Check Engine: A scary light or a minor error?

When the Check Engine light suddenly comes on the dashboard, even a calm driver starts to get nervous. This light literally says: "Check the engine," but it is not immediately clear what exactly to check. Sometimes the reason is trivial, sometimes it is extremely serious. Let's figure out what this signal means, when you can continue driving, and when it is better to call a tow truck immediately.

What Check Engine Really Means

The indicator lights up when the electronic control unit detects an error in the engine or systems directly related to it. It is important to understand: one light - dozens of possible reasons. Even expensive cars with advanced electronics like BMW, Audi or Porsche do not "explain" the essence of the problem to the driver without diagnostics.

The error can be:

temporary;
periodic;
permanent;
critical.

The light may be on steadily, flashing, or appearing only occasionally. You can't ignore it, but you shouldn't panic either: in most cases, the car remains on the move.

Is it possible to continue driving

If the Check Engine light comes on while driving or does not turn off after starting, you can drive, but subject to certain conditions. It is strictly forbidden to drive further if:

the car has lost power sharply;
the engine has entered emergency mode;
the lamp is flashing constantly;
the engine is running intermittently, vibrations are felt;
the oil, overheating or catalyst indicators light up at the same time.

In such cases, it is better to stop immediately, turn off the engine and call a tow truck. If the car behaves stably, it is allowed to carefully drive to the service, without postponing the diagnostics.

The most common causes of Check Engine

1. Fuel problems

The most common and at the same time the most harmless option. Poor-quality gasoline or diesel causes detonation, uneven engine operation and loss of traction.

What can be done:

refuel with high-quality fuel to "dilute" the bad one;
watch - sometimes the error disappears by itself.

A separate nuance is the gas tank cap. A loosely tightened or cracked cap causes depressurization of the system, and the electronics immediately signal an error. Check it first.

2. Low oil level

If the Check Engine light comes on together with the oil pressure indicator, you cannot drive. You need to stop immediately and check the level.

With a lack of oil:

add strictly the same oil that was used previously;
after that, be sure to go to the service - a leak or increased consumption is possible.

3. Fuel pump

A faulty pump makes itself felt immediately: the car loses traction, behaves unstably, may stall. If it fails completely, the car will simply stop. There are no options here - only service, sometimes with a tow truck.

4. Fuel injectors

Problems with injectors manifest themselves in a complex way:

fuel consumption is growing;
power is falling;
обороты плавают;
jerks appear during acceleration.

If the Check Engine light comes on at the same time, the malfunction has already started.

5. Spark plugs

Misfires, jerks when starting and accelerating are a classic symptom of worn spark plugs. The lamp in this case literally says: "Change consumables".

Critical malfunctions: lambda probe and catalyst

One of the most unpleasant reasons is malfunctions in the oxygen sensor or catalyst. The lambda probe monitors the composition of the exhaust and transmits data to the ECU.

In case of its malfunction:

fuel consumption is growing;
power is falling;
the emission of harmful substances increases.

Worst of all, a faulty sensor gradually kills the catalyst, and replacing it is already a completely different money. Such an error is determined only by computer diagnostics.

Other possible reasons

In practice, there are many more reasons for the appearance of Check Engine. Among them:

failure of various engine sensors;
wiring damage;
failures in the ignition system;
problems with air supply.

It is useless to guess here without diagnostics.

Is it possible to reset Check Engine yourself

Yes, there are several ways to temporarily remove the error without a scanner.

Method 1:

Remove the negative terminal of the battery
Wait 30 seconds
Install the terminal back

Method 2 (if it didn't help):

Remove the negative and positive terminals
Turn on the light
Connect the terminals to each other for 15 seconds
Connect back (first plus, then minus)

If after that there is an all-wheel drive error, turn the steering wheel all the way to the left and right - the system is often reset.

Important: resetting the error does not cure the malfunction. This is only a temporary measure to get to the service. If the problem is serious, Check Engine will light up again.