Help! My Check Engine Light Is On!

The dreaded Check Engine light always seems to appear on your dashboard at the worst possible time. It’s designed to inform you when it’s time to take a trip to the mechanic, but many drivers don’t find it to be particularly helpful because it seemingly doesn’t offer any more information than that. Let’s see if we can ease your mind with a little expertise.

The concern the light is indicating may be something simple, with an easy and inexpensive fix, or it may be a sign that a very expensive repair job is on the horizon. There are many Check Engine light meanings, and some cars even have multiple lights that indicate different issues. It’s not always easy to decipher what your car is trying to tell you when that infamous light comes on, but when you combine it with other clues, it can help you to determine what steps to take next.

The Lights on Your Dashboard

Depending on the make and model of your vehicle, it most likely has multiple lights on the dashboard that will light up to indicate different information about your vehicle. These will look different depending on the brand and model, so take time to familiarize yourself with your vehicle’s manual. It will contain the basic information regarding each of the lights on your dashboard. Often, they will simply indicate what they are for with a word or two of text, such as “service” or “check.”

The Check Engine light comes on when there is an issue that requires your attention, whether it’s major or minor. Note, however, that it is not the same as the Maintenance Required light, which simply indicates that your car is in need of an oil change or other routine maintenance issue. The Check Engine light, on the other hand, indicates that something out of the ordinary has occurred and may require specialized maintenance from your trusted mechanic.

Some vehicles, such as the hybrid cars manufactured by Toyota, also have dashboard lights that indicate if there is a problem with the hybrid battery. The widely feared “red triangle of death,” for example, indicates a problem not with the engine but with the larger of the vehicle’s two electric batteries (for this reason, Toyota drivers should bring their vehicles to a certified service department like the one at Beaverton Toyota).

Is the Light Solid or Blinking?

In most vehicles, the Check Engine light has two different settings: solid or blinking. In most vehicles, a solid Check Engine light indicates a non-emergency issue, such as a faulty electrical connection or a problem with a spark plug. If it is flashing, however, it may indicate a more serious problem, such as a damaged catalytic converter. The catalytic converter may even be missing entirely, as theft of this critical element is a major issue for vehicle owners.


Whether the light is blinking or not won’t tell you what, if anything, is wrong with your engine. You’re going to need more information. Modern cars are fitted with diagnostic computers that are connected to sensors installed within the engines. These sensors are what signal the Check Engine lights to switch on when they detect something out of the ordinary. Of course, “out of the ordinary” is a broad category, so you should see your mechanic accordingly.

If your Check Engine light is flashing, consider it an emergency; call for a tow and head straight for the mechanic rather than attempting to drive when your car is indicating a more serious problem. If the Check Engine light is solid, it’s a good idea to check a few things on your vehicle or pay your mechanic a visit as soon as convenient.

Finding Out What’s Wrong

As we’ve established, the Check Engine light meaning can vary a great deal and is often a sign that you should have it looked at. However, in some cases, the problem will be minor enough that you can fix it yourself. Take note of exactly when the light came on, as this can serve as a vital clue to the issue that is troubling your vehicle. Did it happen immediately after getting gas? Then it may be as simple as some spilled gasoline that has seeped outside of the tank or a loose gas cap. Try tightening the cap to rule out this common issue before continuing to look for other problems with the vehicle.

A solid Check Engine light also frequently indicates faulty electrical connections or damaged or dirty spark plugs. If this is the case, there may be other signs of the problem as well. For example, if the car is struggling to turn over or seems to be experiencing a rough idle, an electrical or spark plug issue may be to blame. In either case, bring your car to a trusted mechanic and request a diagnostic.

Another common reason for a solid Check Engine light is a faulty mass air flow sensor (MAF). This device measures exactly how much air is allowed to enter your engine, which is important because airflow is a critical element of gasoline combustion. If the sensor is faulty, not only will it cause the Check Engine light to come on, but it will also cause issues with the vehicle’s ability to turn over. In the worst-case scenario, the car will not start at all.

Sometimes the issue that is causing the Check Engine light to turn on will not be so obvious; in this case, you may be able to determine the problem with a specialized onboard diagnostic (OBD) scanner. By plugging it into the vehicle, this scanner will interface with the vehicle’s onboard computer and indicate the problem with one of a series of diagnostic codes. Of course, you may not have easy access to an OBD scanner. Even if you do, it’s likely whatever the problem is will need to be addressed by a professional mechanic.

When in Doubt – Visit a Mechanic

One thing you should never do if your Check Engine light comes on is completely ignore it. Whether it’s a minor concern or a full-blown problem, your vehicle’s Check Engine light is telling you to pay attention. If you tighten your gas cap and the light doesn’t go out, or if you are experiencing other issues in addition to your Check Engine light, see a trusted mechanic. An expert like the service pros at Beaverton Toyota will have you back on the road and driving safely in no time.