Many drivers are familiar with the situation when the Check Engine indicator lights up on the dashboard while driving. This signal often appears unexpectedly and can scare, especially beginners. In this article, we will tell you how to find out the cause of the icon lighting up, what it means, and what steps to take if the light does not go out.

What does the check in a car symbolize

The Check Engine indicator, which drivers often simply call the "check," is a malfunction lamp for the power unit and related components. It lights up on the dashboard, signaling a recorded error in the car's operation. The lamp can burn constantly or blink, and the nature of the glow helps assess the seriousness of the breakdown.

Main reasons for a lit check

Why does the indicator activate? There are quite a few factors provoking this, from harmless to very serious. Among them:
  1. Malfunctions in the oxygen controller (lambda probe)
    This is related to incorrect formation of the fuel-air mixture or erroneous data from the sensor.
  2. Refueling with low-quality fuel
    This occurs due to a mismatch in the octane number or the presence of foreign additives.
  3. Failure of the catalytic converter
    A clogged or damaged catalyst disrupts the operation of the exhaust system.
  4. Failures in the ignition system
    Worn spark plugs, faulty coils, or damaged wiring.
  5. Breakdown of the mass air flow sensor (MAF)
    With such a malfunction, the engine starts to run intermittently, and the check lights up.
  6. Unscrewed fuel tank neck
    Strange as it may seem, the system is sensitive to gasoline vapor leaks.

pochemu-zagorelsya-check-engine.jpg

Ways to determine the cause

How to understand why the check lit up? Several diagnostic options are available:

1. Using an OBD2 scanner

This is the main and most reliable method. The OBD-II connector is present in cars produced in the 2000s and later.
- The scanner connects to the port,
- The fault code is read,
- Based on the code, the cause is established.
Inexpensive scanner models cost between 10-30 dollars; you can also use smartphone applications (for example, Torque or Car Scanner).

2. Contacting a service center

If there is no scanner, it is worth going to a service station. There, professional equipment is used to quickly find out why the check is lit and determine the necessary actions.

3. Self-inspection and analysis of symptoms

Assess the signs:
- Does the engine run intermittently or stall?
- Has fuel consumption increased?
- Are there jerks when accelerating?
Such observations can hint at the cause.

What a blinking check indicates

Blinking of the indicator indicates a serious breakdown, for example, misfires that can lead to damage to the catalyst. In such a situation, you need to:
  • Immediately reduce speed,
  • Avoid sharp accelerations,
  • Visit a service station as soon as possible.

The check is lit, but the car's behavior has not changed

This happens quite often: the lamp is active, but it does not affect driving qualities. The reasons may be:
  • A one-time glitch in the sensor operation,
  • An error caused by insufficient oil level,
  • Consequences of short-term detonation.
However, you should not neglect the signal, even if the car drives as usual. A small error can grow into a serious malfunction.

How to remove the check indicator

After fixing the problem, you can reset the check in several ways:
  1. Independently — via an OBD2 scanner.
  2. By removing the negative battery terminal for 10-15 minutes (not for all models).
  3. Just wait — on some cars, the indicator goes out on its own after 3-5 successful starts if the malfunction no longer appears.
Now it is clear how to find out why the check lights up. The key method is to connect an OBD2 scanner and decode the error code. There are many reasons for the lamp to activate: from spark plugs and fuel to sensors and the catalyst. The main thing is not to leave the signal unattended and to deal with diagnostics in time.