Car ProblemsOBD2 Codes

Check Engine Light: Everything You Need to Know

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We’ve scanned over 18 million vehicles for check engine lights with the FIXD OBD2 scanner and app. These are the 5 most common check engine errors.

The check engine light can come on for thousands of reasons, but with the help of a scanner such as the FIXD sensor, you can narrow it down to a hand full of reasons it’s on. The check engine light’s main purpose is to let you know that your vehicle is having a problem.

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5 Most Common Reasons for Your Check Engine Light to Come On:

Engine Code



SEVERE - stop driving immediately

Random, Multiple Misfire Detected

MODERATE - get this fixed within a week to avoid engine damage

Catalyst system efficiency below threshold (Bank 1)

MODERATE - get this fixed within a week to avoid engine damage

Bank 1 has too much air or not enough fuel

MODERATE - get this fixed within a week to avoid engine damage

System Gross Leak Evaporative System Malfunction

SEVERE - stop driving immediately

Cylinder 1 is experiencing misfires

Other Common Problems

  • Loose gas cap
  • Engine misfire
  • Faulty emissions components
  • Loose or disconnected electrical connectors

Can I Drive with the Check Engine Light On?

This depends on how severe the fault is and what triggered the light in the first place. That’s why it’s critical to use a tool like FIXD to find out as soon as possible what your check engine light means and get it properly diagnosed and repaired at a trustworthy shop. Click below to search for the most common check engine errors associated with a specific vehicle.

Most Common Engine Error Codes By Make

What Should I Do If My Check Engine Light Is On?

There are thousands of reasons why the engine light is on, from a loose gas cap to a misfiring engine. If your check engine light is on, don’t panic. Instead, follow the steps below and get it to a trusted and RepairPal Certified repair shop for inspection as soon as possible.

> Find a RepairPal Certified Shop Near You

What the Check Engine Light Means

Your car’s check engine light is part of the onboard diagnostics system (OBD2). Since 1996, all gas-powered vehicles are required to have this computer that communicates with your engine to notify the driver or automotive technician of any issues.

When your check engine light comes on, it means that the computer has detected a problem. Along with a warning light on your dashboard, the OBD2 system stores the diagnostic trouble code associated with that problem. With the right tools, you can read this code to understand what’s wrong with your car and how serious the problem is.

Instantly Diagnose Your Check Engine Light

Read and clear 7000+ check engine light codes with the FIXD Sensor and free app.

How to Read Your Car’s Engine Warning Code

To read the diagnostic trouble code stored by your car’s computer, you have a few options.

1) Go to your local mechanic. As part of their diagnostic fee, they will use a professional OBD2 scan tool to read the code and identify the cause. However, if you aren’t near a repair shop or haven’t yet established a relationship of trust with the shops in your area, this might not be the best option.

2) Go to a nearby auto parts store. Most of these shops will give you an engine code readout for free. Again, if you break down in the middle of nowhere, this isn’t an option. There’s also a concern that these shops may have ulterior motives to upsell you on products you may or may not actually need after they interpret your check engine light for you.

3) Get your own check engine scanner like FIXD. There are many affordable engine light scanners available for everyday drivers that plug into your car’s OBD2 port to tell you what your check engine light means. Unlike other car scanners, the FIXD Sensor comes with a free app and connects to any iPhone or Android smartphone to tell you what’s wrong with your car in plain English. You can even clear the check engine light right from the app.

How the FIXD Check Engine Scanner Works

The FIXD car scanner plugs into the OBD2 port usually located under the dash on the driver’s side of your vehicle. Click here to find out how to locate your OBD2 port.

Once it’s connected to your car, the FIXD Sensor and free mobile app tells you what your check engine light means in plain English so that you can walk into the repair shop armed with accurate, detailed information.

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See How Serious It Is

Find out how serious your code is and whether or not it’s safe to keep driving.

Get Maintenance Alerts

FIXD notifies you when it’s time for an oil change and other routine maintenance based on your make, model, and mileage.

View Live Data

Monitor the health of your car in real time with FIXD’s live data tool. See oxygen sensor voltage, fuel trims, vehicle speed, and more.

Does FIXD Work with Your Car?

FIXD is compatible with all gas-powered vehicles 1996 or newer and all diesel engines 2008 or newer.

Is It Safe to Drive with My Check Engine Light On?

Since the check engine light is tied to your car’s individual onboard diagnostics system, you’ll need a code reader or OBD2 scan tool like the FIXD Sensor to understand the severity of the issue and whether or not you should keep driving.

However, if the check engine light is blinking while you’re driving, you should pull over as soon as you safely can to check for low oil or overheating. Your car may have a red warning light to indicate that you should stop driving immediately or a yellow light to indicate further investigation is needed.

