesw Vander Putten on July 07, 2019:
Three times off/on on my 2008 Bmw worked
firstname.lastname@example.org on July 03, 2019:
2007 honda civic si 2.0 liter ..ok my story goes like this my second fan was not working ,so my air conditioning was warm and cold . so while my engine was running I decided to pull my relays out all sudden I pulled this relay and the car sounded like it had a hole in muffler like it lost power so I get in it and all these lights came on put the relay back in and shut it off , so all lights when of and the check engine light was still on.got my obd machine erased check engine light ..light didi not come back on after driving it . but on the fifth day went back with the obd reader and it has a yellow light..instead of a green . code reads as follows p1659 and it says #1tacm relay stuck off #2etcs control relay malfunction .. car runs great but please help me I have to get this car inspected . and there was nothing wrong with this car until I pulled that relay out while my engine was running .
Valentino olape on June 21, 2019:
My 2000 volvo v40 how to restore i deleted the engine light on& code.
Clifford on June 04, 2019:
My ford focus ecoboost shows the yellow engine light but just gone to a service. Ho should I reset it. It make some funny sound on the desh board don't know if it have a faulty
Bianca on May 20, 2019:
I have a 2005 acura tl just got out of the shop for a transmission rubuild and now check engine light is on reading a code of p0741
Andy Rodeheaver on May 04, 2019:
how to get rid of engine light, had checked they said to google this number P0743
Eugene M Gershunov on May 02, 2019:
I cannot pass the smog check because the secondary air injection ports are plugged with carbon deposits. What do you recommend to do to clean the ports without bringing the car to a machine shop? That is very expensive. I turned off the check-engine light and followed your recommendations from "Tips and tricks ...". and burned 2 tanks of gas (more than 500 miles) but the AIR check on OBD is still red. Please help.
Kate Daily (author) from California on March 23, 2019:
I would start by contacting the garage (or looking at your paperwork) and getting make and part number of the alternator and starter they installed. Then double check that those items are compatible with your car. I have never heard of a starter causing the light but the wrong alternator sure can!
louise sara mc menamin on March 23, 2019:
i had my car in the garage and got the starter and alternator replaced...once i put diesel in the engine, the engine management light came on..obviously i know theres nothing wrong with the car..how do i get this off...Ford Focus 2010
Al Ong on March 03, 2019:
I tried to turn the Car on and off Three Times but the check engine light won't go away. My car is Honda Odyssey (2011), is the method (method 2 per instruction) working on Honda Odyssey?
faraz on January 17, 2019:
swift 2015 how to check engine light remove sometime indicate
Seanbike on December 04, 2018:
Felipe Beltran on November 14, 2018:
This information has been very helpfull. Thanks
Debbie Pemental on October 22, 2018:
If disconnect my battery and reconnect it and the engine light goes off will it pass inspection
Lee on August 04, 2018:
As for step 2 above: Do you actually have to start the car for a second, then turn off for 1 second - 3 times, OR do you just turn the ignition key to the ON position for 1 second then back to the OFF position for 1 second - 3 times.? Thanks a lot. I am having this problem for 5 years now, and replacing the same item O2 Sensor, each year, I have to show proof of a $200,- repair bill each year just to be able to get a Emissions waiver from the State Police to be allowed to renew my tags in my county in the state of NC. It is a hassle.
James wilson on July 28, 2018:
My bmw 320i has a fault code reading nox sensor heating ican put it off with my disgnostic machine and drive for miles but when i stop the car and start to drive again it comes back on please help
Joel on June 26, 2018:
Hello, my 2009 A4 engine light continues to come on. My mechanic has reviewed it and ran tests on it and cannot find anything wrong with my car, even though the engine light is on. Any suggestions on what to do or maybe what it might be?
Theo on May 17, 2018:
Google the OBD code, there all in there !
waylon on April 17, 2018:
I have a 97 audi a4 1.8t and the check engine oil level andcheck engine light is on and it won't shift in reverse or drive how do I fix it
Kate Daily (author) from California on January 08, 2018:
No, problem! Good luck, let us know how it goes!
bryan on January 07, 2018:
Thanks a lot Kate...i now have an idea of how to get rid of my problem!... for my Ford Focus 2008 model!
Adrian F. Good on December 26, 2017:
Credible suggestions. I'll try the first three and if they don't fix it, I'll take it to my auto mechanic and ask him to use his OBD code reader. What a pain in the neck it is to install a new battery in a late model car. Thanks for your advice, Kate Daily.
Kate Daily (author) from California on December 12, 2017:
A loose or damaged gas cap is actually a pretty common reason that a check engine light will come on. Your car's computer probably just needed a little help after you fixed the issue. You did the right thing!
Yes, as long as your check engine light stays off throughout the smog test, you should be fine. Take a look at my other article (below) which may be helpful to make certain your car passes smog. Good luck!
Penny Lister on December 11, 2017:
my check engine light was staying on so I replaced the gas cap, but the light was still on, so I took the ground cable loose from my battery, pressed the horn for 30 seconds, and i waited for 15 minutes to reconnect the cable to the battery. Once i did that, my check engine light is now off. I have driven the car approximately 30 miles since then and it is still off. Do you think I have fixed the problem and do you think i can now pass emmissions?
Kate Daily (author) from California on December 07, 2017:
There could only be a few reasons why the check engine light would remain. These are in order from the most likely cause to the least likely:
Possibility 1 - The problem that caused the computer's error code (which is making the check engine light illuminate) was not fully fixed. Even if you replaced the sensor, it may not have truly been a faulty sensor that is the issue. It may have been what that sensor is detecting (i.e. a bigger issue with the engine).
