Why Is My Check Engine Light On?

Check Engine Repair Shop in Canton

Check Engine Light Killian Automotive

When the instrument panel lights of your vehicle come on, it is normal to be apprehensive. In the case of the motor-shaped amber light known as Check Engine Light (CEL), the anxiety is higher. You might ask: What is wrong with my engine? Why is my check engine light on?

In this article, the specialists at Killian Automotive will help us answer these and other common questions related to this intriguing warning light.

What is a check engine light?

A steady check engine light indicates that your car’s Electronic Control Module (ECM) suspects an issue with one or more of its subsystems. In other words, it is a warning similar to the battery light or the oil light, a signal designed to get your attention. Some manufacturers prefer to call this light Service Engine Soon (SES) or Malfunction Indicator Light (MIL) in an attempt to make it clear that you should not ignore it.

What does it mean if my service engine light is flashing/blinking?

A flashing or blinking check engine light usually means that your ECM has determined a severe issue needing immediate attention. In most cases, ignoring this warning may lead to a costly repair. For instance, if the ECM detects an engine misfire problem, it will command the CEL light to flash to warn you that using your car in this condition will cause serious damage to the catalytic converter.

What happens when the engine light turns on?

When the ECM lights up, the engine light comes on to tell you something unusual has happened. As a first measure, the ECM stores one or more Data Trouble Codes (DTCs) related to the incident in its memory. Second, depending on the failure, the electronic control module may activate an emergency mode known as “limp mode” to prevent the engine and transmission from becoming damaged.

Can I solve the problem with a code reader?

The short answer is, probably not. Modern vehicles come equipped with sophisticated systems consisting of dozens of sensors and electronic components. Sometimes a loose wire or an electrical connector that gets wet can trigger the check engine light. Even a loose gas cap can make the ECM light turn on. When that happens, clearing the data trouble codes from the ECM memory usually fixes the problem, at least temporarily.

However, if the problem wasn’t a loose gas cap, it is likely the light will turn on again. While it is true that the information provided by generic OBD2 code readers is invaluable to narrow down the possible cause of the failure, it is also true that DTCs could be misleading, especially to unexperienced DIY enthusiasts or mechanics. These codes do not lead a mechanic directly to the problem. For example, something as simple as a faulty connection or a burned wire could trigger an oxygen sensor DTC. Replacing the sensor will not solve the problem. That is why in most cases it is recommended that an experienced automotive technician perform a thorough diagnostic process to determine the true cause behind the check engine light.

Is it safe to drive with the check engine light on?

There is no simple answer to that question. For example, driving your vehicle when there is a problem with the Electronic Throttle Control (ETC) would pose a risk to your safety, as you could lose control over the vehicle’s acceleration. On the other hand, the only consequence of driving with a bad ambient temperature sensor would be reduced fuel mileage. In both cases, the check engine light will turn on. Keep in mind that the engine light is just a warning; it’s up to you what to do next.

What should you do when the check engine light comes on?

Hopefully, at this point, you will agree that ignoring the check engine light is not a good idea. The consequences of driving your vehicle with this light on are unpredictable. As already explained, the engine light could be caused by a minor fault (such as a loose gas cap) or a severe failure related to the engine or transmission. In either case, the best approach is to find a trustworthy automotive repair shop near you to determine what is causing the issue.

At Killian Automotive, we have over 24 years of experience in diagnosing Domestic, Asian, and European vehicles. Moreover, our ASE Certified Technicians use only the most recent scan tools to pinpoint the problem causing the check engine light to turn on. No guesswork, no unnecessary repairs.

What are you waiting for? Does your car have the check engine light on? If so, call us at 770-345-5873 or contact us to schedule an appointment. Our staff is happy to help!