How To Reset Check Engine Light

Let’s fix that dreaded nightmare, the check engine light

An illuminated check engine light.
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What happens after the “oh God, it’s the twinkling little yellow light of death” moment? What happens when that palpitation-inducing light just won’t go off, even after the vehicle has been completely repaired? Don’t hyperventilate just yet, as it might be a simple fix.

Fact: Check engine lights lead to gray hairs and sleepless nights. Just kidding, they’re important and that help you maintain your ride’s health and well-being. However, the check engine light is a finicky little bugger and sometimes won’t reset, even after the faulty part has been fixed. Understandably, this leads many to wonder just how they can reset the light and reclaim your REM sleep.

Never fear, as The Drive’s crack info team is here to help you restore order in your car’s sensor suite. So, who’s ready to vanquish thine illuminated enemy? 

A car's engine smokes as a man looks to camera.
Depositphotos

Here's what happens when you ignore your check engine light.

Resetting a Check Engine Light Basics

Estimated Time Needed: Half-hour

Skill Level: Beginner

Vehicle System: Electrical

What Is the Check Engine Light?

A check engine light, commonly referred to as a CEL, is a small warning light on your car’s dashboard that indicates that something is wrong with your car and is triggered by one of your car’s sensors. 

Reasons the Check Engine Light Turns On

There are countless reasons why your check engine light could turn on. Your car could have faulty wiring, a bad oxygen sensor, misfires, and/or a thousand and one other reasons. There’s no one definitive answer, unfortunately, and you’ll have to do some legwork to find out what’s what.

Everything You’ll Need To Reset the Check Engine Light

We’re not psychic, nor are we snooping through your toolbox or garage, so here’s exactly what you’ll need to get the job done. 

Tools

OBD2 scanner

Socket wrench set

Organizing your tools and gear so everything is easily reachable will save precious minutes waiting for your handy-dandy child or four-legged helper to bring you the sandpaper or blowtorch. (You won't need a blowtorch for this job. Please don’t have your kid hand you a blowtorch—Ed.)

You’ll also need a flat workspace, such as a garage floor, driveway, or street parking. Check your local laws to make sure you’re not violating any codes when using the street because we aren’t getting your ride out of the clink.

An OBD2 scanner coupled to a phone app.
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There's even an app now!

Here’s How To Reset Your Check Engine Light

There are a few different methods to clear a check engine light, but the two most common are using an OBD2 scanner and disconnecting and reconnecting the battery. Ready to get schooled?

Let’s do this! 

Using an OBD2

  1. Locate your car’s OBD2 port underneath the steering wheel or within the passenger-side footwell
  2. Plug in the OBD2 scanner and power it on.
  3. After inputting your car’s information, turn the car on and run a test to find the code responsible for the check engine light.
  4. Your car’s error codes should display. These error codes will tell you what triggered the code and what is wrong with the vehicle. You can then use them to fix the issue.
  5. For the intents and purposes of this article, let’s suppose you fixed the issue.
  6. After you’ve fixed the faulty part or parts, use the scanner to erase the codes. You can wait a moment to see if the code returns. If it doesn’t, you can proceed. If it does, well, you need to see if you properly fixed the issue.
  7. Start the car and see if the check engine light is out. It may take a few minutes for the computer to reset.

Turning It Off and On Again

Like the running gag on BBC’s The IT Crowd, have you tried turning your car off and on again by disconnecting and then reconnecting the battery? Let’s do this.

  1. Remove the negative cable from the negative terminal—the one with the minus sign. Depending on the design of the battery, you may need a wrench to loosen the cable-free. 
  2. Remove the positive cable from the positive terminal—the one with the plus sign. If you are using a tool like a wrench, make sure the metal doesn’t contact the terminal as it will spark.
  3. Wait 15 to 30 seconds.
  4. Reconnect the positive terminal. 
  5. Reconnect the negative terminal. 
  6. Test the car and see if the check engine light isn’t on.

Get Help With How To Reset Check Engine Light From a Mechanic On JustAnswer

The Drive recognizes that while our How-To guides are detailed and easily followed, a rusty bolt, an engine component not in the correct position, or oil leaking everywhere can derail a project. That’s why we’ve partnered with JustAnswer, which connects you to certified mechanics around the globe, to get you through even the toughest jobs.

So if you have a question or are stuck, click here and talk to a mechanic near you. 

An illuminated check engine light.
Depositphotos

That evil little light.

Pro Tips For Resetting Your Check Engine Light

Well before the advent of the OBD2—yes, we’re old, we know—The Drive’s editors used to scrape and damage our knuckles diagnosing check engine lights. Here are our pro tips for diagnosing a check engine light.

  • Head to your local auto parts store and rent an OBD2 scanner to see what’s what. The staff will also help you read the code. 
  • If your car is pre-OBD2, prepare for a long and drawn-out process of checking your car’s electrical connections and sensors—sorry.

FAQs About Resetting a Check Engine Light

You’ve got questions, The Drive’s crack info team has answers!

How Much Does It Cost To Reset a Check Engine Light?

That depends on whether it’s an errant error code or there’s something actually wrong with your car. Resetting the check engine light after you’ve already repaired your car, however, costs nothing if you already have an OBD2 scanner. If you don’t, you can purchase ($30-$70) or rent one from your local auto parts store.

How Often Do You Need To Reset Your Check Engine Light?

You only need to reset your check engine light after it comes on. If you’re routinely resetting it, you may have a larger issue you need to take care of.

Will a Check Engine Light Reset Itself?

If you own a modern vehicle and have already fixed the issue that caused the check engine light, the light may reset itself after a few miles, as normal operations return. 

Can You Reset a Check Engine Light Without Disconnecting the Battery?

If your car has an OBD2 outlet, you won’t have to disconnect the car’s battery. If your car is pre-OBD2, then you may have to disconnect the battery. However, that’s a simple process and you can follow The Drive’s guide to Changing a Car Battery or scroll back above.

Featured Products

Ancel AD310

BAFX Products Car Diagnostic Tool

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Got a question? Got a pro tip? Send us a note: guidesandgear@thedrive.com