Possibility 2 - There is an issue with the connection to the sensor. I know you checked for loose connections, but did you check the wiring from the computer to the sensor itself? Try doing this by using an ohm meter to get a reading on the resistance across just the sensor, then connect the sensor and find the same sensor wires back at the car's computer. Test the resistance between those two wires back at the car's computer. They should be just about the same resistance. If the resistance is significantly higher or lower than what the resistance was across just the sensor by itself, then you have an issue with the wiring and/or connection to the sensor.
Possibility 3 - The car's computer is faulty, this is by far the least common. See items 1 and 2 above first.
I hope this gives you a good starting point. If you would like, post what specific error code your car's computer is giving you (read the codes with the OBD 2 reader) and I can give you more ideas on where to look.
Rick dreves on December 07, 2017:
What if you've done all these procedures and your check engine light is still on replaced all O2 sensors map sensor check for all loose connections and a good ground but the engine light still on and still gives the same code that you just repaired
Kate Daily (author) from California on October 08, 2017:
Hi Paul, I would definitely start by canceling the fault code to see if the code comes back. If it does then it may not have been the sensor itself that's the problem, rather it may be what the sensor is detecting. Here are some thoughts that may be helpful:
1 - Check for loose or corroded electrical connections in the wiring harness near the sensor.
2 - Are there any other electrical related issues with the car? If so they could be related (like a loose or corroded grounding wire).
3 - Check the vacuum system (i.e. vacuum hoses and connectors) for any lose or brittle/broken parts. If you have a small vacuum hose with a crack in it, it could cause your fault. Try using a vacuum gauge for chasing down any issues with the vacuum system.
Hopefully you find some of this useful for fixing your problem!
Paul Luckhurst on October 08, 2017:
Had no acceleration,fault code P0105 map sensor. I have replaced the Sensor,but still have acceleration problem (but not as bad) ? If i cancel fault code, will it clear, and reset engine back to normal operating mode
Krissy chestnut on April 19, 2017:
I have a 2005 Chevy Cobalt and my check engine light came on . So I hooked the scanner up to my car and it said for me to reset the check engine light. So I did and a few days later the check engine light came back on and it's still saying I need to reset the check engine light. Also the light goes off and then will come back on. PLease help!!! I'm at my wits end.
betty graske on April 11, 2017:
I have a 2001 toyota highlander and the engine light was on. I took it to my mechanic and he said he repaired the problem. Went down the road 2 miles and it came back on. Took it back to him and 3 days later he said it was done. Went down the road and the gas gauge was not working. Took it back again and he said the wire broke off. I have reason to believe he disconnected my engine check light. How do i have that checked without spending more money.
Levi on January 28, 2017:
Good day i have a mitsubishi lancer 4g92. I went to two different diagnostic. Both told me their scanner isnt picking up any problems. The car cranks but wont turn over. I changed plugs but im not getting any spark. I changed cam and crank sensor. None of this has worked. The check light is coming on as usual then it will go off as usual. Even with the engine light on im still not getting any reading. What is this problem i am facing? Help.
joeblevins on December 31, 2016:
Wow...unbelievable...after fixxing the oxygen sensor on my Ford Explorer XLS to get it to pass the emissions test the check engine light turned bk. On...couldnt believe it, so I thought i probably had to return to the shop for further examination but thanx to this website i followed the easy steps to reset it myself... And sure enough i unplugged the pos. Cable as described and follow the remaining steps before reattaching the cable bk on and to my amaze it WORKED!!!!... WooHoo!!!!!!....Thanx for the useful info to help solve the problem...2 THUMBS UP!!!!!!!!....
joeblevins on December 31, 2016:
Wow I cant believe after i got my oxgyen sensor fixed on my 2001 Ford Explorer XLS came bk on after having it fixed to pass Illinois Emission Test that this info i read on line wit u guys worked 100% plus ...I followed all steps provided and the one that eliminated the check engine light was unplug the pos. battery terminal and inserting the key before re-attaching the cable bk... I thought i would have to take it bk to the shop for further examination But dont need too...Thanx for the info. On how to reset the problem myself...2 thumbs up for this website....
Evans on November 25, 2016:
I followed the manual technique the light off momentarily and then came back on! Mine is a 2009 mazda bongo van. The irritating light is still on.
Stephanie on October 09, 2016:
I reseted my engine light but now before I foolly turn on the car it still turns on
BIG ED!!! on September 03, 2016:
Wooohooo. Left my dome light on, which killed the battery in my Subaru Forester. Turned the car on multiple times as indicated above and it reset the check engine light, hill descent and traction control lights and the car is back to normal. Thanks
John on August 13, 2016:
Thanks so much!! I found other sites that advised to disconnect the battery, but yours was the only one that advised to put the car in the "on" position 3 times before connecting the battery again. This seems to have done the trick. The light is no longer on.
ben thuku on August 05, 2016:
my prando check engine shows when the car inclines .
what is the problem?
Your Name on November 28, 2015:
help my toyota probox,,when i drive 5okms,the engine gets really hot and all over sudden it switches off while on motion.when cool it takes off for a short distance and then showing check engine then it goes off!whats the issue?
felicia on April 22, 2015:
Help, my Honda fit 2007 is acting up! When I was driving on the highway yesterday the engine light turn on , also while accelarating the car was not speeding up to par. I went to take it to auto zone and they did a diagnostic test little machine that looks like a phone and it said that the oil pressure was low etc etc. What does that mean. I checked my motor oil and its fine. Is it expensive to fix? Please help me.
Ana Maria Orantes from Miami Florida on April 08, 2014:
Thank you for the information Mr. Wolfy. It is true about what you are saying. I had the same problem with the light. And some one did all that work. The light is no longer on.