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My Check Engine Light Won’t Turn Off

You will find hundreds of websites with guides on how to force a reset of your check engine light to turn it off, but we here at Scotty’s Automotive Service don’t recommend you do that. There’s a reason why the light came on and refuses to turn off, and this reason could be a serious problem in your vehicle’s exhaust system or an ignition or transmission problem. Let’s talk about the light and why it comes when you start your car and while you’re driving.

Check Engine Light Basics

Every system in your automobile has a computer sensor that monitors the system’s activity. These sensors report system activity to the Engine Control Module (ECM). If there is a problem, the sensor will send an alert to the ECM and the ECM will turn on a dashboard warning light to alert you of trouble. Some problems have their own warning light, such as low oil or fuel. If there isn’t a light that covers the reported problem, the ECM will turn on the check engine light.

False Alarms

Many of these web pages that tell you how to reset your check engine light will state that the light comes on for no reason. This is true on rare occasions, but it’s important to understand that this doesn’t happen as frequently as people think it does. In fact, a 2019 study on vehicle diagnostic testing revealed hidden issues in nearly all of the automobiles tested, many of which had a check engine light warning. Even if the check engine light is malfunctioning, it’s important to confirm the false alarm.

Reasons Why The Light Comes On

Think about your vehicle’s dashboard and all of the lights it has, and then think about all of the vehicle systems not included in those lights. When you do this, you realize how important this warning light is. There are many reasons why the ECM will turn on a light, and they include

  • Catalytic converter failure that can lead to carbon monoxide poisoning
  • Fuel system problems including a loose fuel cap and fuel evaporation
  • A failing mass airflow sensor that can affect the air/fuel mixture
  • A failing oxygen sensor that can misreport your vehicle’s exhaust
  • Spark plug problems such as misfiring, wear, and failure
  • Transmission problems that might include gear wear and failure
  • Electrical problems that could include surges and fire danger

We know this sounds drastic, but the check engine light will come on in these circumstances. It could be that the light is a false alarm, but don’t take chances. Bring your vehicle into Scotty’s Automotive Service, LLC, in Montague, NJ, for a diagnostic check to make sure everything is okay.

Photo by BDoty from Getty Images Signature via Canva Pro
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