When the Check Engine Light (CEL) appears on your dash, it means that you have something to take care of. The onboard diagnostics (OBD) system is checking the different components of your car to verify that they are operational.
If there is a fault then you will get a warning message on your dash or information display. That’s when you need to know how to reset the check engine light.
In this article, we provide you with some options, and also, why you should deal with the problem first, if you have the light return, and answer some questions you have likely wanted to know about.
The Importance Of Fixing The Problem Before A Reset
It is never a good idea to ignore what the Check Engine Light is trying to alert you about. This system is meant to alert you every time the fault occurs and gives you the ability to keep your vehicle performing as it should. So, you should address the problem so that the warning light can be reset for good.
By ignoring the problem, you may be risking:
- Long term damage from allowing the engine, transmission, or any other valuable systems, to deviate away from being operational. If you need new spark plugs for your car and choose to ignore this, you may find you need to replace a catalytic converter later down the road at a considerably higher expense.
- The car may fail a safety inspection. If your car fails a safety inspection, there is a chance you may not be legally allowed to drive your car in your state because you are unable to maintain some reasonable level of safety.
- Your vehicle could possibly fail an emissions checklist. It is illegal to drive your car after it has been flagged for emissions if it is required in your state, and it also is not good for the environment.
- Your car will not be running as effectively as possible which could involve excessive fuel consumption.
In addition, while the light is on you will not know if another issue develops. Therefore, if you have decided to ignore the warning light, because it’s just on for a minor issue, you won’t even be alerted about another issue when and if it breaks and may be worse.
How To Reset Check Engine Light?
Use an OBD2 Scanner
If you have a compatible OBD2 scanner, you can reset the Check Engine Light in a matter of seconds.
If you have a scanner and want to turn off the codes, here are the steps:
- Plug your scanner into your vehicle’s OBD2 connector. Normally, you can find it near the floor under the steering wheel, on the left side.
- Put the ignition in the ON position.
- After connecting, press the READ button on your scanner to retrieve the last codes. After you receive those, all of the stored diagnostic trouble codes (DTCs) will be there.
- Erase the trouble codes that you have repaired by using the ERASE/CLEAR button on the scanner.
Once you have the codes erased you can turn the ignition off, and back ON to see if the light has turned OFF.
Alternatively, you can plug the scanner back in make sure all of your codes have been erased. If the codes immediately come back, you know for a fact that you have not repaired the problem.
Battery Disconnection Method
Not able to obtain a scan tool and want to reset the Check Engine Light? The quickest way to reset your Check Engine Light, would be to remove the battery terminal. This process will usually only take a few minutes and should reset the engine control module on most current model vehicles.
Notice, before disconnecting the power, that with the battery removed you may lose some car settings. This may include setting the stereo preset, seat memory, or even the clock.
The following are steps to take:
- Remove the negative battery terminal.
- Once the terminal is disconnected, completely drain electricity from the vehicle’s capacitor, by pressing the car horn for 20-30 sec. You could turn on the lights to discharge, as well.
- Now walk away for about 15 minutes.
- Connect the battery terminals and ensure the terminal is secure.
- Start the vehicle.
If the Check Engine Light doesn’t clear, either you didn’t fix the issue, or you need to try one of the other options.
Cycling The Ignition On And Off
You can also perform a hard reset without a compatible code scanner. By cycling the ignition on and off multiple times, the light may go away. Each automaker will have more specific steps for this so you may have to do some more digging.
Typically, you will cycle the ignition on and off a few times with a few seconds in between. After you finish, the Light may be gone.
Drive Your Car And Let The Light Turn Off By Itself
If you fixed the underlying issue, you may be able to let the Check Engine Light eliminate itself entirely. Once you do a little driving, the self-checks should register to the computer that everything is fine. That will trigger the light to turn back off.
Keep in mind that this could take some time. Depending on the problem, it may take several days for the computer to register that the fix is applied and determine that the issue is fixed.
