Free Check Engine Light Testing | O'Reilly Auto Parts

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Ignoring a solid or flashing Check Engine light on your vehicle can lead to safety issues, a roadside breakdown, or costly repairs. If you are near an O’Reilly Auto Parts location and your Check Engine light is on, our trusted parts professionals can scan and read your illuminated Check Engine light for free with our exclusive O’Reilly VeriScan™ code reading service.

O’Reilly VeriScan can provide you with a detailed report of possible causes and fixes for your illuminated Check Engine light. This report is printed to review with the parts professional at the store, and you will also receive a digital copy of the O’Reilly VeriScan report sent to your email for your convenience.

Your O'Reilly VeriScan™ report can help you understand what parts and services are necessary to restore your vehicle’s performance, and we can help you find the best parts and offer the advice you need to get the job done right. If you aren’t comfortable performing any necessary repairs yourself, we are also happy to recommend a local repair shop. To learn more about what the lights on your dashboard mean, you can also check out our information on
dashboard warning lights and common Check Engine light codes.

Get an O'Reilly VeriScan at your Local Store

If the Check Engine light comes on in your vehicle and you can safely drive to your local O’Reilly Auto Parts location, we can help you better understand the problem with O’Reilly VeriScan. Vehicles 1996 or newer can be scanned by plugging our O’Reilly VeriScan code reader into your OBD-II system – just ask for a free Check Engine light test. The parts professional will follow you to your vehicle with an OBD-II code reader, hook up the scanner to your vehicle’s OBD-II port, and provide you with the diagnostic trouble codes (DTCs).

The diagnostic code or codes are run through a comprehensive database of over 650 million verified fixes in our store, and the fixes and diagnostic information will be explained in your printed O'Reilly VeriScan report. After your O’Reilly VeriScan report is complete, you will be able to review your report to find ASE technician-verified solutions, repair options, and suggested parts. Our parts professionals can also help you find the parts and tools you need to complete your repair. If you are not confident performing the repair yourself, or if additional diagnosis is necessary, we would be happy to refer you to a trusted local repair shop.

If your vehicle is older than 1996, it will likely not have the correct OBD-II diagnostic port or DTC protocols. However, we may be able to help you find a scan tool that can read older diagnostic protocols, such as OBD-I, or help you find a local repair shop that has the correct tools to diagnose your vehicle.

O'Reilly VeriScan is a free service available at any time during the stores posted operating hours.
No appointment is necessary to receive this service, but wait times may vary depending on staffing.

An O'Reilly employee holding an OBD scanner to diagnose a Check Engine light.

Can O’Reilly Auto Parts Clear My Check Engine Light Codes?

When you have your Check Engine light tested at O’Reilly Auto Parts, our Professional Parts People can read your codes and provide an O’Reilly VeriScan list of possible solutions, but legally they are not allowed to clear the DTCs causing the Check Engine light with the code reader.

Except where prohibited by law, customers are welcome to use our code readers to clear the codes themselves, which may temporarily turn off the Check Engine light. If the problem is more extensive than a sensor that needs to be reset and the issue has not been addressed, the Check Engine light is likely to reactivate. Even if the Check Engine light is off for some time, it may turn back on as soon as the issue returns or the next time the car is started.

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What Happens If I Drive With The Check Engine Light On?

Even if your vehicle seems to be running fine, you should always get the issue diagnosed as soon as possible. Depending on what is causing the Check Engine light to turn on, you may be able to continue driving your vehicle for a short amount of time without causing any further issues or damage.

If your vehicle is not running properly, you should drive it as little as possible until you can get it to a repair shop or O’Reilly Auto Parts for a free O’Reilly VeriScan Check Engine light reading and have it checked for Diagnostic Trouble Codes (DTCs). This is especially true of a blinking Check Engine light, which typically indicates issues that require immediate attention and risk catastrophic engine failure. Learn more about what to do when your Check Engine light is on with our helpful article.

What is a Diagnostic Trouble Code (DTC)?

Since 1996, automotive manufacturers have used OBD-II protocols to allow for the vehicle’s computer system to self-diagnose engine or sensor issues by using Diagnostic Trouble Codes (DTCs). The DTCs are sent to the engine control module (ECM) by the sensors and modules that monitor and control the engine’s performance.

These codes are stored, allowing them to be read by a diagnostic scan tool or code reader through a universal connector which is normally located under or near the dash of your vehicle. Once the codes have been read, you can determine what repairs, if any, need to be completed to fix your vehicle and deactivate the Check Engine light.

Even if your vehicle was made before 1996, it may still have a diagnostic port. The diagnostic systems of these vehicles use older OBD-I protocols that may require a different diagnostic tool or special diagnostic procedures, and unfortunately, cannot be scanned with the O’Reilly VeriScan tool used at your local O’Reilly Auto Parts.

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An O'Reilly employee holding a VeriScan report and presenting it to a customer.

What Causes the Check Engine Light to Turn On

The Check Engine light will illuminate when a sensor communicating with the engine control module (ECM) detects a component failure or reading outside of its normal range. Any issue that causes the Check Engine light to illuminate should be checked as quickly as possible, especially if the issue causes misfires or poor engine performance. The most common causes of a Check Engine light include a loose gas cap or faulty oxygen sensor, but there are other sensors, modules, and more that could trigger the Check Engine light.

