Check engine light on? This guide shows you how to quickly reset the check engine light without disconnecting the battery.
Every gas-powered passenger vehicle made since 1996 comes equipped with an onboard diagnostics (OBD2) system for monitoring vehicle health. When there’s a problem with your car, this onboard computer causes a “check engine light,” also known as the malfunction indicator lamp, to pop up on the dashboard.
Along with triggering the check engine light, the OBD2 system will store a corresponding engine fault code so you can diagnose the issue. Since simply resetting the check engine light won’t fix the underlying issue, you first need to understand what your check engine light means to clear it effectively.
What Does Your Check Engine Light Mean?
At FIXD, we’ve scanned millions of vehicles for check engine lights. Here are 20 of the most common reasons for a check engine light based on our data. One of the most common causes of any check engine light is a loose gas cap, so be sure your gas cap is screwed on tightly and see if the light turns off.
There are many different types of warning lights, from tire pressure warning lights to a low oil pressure light to the ABS light. But if you’re seeing a light that looks like an engine or says “check engine,” pay attention to the color.
Solid Check Engine Light
If your check engine light is illuminated solid, then there is an OBD2 code in the system. This could be something easy to fix or it could require more diagnostics. A mechanic can read the code for you, or you can use FIXD to read it yourself and learn more about your problem before going to a shop.
Blinking or Flashing Check Engine Light
If your check engine light is blinking, there is an active misfire. To prevent engine damage, do not drive the vehicle or attempt to reset the check engine light until this misfire issue is resolved.
For more help diagnosing a misfire see the following fault code pages:
If you just repaired an issue, but the check engine light is still illuminated, you might want to clear it in order to determine if your repairs solved the problem. We’ll show you three ways to do this as simply as possible.
How to Reset Your Check Engine Light with an OBD2 Scan Tool
If you want to reset your check engine light without disconnecting the battery or going to a repair shop, this option is the most efficient and thorough. A scan tool will not only clear the check engine light, but it will allow you to see why the check engine light is on in the first place. There is a reason behind why it is on, and if you don’t resolve the problem, the light will come right back on. If you’re looking for an affordable, easy-to-use scanner, check out our FIXD Sensor and free OBD2 app.
Enter the vehicle through the driver’s door and locate your OBD port. It should look like the picture below, and it is usually around where your shins would be if you were sitting in the driver’s seat.
Plug your scan tool into the OBD port and turn the key to the on position (gauges should be lit up, a/c will blow if it’s on, but the engine is off)
This step will vary based on the tool you’re using, but select “READ” and scroll through the codes that are active on your vehicle. Write down each code in case the codes come back or change later down the road.
Now select “CLEAR” on your scan tool and clear the codes. At this point, the Check Engine Light should be off, and you have successfully reset your check engine light. If the light comes back on, you will need to diagnose and repair the concern that is causing the code.
Pros & Cons of Resetting the CEL with an OBD2 Code Reader
|Instantly tells you why your check engine light is on||Requires you to purchase FIXD or another OBD2 scanner|
|Translates your OBD2 code into simple terms on your smartphone|
|Doesn’t require you to reset your radio presets, clock, or seat memory|
|Works from inside the vehicle – no dirt, no fuss, no need to pop the hood. You can even do it while it’s raining!|
How to Reset the Check Engine Light by Disconnecting the Battery
Last but not least, if you don’t have an OBD2 scan tool and you’re far from a local auto parts store, you can reset your check engine light by disconnecting the car battery. It’s not ideal, and it will reset your clock, radio preset, and seat memory, but it’s relatively easy to do.
Locate your vehicle’s battery. For most vehicles, it will be located under the hood, but for some, it may be located in the trunk or in another area of the car.
Disconnect the negative terminal of the battery. It will usually be labeled with a (-) negative symbol and colored black.
Touch the negative cable end you just disconnected to the positive terminal still connected to the battery. The positive terminal will be labeled with a (+) positive symbol and colored red. Hold it there for 1 minute. This will fully drain the vehicle’s capacitors and fully reset all the vehicle systems.
- Tech tip: If you can’t touch the negative cable end to the positive cable end, disconnect the positive cable end and touch the two cable ends together.
Reconnect the battery terminal end(s). Connect the positive terminal first (if removed), followed by the negative.
Start the vehicle and verify that the Check Engine Light is off. If the light comes back on, you will need to diagnose and repair the concern that is causing the code.
Pros & Cons of Resetting the CEL by Disconnecting the Battery
|If you have a couple of wrenches, it costs nothing to do||Resets the clock, radio presets, and seat memory|
|Time-consuming (takes 10-15 mins) compared to seconds with a scan tool|
|May be difficult if the battery is not easily accessible|
|May require you to get your hands dirty|
Other Ways to Reset the Check Engine Light for Free
Option A: Go to Autozone
Wondering if the local Autozone can turn off a check engine light? The answer is yes, but… there are a couple things to remember:
- Local auto parts stores will typically offer to read your codes for free, but not all locations will clear the light due to liability issues. Some of them don’t even carry code readers that can reset the check engine light.
- Salespeople are often incentivized to sell you parts while you’re in the store, whether or not it’s clear they are going to fix your check engine light (and may actually be a waste of money).
Option B: Drive until the Light Goes Off
While it’s not recommended, sometimes driving the vehicle for a few days allows the vehicle to do its own self-check. If it decides the concern has been resolved or is no longer an issue, it will turn off the check engine light on its own. If the light comes back on, you will need to diagnose and repair the concern that is causing the code.
While this option requires no cost or extra effort, it comes at a risk. If there is a serious problem with the vehicle, driving on it for several days could cause serious damage. It’s always best to play it safe and find out why your check engine light is on as soon as possible.
Diagnose Your Check Engine Light in Seconds with FIXD
For the quickest, easiest way to not only reset your check engine light, but also find out why it’s on in the first place, get FIXD. This easy-to-use OBD2 scanner and app lets you instantly scan your car for check engine codes and other problems, then translates them into plain English on your phone. FIXD even sends you handy maintenance alerts so you can avoid costly problems altogether. Learn more about the FIXD Sensor and free mobile app today!
Wife, mom, Content Manager & Senior Copywriter at FIXD. From the garage to the gym, I love helping people learn and grow. Dream car: ‘69 Acapulco Blue Mustang.