Solving the Mystery of the Check Engine Light

Check Engine Light

Few vehicle issues cause that sinking feeling in the stomach the way an illuminated check engine light does. Out of all the dashboard warning lights, the check engine light is often the biggest mystery to most drivers. Here’s a look at what it means when your check engine light is on and why you shouldn’t ignore it.

What’s the Purpose of the Check Engine Light?

Most of your vehicle’s engine functions are controlled by the engine control computer. This computer can adjust many of the engine’s parameters to compensate for environmental conditions, engine conditions, and even driving habits.

The engine control computer relies on a network of sensors to provide data to base these adjustments on. Each sensor has a proper operating range; when one of the sensors is out of range, the computer runs some tests, which may cause the check engine light to come on. It will then try to make adjustments to compensate for the readings, and if it’s successful, it will turn the check engine light off.

In addition to turning the light on, the computer will store a trouble code in its memory, identifying the source of the problem. We can then read the code using diagnostic equipment, which points us to what the issue is.

Is Your Check Engine Light Flashing or Constantly Illuminated?

One thing to pay attention to when your check engine light comes on is whether the light is flashing or constantly illuminated.

If the light is flashing, this means there’s an issue occurring that could cause severe damage to the engine, catalytic converter, or other components. This isn’t something to ignore—it should be addressed right away. You should also avoid traveling at highway speeds or towing or hauling heavy loads. Take it easy on your way over to the shop or have your vehicle towed if driving it there makes you uncomfortable.

If the light is glowing steadily, you should keep an eye on it for a day or two. If you recently filled your gas tank, check that the gas cap is on tightly; a loose gas cap can cause the light to turn on. If this solves the problem, great! If not, and the light stays on for more than a day or so, you should schedule an appointment for diagnostics.

Common Issues That Trigger the Check Engine Light

Many issues can cause the check engine light to turn on, but some of the most common reasons include:

  • Oxygen sensor failure
  • A loose or faulty gas cap
  • Catalytic converter failure
  • Spark plug or ignition coil issues
  • Bad spark plug wires
  • Mass airflow sensor failure
  • Issues with an aftermarket alarm system
  • Vacuum leaks
  • Exhaust gas recirculation valve failure

If you’ve noticed anything unusual happening with your vehicle, such as loss of power, stalling, or other performance issues, let your service advisor know. This can help us pinpoint the problem quickly and get you back on the road sooner!

Check Engine Light Diagnostics & Repair

Whether it’s flashing or steady, if the check engine light is on, it needs to be addressed. Waiting too long to have your vehicle checked out can result in damage to components and a more expensive repair.

EuroCar Service offers complete diagnostics and repairs for all European makes and models, including Audi, BMW, Mercedes, Land Rover, Mini Cooper, Jaguar, Smart Car, Fiat, Volkswagen, Saab, and Volvo. Our ASE-certified technicians use the latest diagnostic equipment and repair procedures to ensure the issues are repaired properly the first time. Contact us today at (206) 527-8828 or request an appointment online.