How to Reset Check Engine Light: A Complete Guide

OBD2 Scanners is reader-supported. When you buy through links on our site, we may earn an affiliate commission.

how to reset CEL

The check engine light warning on your dashboard may cause you to panic, especially that there is no way you can know what's wrong with your car by just the warning light. However, instead of panicking, you should be grateful as it tells you to have your vehicle checked out as soon as possible. 

Read on to understand the techniques on how to reset the check engine light even without the help of a professional.  

1. Drive your car around

a car traveling on a highway

Let your car's ECU reset on its own by driving it around for at least 2 days, and the check engine light should be gone.

Cheat your car by driving for 30-50 miles, let it cool down for 3-4 hours, then go again. Instead of waiting for 2 days, this should do the trick.

If the light isn't turning green, it may mean you haven't repaired the original issue, or there's a new issue in the car you should check.

2. Fiddle with the ignition

a driver restarting hiscar

If driving around doesn't reset your check engine light, try turning off the car engine three times. Just insert your key in the ignition, turn it on for a second, then turn it off again.

3. Disconnect the battery

a mechanic disconnecting the battery

After trying the restart technique, try disconnecting the battery of your car. Mechanics sometimes disagree on how to do it. Some recommend disconnecting the negative (black) terminal while keeping it away from the positive (red) terminal.

Other mechanics swear by removing both terminals, then holding them together to discharge any remaining power on the ECU capacitor. However, this method will also erase additional memory stored in your car's ECU, and you need to reset your car's ECM too.

4. Use an OBD2 scanner

a driver using an OBD2 reader to check his car

The following technique is the easiest if you have an OBD2 scanner. Simply plug the device into the OBD2 port of your vehicle to use it to reset your check engine light.

You may use a portable scanner or an OBD2 scanner app on your cell phone after connecting the OBD2 Bluetooth or WiFi adapter. Most apps are free but have excellent features. However, if you want to enjoy more features, you can always get a paid app at a very affordable price. You can also use this on multiple cars, so it's very convenient.

Open your OBD2 reader, then clear the error codes listed on it. This step should clear your error codes and reset the check engine light on your car.

Here are some of our most recommended OBD2 scanners that you must try: Kobra OBD2 scanners for DIY mechanics and Innova 5510 for professional mechanics.

5. Remove the fuse

a mechanic removing a car's ECU fuse

This technique works only on older cars, though, so don't try this method if your car is a new model. Pull out your car's ECU fuse, then put it back on. Check your owner's manual to locate your car's ECU fuse.

If any of these techniques won't work, you may not have addressed your car's issue, or it detected new error codes. If this happens, you'll need a deep scan using OBD2 software from a professional mechanic.

Check Engine Light FAQ

Can I reset my check engine light?

Yes. Check the methods mentioned in the blog above to learn what works best for you.

How do I clear my check engine light without a scanner?

You can still clear your check engine light without a scanner. First, try driving your car around until your car's ECU recognizes that your vehicle doesn't have issues.

You can also try restarting your car a few times or disconnecting the battery on your vehicle.

Lastly, if your car is an older model (before the 2000s), try removing the ECU's fuse then replace it again. However, this is the last resort technique.

How long does it take for the check engine light to reset?

Depending on the technique you use, you can reset the check engine light in a couple of minutes to a day or two. Try other methods or have your car checked by a professional mechanic if it returns after a while.

Do check engine lights go away?

Yes. Just be sure to address your car's trouble codes, and your check engine line should be gone.


The check engine light is not your car's enemy. Instead, it is your safeguard, telling you something is wrong with your vehicle. Be sure to check your car with an OBD2 scanner before resetting your check engine light. If you found this article helpful, please share it with your friends. Drive safely!