As an example, repairing a problem with the oxygen sensor won’t reset the code until the ECU determines that the fault is repaired.
If your Check Engine Light is still illuminated after driving for three days, the issue may not be corrected. If you are unsure what to do next, you can try some of the other methods listed or take it to a mechanic.
Pulling Fuse
There is also the option of pulling the fuse for the Engine Control Unit, which may reset the unit and erase the codes. However, the fuse repair method usually only works on older cars.
If you are not sure where the fuse is located, you can look it up in the factory service manual. It only takes a few seconds to pull a fuse, so it is worth a shot.
What To Do If the Check Engine Light Comes Back On
Finding out your Check Engine light is turns off will bring you so much relief to know your vehicle is repaired, until it turns back on a few days later; this happens a lot due to not fixing the original problem. If you haven’t purchased a code scanner, you should!
If you are absolutely positive you don’t want to spend any money for a code scanner, there are many auto parts stores that offer free car diagnostics and can tell you what fault is present in your vehicle.
You could also go to your local mechanic to ask them to scan the codes; there will be a service charge for them doing that. The important thing to know, whenever the Check Engine Light is illuminated, it means the computer has noticed a fault.
You want to look into what’s causing it so you don’t damage anything else. Some trouble codes are fairly easy to understand and remedy, while others are much more complex. That’s why we recommend you also consult our free online trouble code library while trying to repair your machine.
Can You Reset the Check Engine Light Without a Scanner?
Yes, although a scanner is the least complicated (and safest) way to deal with the Check Engine Light.
If you have no scanner, you may choose to disconnect the battery, pull a fuse, run through an ignition cycle or even drive the vehicle for a few days. All of these require you to have repaired what caused the code in the first place!
How long does it take for a check engine light to reset itself?
That depends on the car you drive. With some cars, a check engine light might need some time to clear itself up, anywhere from 10 to 100 miles of driving.
The engine computer needs to do a check of the system that was malfunctioning and needs to register that it is once again operating normally. Some of the systems are checked all the time while other systems have an occasional check, maybe only once per ignition cycle.
Do you need to drive to clear a check engine light?
No, there are other ways to clear the Check Engine Light without having to drive the car anywhere. If you have a compatible code scanner, you can simply reset that system without driving anywhere. Otherwise, you may have options to pull a fuse, cycle the ignition or disconnect the battery for a short term.
How do you reset the check engine light with the gas pedal? Some vehicles have a reset method by way of cycling the ignition and pressing on the gas pedal. Finding this method would involve reading the procedure in your factory service manual. Otherwise, wasting your time trying a method that may or may not actually does work for your type of vehicle is futile.
Will AutoZone reset the check engine light?
It depends. Many AutoZone locations will provide diagnostic scanning for free using a compatible code scanning device. They will tell you what codes are present and may suggest a few fixes to save you some money.
However, some locations will not reset the check engine light, typically for liability reasons. Still, it may be worth a try if you do not own or have access to a code scanner.
Is the check engine light an easy fix?
It depends on what caused the check engine light to illuminate in the first place. If the cause was a lose gas cap, or damaged gas cap, that is a relatively easy fix.
Alternatively, if you were having problems with a system being too lean “or” too rich, troubleshooting could be much more difficult. There may also be some warnings that lead to costly repairs, like when the vehicle is in need of new catalytic converter.
After you have fixed the fault related to the diagnostic trouble codes in the computer. It is now time to reset the Check Engine Light. There are several methods of resetting the Check Engine Light, the easiest method involves using a code scanner.
But not everyone has or is able to get access to a code scanner. So you may need to use a bit of trial and error to find another method for turning off your cars’ check engine light.
Whether you disconnect the battery for a period of time, or pull a fuse, or cycle the ignition or simply continue to drive the vehicle, you may find some respite from the annoying check engine warning light.
Still, if you cannot seem to turn it off, you may not have fixed the problem, or you need to take the vehicle to your professional mechanic.