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Check Engine Light

Aug 28, 2019

Why Your Check Engine Light May Be On

You're driving down the road to your next destination and the little yellow check engine light is illuminated on your vehicle's dashboard. What does this mean? You may be wondering if you should pull over immediately, drive to your closest Sullivan Tire and Auto Service to have it inspected, or just wait until it turns off. The check engine light doesn't mean there is one particular issue wrong with your vehicle, but is an indicator that there is an issue with your vehicle that needs to be addressed and diagnosed as soon as possible. It could indicate anything from your gas cap being loose to a serious engine problem.

What does the Check Engine Light Mean?

The check engine light is connected to your vehicle's onboard diagnostics system (OBD) which is a computer system within your vehicle that monitors your vehicle's various systems, such as the ignition system or engine performance, and can detect malfunctions throughout your vehicle. When the check engine light turns on, that's the OBD system giving you an early warning sign of a potentially failing component in your vehicle. To diagnose why a check engine comes up, a qualified technician will connect a scan tool to your vehicles OBD system and it will communicate to the scan tool, in the form of special codes, that will indicate where the problem lies.

In later model vehicles, if the check engine light is blinking, this means there may be a more serious issue that needs to be looked into immediately. If the light remains constant, the problem is not an emergency but an appointment will still need to be made to diagnose the problem.

What to Do

  • Slow Down
    • If your check engine light is blinking, slow your vehicle down to reduce stress.
    • If you're towing an extra load, such as a camper or trailer, keep in mind this is adding additional stress to the vehicle.
  • Inspect Your Vehicle for Immediate Problems
    • Are all of the gauges on the dashboard reading normal or, for example, is the dashboard gauge indicating that your vehicle is overheating?
    • If you do see immediate problems, pull over and do not drive the vehicle. Have it towed to the nearest Sullivan Tire and Auto Service to be diagnosed. Continuous driving under these conditions could cause serious damage to your vehicle and leave you with additional costly repairs or leave the vehicle irreparable. 
  • Check your Gas Cap
    • Sometimes the check engine light turns on because the gas cap on your vehicle isn't tight enough. You may have to drive your vehicle around several times before the light resets itself. 
  • Have Your Vehicle Diagnosed
    • Make an appointment with your local Sullivan Tire and Auto Service to have one of our trained technicians run a computer diagnostics test on your vehicle. They will be able to accurately read the codes your OBD is outputting to diagnose the problem. 
    • There are certainly devices that you can buy to tap into your OBD system yourself to pull a code, and there are companies advertising that they will pull a code for you for free, but this does not necessarily tell you what is wrong with the vehicle. It will still have to be properly diagnosed to determine the real problem. 


*These instructions are suggestions and standard practices for an emergency scenario. Sullivan Tire and Auto Service is not to be held liable or responsible in case of an accident or road emergency.