Engine Misfiring
Engine misfires caused by bad spark plugs, spark plug wires, or ignition coils can cause the Check Engine light to activate immediately, and in most cases a misfire will also cause a flashing Check Engine light to indicate an urgent issue. Misfires and reduced engine performance may also be caused by an air-fuel mixture that is too lean or too rich or a failing O2 sensor. Any time the engine is not running properly, the Check Engine light is likely to activate. You can learn more about what causes an engine to misfire and more with this helpful article.
Failing Engine Sensors & Electronic Modules
Even if the engine in your vehicle is running correctly, the Check Engine light may activate if an electronic module or sensor begins to fail or produces incorrect or inaccurate readings. Some sensors, such as the mass air flow (MAF) sensor and the engine knock sensor, may affect how the engine runs as they begin to fail. This can also result in a Check Engine light, and it may even flash if the issue is severe enough.
Emissions Problems
The emissions system is monitored by oxygen sensors and exhaust gas recirculation (EGR) sensors. If the air-fuel mixture is not correct or there is insufficient EGR system flow, the Check Engine light will activate. More serious issues, such as a clogged catalytic converter, will also affect the performance of your vehicle, and may turn on the Check Engine light.

Car Dash with Check Engine Light On

What Does a Flashing Check Engine Light Mean?

A flashing Check Engine light is normally a notification of a serious issue that could lead to catastrophic engine failure, and needs to be addressed immediately. It is recommended that you drive your vehicle as little as possible or drive it directly to a repair shop if your Check Engine light is flashing. Flashing Check Engine lights can be caused by an issue that presents as an engine misfire or reduced engine performance, however, there may be a variety of serious problems that could lead to catastrophic engine damage if not dealt with promptly.

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How Much Does Diagnostic Testing at a Shop Cost?

Many repair shops will charge a diagnostic fee to read the DTCs causing the Check Engine light to activate. The national average cost for diagnostic testing at repair shops is around $100, or typically one hour of shop labor. While some repairs may need to be done at a repair shop, you can save money in many cases by receiving a free O’Reilly VeriScan Check Engine light test at a local O’Reilly Auto Parts location and performing the repairs yourself.

At O'Reilly Auto Parts, we offer free diagnostic services using our O'Reilly VeriScan tool, which can read your vehicle's codes and help you understand the problem. This service is available for more than just your Check Engine light.

ABS and Transmission Code Scanning with O’Reilly VeriScan

In addition to Check Engine light testing at O’Reilly Auto Parts, you can stop in to get your ABS or transmission codes scanned with O’Reilly VeriScan. If your ABS light or transmission light is on, stopping by O’Reilly for a free O’Reilly VeriScan can help you better understand the problem, and our parts professionals can then help you find the parts and tools you need to make your repair.

Common ABS Code Causes
If your ABS, or Anti-Lock Braking System, light is on, it could indicate low brake fluid, faulty wheel speed sensors, a malfunctioning ABS module, pump, or valve, or other problems with your vehicle’s ABS system. This may prevent your ABS from working as it should, extending braking distance and allowing your vehicle to skid while braking in poor weather conditions.

Our parts professionals are equipped with O’Reilly VeriScan, which functions as an ABS scan tool when connected to your car’s OBD-II port. This tool can scan your ABS codes to help you diagnose the problem, and also identifies the most likely solution. Stopping by O’Reilly Auto Parts to get your ABS codes scanned can help you get to the bottom of your illuminated ABS light and make any necessary repairs to keep you and your vehicle safe on the road.
Illuminated Maintenance Lights
Suppose your maintenance light is illuminated on your vehicle’s dashboard. In that case, your vehicle is likely nearing the recommended mileage or scheduled interval for a routine service, such as an oil change, fluid check, or tire rotation. Completing regular maintenance tasks on time is an important part of owning a vehicle, and helps ensure your car is performing its best on the road.

If your maintenance light comes on, O’Reilly VeriScan can read or clear your maintenance light, and the report you receive will also provide a list of suggested maintenance items recommended for your vehicle based on its mileage. Our parts professionals can help you find the parts, fluids, and tools you need to complete your maintenance task at home. If you’re not comfortable completing these services yourself, we can also recommend a local shop.
Common Transmission Code Causes
Scanning transmission codes requires a multi-system OBD-II diagnostic tool, and an O’Reilly VeriScan can be completed at any O’Reilly Auto Parts store. It only takes a few minutes, and the parts professionals at O’Reilly Auto Parts can then identify and provide the transmission codes to help you make your repair.

If your vehicle’s ABS or transmission warning light comes on, or if you’re experiencing any of these symptoms, it’s important to get your vehicle’s codes scanned as soon as possible to prevent further damage. With the O’Reilly VeriScan code reading service, you can have your Check Engine, ABS, or transmission codes scanned for free to help you diagnose potential causes and complete your repair. If you’re uncomfortable making the repairs on your own, we would also be happy to recommend a local shop to help get your car back on the road.

O’Reilly Auto Parts’ FREE Store Services

Along with our free O’Reilly VeriScan Check Engine light testing, O’Reilly Auto Parts also provides several other free store services including alternator and starter testing, wiper blade installation, headlight bulb installation, and fluid and battery recycling. Stop by your local O’Reilly Auto Parts store today to learn more about our O’Reilly store services.

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