Is your check engine light on? 

check engine light on
Check engine light, also known as Service Engine Soon light. 

To find out why your check engine light has come on, you need to use a scanner to retrive the Diagnotic Trouble Codes (DTCs). This is a very simple procedure that takes about five minutes.

In this article, you will learn how to find out what the check engine light is trying to tell you. 

Get an OBD-II Scanner

OBD II scanner

To find out why your check engine light is on, you will need an OBD-II scanner. Many auto parts stores will let you borrow a scanner for free or you can buy an inexpensive OBD-II scanner and keep it in your glove box. We are using a sophisticated scanner, but honestly, even a $15 scanner will be able to retrieve check engine codes. 

If you don't want to buy a scanner, here are some auto part stores that will scan your car for free or let you borrow a scanner. 

  1. Aamco Auto Repair Center
  2. Advance Auto Parts
  3. AutoZone
  4. O'Reilly Auto Parts
  5. Pep Boys Auto Parts
  6. Napa 

Click on any of these stores to find a location near you that will check your engine light for free. 

How to Diagnose Check Engine Light Yourself


  1. Locate the diagnostic port under the dashboard on the driver's side. All cars have this port. Sometimes it is hidden in the fuse box on the driver's side, but in most cases, the port is right under the dashboard. obd ii port


  2. Plugin your OBD-II scannerdiagnose check engine light for free yourself


  3. Turn on the ignition but do not start the engine. On cars with the Start/Stop button, you need to press the button without pressing the brake pedal. 

    turn on ignition

  4. Your scanner will take a minute to communicate with the on-board diagnostic system. 
  5. Select OBD-II then Read Codes from the main menu. read check engine codes free
  6. Write down all the codes. Pay attention if they are Stored or Present. Check engine  codes

Stored codes mean that an issue was detected in the past, but currently, it is no longer an issue. These codes will typically reset on their own after a few days of driving. 

Preset codes mean that the problem is current, and it needs to be addressed.

You may be tempted to erase these codes, but clearing present codes without fixing the car is not a solution. The codes will return either as soon as you start the engine or can take up to two days, but they will eventually return if your car problem isn't fixed. 

If your check engine light comes on, don't ignore it but read the codes as soon as possible. If the check engine light is flashing, it means that driving with the check engine light on can cause serious engine problems. 

Don't ignore the check engine light. The codes stored on the On-Board Diagnostic (OBD) system can help you find out what is wrong with your car. 

Even if you don't plan on fixing your car yourself, knowing why your check engine light is on can help you feel more confident when you talk to your mechanic. 

On some models, the check engine light may be referred to as the service engine soon light.