If you experience driveability issues along with the engine light, reduce your speed and take it easy on the engine to avoid potentially bigger problems.

Lastly, be sure to check your gas cap. A loose gas cap is one of the most common reasons for a check engine light and easy to fix. This light happens because the engine detects a leak in the evaporative emissions system.

How Can I Reset the Check Engine Light in My Car? 

You may want to clear the check engine light if you think you’ve resolved the issue (i.e. tightening a loose gas cap). Resetting the light and driving around to see if it comes back on will let you know whether or not you have fixed the problem.

If you plan on doing your own car repairs, the easiest, cheapest way to reset the check engine light is with FIXD. Most shops will charge $100+ to reset this for you, but you can do it for free inside the FIXD app.

To clear your check engine light with FIXD, simply click “Clear Engine Light” on the details page after you’ve performed an engine scan. If the code is cleared but the issue has not been resolved, you might see the warning light reappear after driving a few miles. 

Decode Your Check Engine Light with FIXD

Still wondering what to do about your check engine light? Take the first step to clarity by getting FIXD, America’s favorite check engine scanner and app. Get detailed engine diagnostics, plain English code descriptions, issue severity warnings, and so much more. Learn more about the FIXD Sensor and mobile app today!

Frequently Asked Questions

How do I find out why my check engine light is on?

  • You can take it to a repair facility or parts store to have them pull the codes with a scanner, or you can get your own scanner and pull the codes yourself. Check out the FIXD sensor for a quality built code scanner.

What does it mean when the check engine light flashes?

  • This means the engine is misfiring and should not be driven. If you continue to drive with the check engine light flashing, you could cause the catalytic converter to fail and need to be replaced.

How serious is the check engine light?

  • It depends on which code the check engine light is on for. It could be something as simple as a loose gas cap or something as serious as a misfire.

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.

Kate McKnight
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.

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    1. Good information, and now I have a better understanding of the signal

      1. That’s great to hear, Pat! 🙂

    2. How do I get the scan on my FIXD app?

      1. Hey David, simply plug FIXD into your car’s OBD port, add your vehicle info, and hit scan on the app you should’ve already downloaded to your phone. Check out our Getting Started Guide for more info!

    3. Trying to get this to read errors on my bmw 1250rt motorcycle, need to reset oil change light

    4. I just hate my oil changed 2 and 1/2 weeks ago my light coming on saying change engine oil is this a sensor going out?

      1. No just get your owners manual and reset your reset your engine oil light.

    5. Thanks to this small, but smart device, at least it tells me the major defects on my car before I get to the mechanic who guess and cost you more money.

      1. Glad to hear FIXD is helping you Terefe!

    6. Will not connect to my 2013 for two smart car redid 3 times now. What’s up?

      1. Hey Kevin, so sorry to hear that you are having connectivity issues. Please make sure you have the most updated version of the FIXD App additionally, please make sure you are connecting through the FIXD App and not through the Bluetooth menu of your smartphone. If you have taken these steps and are still experiencing issues, please reach out to our support team here:

    7. Mine not picking up codes or flashing blue light on FIXD gadget!
      Can’t tell if plug is transmitting power or not!
      Engine has a semi smooth idle but and exhaust flow.
      Could it be bad gas from sitting awhile?
      Wish blue light on gadget would show where it lights.
      If calling text only with FIXD caller id name as I am deaf and get a lot of crank voice calls I cannot identify or answer.. they go to spam.
      Thank you!

    8. It didn’t do anything to help me
      It told me to take it to a garage and have them check it out wtf did I buy this for

      1. Hi Troy, there are some things that are best handled by a professional and some errors that FIXD cannot detect. FIXD can’t help you fix all your car problems, but it does give you clarity so you can walk into the repair shop with confidence.

    9. Can I use the same fixed on more than one vehicle

      1. Yep! You can use the same device on multiple vehicles by unplugging it and plugging it into another then adding that second vehicle to your account. The benefit of having multiple sensors is that you can keep them connected and easily monitor car health from your app.

    10. My car runs great it’s just the check engine light is on I wonder how I can fix that

    11. My check engine light is on but my fixed says no errors found

    12. I tried to connect and entered the code on the back of the unit and it said that it was an invalid code so what’s the use of it I wasted my money

      1. I’m sorry to hear you’re having issues connecting the device. Please contact our support team here. They’d be happy to help you out and resolve the invalid code issue!

    13. My display says “check fuel cap” and the wrench-maintenance required icon is lit. However, my Fixd device indicates nothing is detected. I checked my fuel cap and it’s closed tight. I wonder what I am missing. Any suggestions?

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