Tag Archives: CEL

Check Engine Light On? How to Check It Yourself

Oh boy, there it is. The dreaded check engine light has appeared on your dash, taunting you with its amber illumination. Whenever you are driving down the road, and your check engine light pops on, you can’t help but feel a tightening in your stomach. Whether it’s from fear that you could break down at any second, or anger about the presumed dent in your wallet that the inevitable repair is going to create, that tightening only gets deeper. If it isn’t flashing though, it may not be the catastrophe you are dreading. The check engine light can illuminate for any number of reasons. Indeed, some automakers specify up to 4,000 different Diagnostic Trouble Codes (DTC)!

You don’t absolutely have to go to the mechanic or the dealership if you want peace of mind. All you really need, at least to start with, is a scan tool. There are a many different types of scan tools out there, some that are just simple code readers and others that connect to your smartphone or laptop that can give you much more vehicle information, such as fuel economy and trip information. In order to use a scan tool properly, follow our simple guide to checking your codes, finding the answer to your check engine light’s spontaneous appearance, and ease your mind.

  • Scan Tool to Help You Diagnose that Check Engine Light
    Scan Tool to Help You Diagnose that Check Engine Light

    After you have bought the scan tool that best fits your needs, go ahead and plug it into your car, in the slot under the dash. Your owner’s manual will give you its exact location, in case you don’t see it immediately. Turn the key to the “On” position, but don’t start your car. Once the electric power is on, the scan tool may ask for information about your vehicle. Follow the instructions for inputting your vehicle’s info, then move on to the next step.

  • The scan tool will give you a few options to choose from, essentially giving you different functionality from the tool. You will see the option for checking codes, which you should click on, to let you know what is happening with your vehicle.
  • Once your code or codes show up on the screen, write them down. Some of the more expensive scan tools will show you the code and what the code means. Others just give you a paper code list, normally in a book form. But in this technological day and age, it might be best to look the code up online. This will give you far more information on your problem and help you decide if it’s an issue you want to tackle yourself, or have a professional take care of.
  • Your scan tool can also reset your check engine light if you want it to. Doing this is only a cosmetic solution though, only eliminating a symptom, perhaps only temporarily, but not fixing the root problem. If you are trying to remove the check engine light, in order to pass inspection, don’t expect to trick anyone with a simple code clearing. After you clear a check engine light, you must drive your vehicle for its inspection and maintenance readiness (I/M) tests.
  • There should be an option on the scan tool for I/M status, allowing you to see when it will be prepared for the inspection. If all monitors say “Ready,” then you should be good to go. Still, if the problem is still there after clearing the check engine light, then the light will come back on, making it impossible to pass inspection. So if you are trying to see if it’s just a malfunction causing the check engine light to appear, then clearing the code can help with the troubleshooting. But always remember that clearing the code is not the same as alleviating the code’s origin.

So whether or not you get an expensive scan tool or just a simple code reader, having the ability to check your car’s codes yourself can make whatever the price of the scan tool you bought worthwhile. As a do-it-yourselfer, you can now use this information to diagnose and repair your vehicle.