Can the Check Engine Light Burn Out?

Being that the check engine light probably won’t be used all that often in most cases, it’s unlikely that it will ever burn out. However, the check engine light uses a bulb like many other lights, so if the light is left on for long enough, there’s definitely a chance the bulb will burn out.

Check Engine Light Overview

The “check engine” light is a little bit of a misnomer, since it’s designed to turn on in the case of many types of equipment failure, not just engine-related failures. The check engine light is sometimes referred to as the “malfunction indicator lamp”, which is a somewhat more accurate description, but for the sake of clarity, we’ll just stick to calling it a check engine light.

The check engine light is pretty easy to notice; in almost every vehicle, the check engine light appears as a yellow or orange outline of an engine block. In many cases, the light will also have the words “check” or “check engine” within or under the outline of the engine, just so there’s no confusion about what the light is trying to tell you.

The check engine light is controlled by the powertrain control module (PCM), a computer in your car that monitors inputs from sensors located throughout the car. While cars these days tend to contain multiple computers, the PCM is one of the most important ones, as it monitors data related to performance and engine management.

Having a properly functioning check engine light is necessary, not just because it can help you determine if there is a mechanical fault with your car; you also need a working check engine light in order to pass an emissions test in most areas.

You’ll automatically fail an emissions test if your engine light is on, but if your light isn’t working at all, then this can also cause you to fail a test. 

What Problems Does the Check Engine Light Indicate?

As we’ve mentioned, a checked engine light doesn’t necessarily mean that something is wrong with the engine itself. The check engine light will come on for a wide range of issues, including problems with your fuel and exhaust systems.

There are several common issues that can cause a check engine light to come on, however. If your check engine light is indeed on, there’s a good chance that the cause is one of the following:

  • A loose gas cap-Believe it or not, your check engine light will turn on if you’ve failed to secure your gas cap correctly, if the seal on your gas cap has failed, or if your gas cap is missing entirely. 
  • A faulty mass airflow (MAF) sensor– The MAF sensor is a component of your car’s fuel injection system that monitors the amount of air coming into the engine. The MAF sensor sends this data to the PCM, which adjusts the amount of fuel being sent to the cylinders to maintain the correct air/fuel ratio.
  • A bad oxygen sensor-Oxygen sensors are similar to MAF sensors, except oxygen sensors monitor the level of oxygen in the engine’s exhaust. This also helps the engine adjust how much fuel is being burned for maximum efficiency.
  • Bad spark plugs/spark plug wires– Your spark plugs are, of course, used to ignite the air/fuel mixture in your engine’s cylinders, making them a vital component of the combustion process. If one of your spark plugs fails or the wire providing the spark plugs with power goes bad, this can trigger a check engine light.
  • A faulty catalytic converter-The catalytic converter is an important part of your exhaust system that reduces the amount of toxic gases produced from burning fuel. Catalytic converters can occasionally fail or break, causing your check engine light to illuminate.

These are just a few of the common reasons why your check engine light might be on. For the sake of space, we only covered a few, but there are other issues that can trigger a check engine light, including a bad solenoid, a bad fuel injector, or a faulty thermostat.

Fixing a Burned Out Check Engine Light

If you believe your check engine light has burned out and want to replace it yourself, the procedure is a little more difficult than replacing a headlight or taillight bulb. Replacing a check engine light, or any light in your dashboard cluster, almost always involves removing the trim panels from your dashboard.

Once you’ve done this, you’ll be able to get at the circuit board that controls all of the dashboard lights. The actual bulbs used for the dashboard lights can vary depending on what car you have; some bulbs attach to the circuit board via a twist socket, while others need to be soldered directly to the circuit board.

Unless you have some experience with electronics and you’re comfortable taking your dashboard apart yourself, we’d recommend that you take your car to a repair shop in order to replace your checked engine light.

Summary

Seeing a checked engine light in your car can certainly be a cause of anxiety, but you should also be concerned if your light isn’t working at all. If you live in an area that requires periodic emissions testing, a burned out check engine light can make you automatically fail a test.

The check engine light will also let you know if something is wrong with your car that you may not be aware of, so in any case, it’s a good idea to get your check engine light fixed quickly if you suspect that it may have burned out. 

Brian