Demystifying the Engine Error Codes: All About Engine Error Codes Explained

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Home ยป Demystifying the Engine Error Codes: All About Engine Error Codes Explained


As a car owner, there’s nothing more frustrating than seeing your check engine light come on. And while the light itself can be alarming, what’s even more concerning is the engine error code that comes with it. Engine error codes can be intimidating, especially if you’re not familiar with them. But understanding what they mean and how to fix them is essential to keep your car running smoothly.

In this article, we’ll explore everything you need to know about engine error codes. We’ll cover what they are, what causes them, and how to read and interpret them. We’ll also provide some tips on how to fix common engine error codes, so you can get your car back on the road.

What are engine error codes?

Engine error codes are diagnostic codes that are stored in your car’s onboard computer. When your car’s computer detects an issue with one of its components, it will log a specific code that corresponds to the problem. The code is then stored in the car’s memory until it’s cleared or fixed.

There are hundreds of engine error codes, and each one corresponds to a specific problem with a particular component of your car. Some common engine error codes include:

  • P0300: Random/Multiple Cylinder Misfire Detected
  • P0420: Catalyst System Efficiency Below Threshold
  • P0171: System Too Lean (Bank 1)
  • P0128: Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)

Each code is made up of a combination of letters and numbers, which indicate the specific problem and the affected component.

What causes engine error codes?

There are many different things that can cause engine error codes to appear. Some common causes include:

  • A loose or damaged gas cap
  • A malfunctioning oxygen sensor
  • A faulty mass airflow sensor
  • A damaged catalytic converter
  • A worn-out spark plug or ignition coil
  • A malfunctioning EGR valve

These are just a few examples of the many things that can trigger an engine error code. In many cases, the cause of the error code can be difficult to diagnose, which is why it’s essential to take your car to a qualified mechanic for a proper diagnosis.

How to read engine error codes?

Reading engine error codes is relatively straightforward. To do so, you’ll need an OBD-II scanner, which is a tool that can read the diagnostic codes stored in your car’s computer.

Here’s how to read engine error codes:

  1. Locate your car’s OBD-II port. This is usually located under the dashboard on the driver’s side of the car.
  2. Plug your OBD-II scanner into the port.
  3. Turn your car’s ignition to the “On” position, but don’t start the engine.
  4. Follow the instructions that came with your scanner to read the error codes.

Once you’ve read the error codes, you’ll be able to see which component is causing the issue. You can then take this information to a mechanic to get it fixed.


In conclusion, engine error codes can be a scary and confusing aspect of car ownership. However, understanding what they are, what causes them, and how to read and interpret them can help you take better care of your car and avoid costly repairs. While there are many different types of engine error codes, they all serve the same purpose: to help diagnose problems with your car’s components. By taking the time to learn about engine error codes and how to fix them, you can keep your car running smoothly for years to come. Remember, when in doubt, always consult a qualified mechanic for a proper diagnosis and repair.