“Check” icon in the car: what it looks like, what it means and when it lights up

The translation of the expression “check engine” in Russian literally sounds like “check the engine.” The “check” icon is on the dashboard of most modern cars, but its meaning remains unclear to many. Therefore, if this icon is yellow or orange engine icon - appears and does not disappear (or simply blinks), an inexperienced driver has a natural question: “what does this mean?” Next, we’ll try to find out the reasons why the check engine light came on on the dashboard of your car, as well as how to get rid of it.

Initially, this light indicated problems with the carburetor, but now that cars are equipped with full-fledged on-board computers, the message may indicate various malfunctions. For example, a “check engine” error may indicate problems with the quality of the air-fuel mixture or ignition faults, as well as many other things. Messages can be caused by both minor and critical failures.

Thus, when the “check engine” light is on, it is only clear that the ECU has detected a malfunction in one of the car’s systems. Only diagnostics can give a complete picture. Next, we will look at the main reasons why the check engine light is on and what needs to be done about it.

What does it look like

An illuminated check engine light on a vehicle looks like a yellow or red “video camera” without an exclamation point, with the words Check Engine displayed inside or next to it. The indicator lights up on the car's dashboard (on the display behind the steering wheel). A photo of a picture with a receipt icon in a car is presented below.

Check badge in the car

The yellow “Check Engine” icon means that the car owner needs to independently change something in the car control system or take the car to a service station.

A red indicator may indicate a serious breakdown. Driving by car is strictly not recommended. The car needs to be taken to the service station urgently.

If the engine light is on in the car, then there are definitely the following faults:

• low-quality gasoline or other fuel is poured into the tank;
• spark plugs have failed;
• the integrity of the ignition system coil winding is damaged;
• there is a short circuit in the engine;
• The residual oxygen sensor (lambda probe) stopped working;
• the injectors are clogged;
• the catalyst does not work.

The Check Engine icon only blinks intermittently in the following situations:

• When the engine triples (not all the fuel burns). The check sign in the car lights up when a spark is missed. Unburnt fuel is discharged through the exhaust manifold.
• In case of critical wear of the catalytic converter. As a result, the car cannot be used.
• If the engine ECU fails.

The exact cause of a car breakdown can only be found out by diagnosing the ECU with an OBD 2 scanner or at a service station.

Refueling with low-quality fuel

If the check engine light comes on immediately after refueling, the reasons almost certainly lie in the fact that the fuel poured in is of poor quality.

We are not talking about situations where the octane number is reduced by one level, for example, instead of 95 gasoline, 92 gasoline is poured. The difference between them is not that significant. But refueling with 92 instead of 98, clogging gasoline with a large number of impurities or paraffin can lead to an error.

In such cases, the behavior of the car almost always changes. The engine's power drops sharply, it makes unusual noise, and the dynamics are not enough even for relatively quiet acceleration. There are two ways to correct the situation:

• By adding a large amount of good fuel to the tank, a step above what the manufacturer recommended. This means that if you usually fill up with 98-grade gasoline, but mistakenly filled up with 92-grade gasoline, then AI-100 will help correct the situation.
• By adding a special additive to the tank, the so-called octane corrector.

Important to note: If the check engine button does not go off 5-10 minutes after new gasoline or additive was added, immediately go to the service center. You can't do anything else on your own.

What does it mean

Check Engine is translated from English as “check the motor (engine).” The error code is indicated as follows: P0102… P0616.

The first letter of the error code identifies one of the car systems in which the breakdown occurred. There can be 4 codes in total:

• P - gearbox and/or engine;
• U - CAN bus;
• C - chassis;
• B - airbags, electric windows, central locking.

The second character after the letter indicates the type of error. The breakdown can be general (the same for all OBD II engines) or specific (for a specific car).

When the check icon appears

The second character of the error code is indicated by the following numbers:

• 0 - OBD 2 code;
• 1, 2 — manufacturer code;
• 3 - Reserved SAE (reserve).

The third character of the error code is the car subsystem where the failure occurred. The following numbers may appear on the receipt icon in your car:

• 1, 2 - injector circuit, fuel pump, fuel tank or air supply system;
• 3 - ignition system;
• 4 — auxiliary system (control);
• 5 — car speed, idle;
• 6 - ECU and its external circuits;
• 7, 8 — gearbox;
• 9, 10 - reserve.

The fourth and fifth characters of the error code indicate its serial number.

How to redeem a badge

The Check Engine icon remains on the vehicle's dashboard as long as there are still error codes in the OBD system's memory. After the fault is repaired, the codes are erased using a diagnostic tool. You can also extinguish the check icon in the car by disconnecting the terminals from the battery (for 3-5 minutes).

The easiest way in this case is to use a personal scanner. There are quite a lot of similar devices on the market, and an inexpensive car scanner will cost less than one visit to a service station. For example, we can recommend the multi-brand diagnostic scanner Rokodil ScanX.

The advantage of this model is that it is compatible with most cars produced in 1993 with an ODB2 connector. The scanner connects to any iOS, Android or Windows device via Bluetooth. In addition to resetting errors with the scanner, you can carry out a full diagnosis of the car and fix the problem yourself. After diagnostics, the device will indicate the problematic element and display its error code with a detailed description. We will consider the most common error codes below.

Table of the most common error codes

To find out the error code, you need to do the following:

1. Turn off the car engine.
2. Look under the steering wheel and find the diagnostic connector.
3. Install the OBD 2 scanner into the found connector. If everything is done correctly, the indicator on the adapter will light up.
4. Pick up your smartphone and open Google Play Store.
5. Download, install and run the Torque program.
6. Open “Settings” on your phone, select the Bluetooth tab and find the Aut-Tech scanner.
7. In the window that appears, you must enter the password - 1234 (1111, 1234, 0000, 123456) and click on “OK”. The inscription “Authorized” will appear in the list.
8. Launch the Torque program.
9. On the smartphone screen, click on the button with a gear - this is “Settings” (or on the button on the phone body).
10. In the menu that appears, select “Settings”. In it you need to open the Connection section. Bluetooth (Wi-Fi) must be installed here.
11. Select the Device section. In the list, click on the Aut-Tech scanner.
12. Exit to the Torque program menu and click on Check Fault Codes. The error log will open.
13. Click on the search button (in the form of a magnifying glass). An error code will be displayed on the screen.

An overview table of common error codes with explanations is presented below.

Error Code Table

Once the error code has been deciphered, you can safely begin troubleshooting the problem yourself. If serious damage is detected, you must take your car to a service station.

In what situations can you reset errors yourself?

If the check icon is on in the car, then it is not necessary to immediately contact the service station. You can reset error codes yourself in the following situations:

• when refueling your car with low quality gasoline;
• if the car breakdown occurred due to a faulty fuel pump and its filter;
• in case of nozzle clogging;
• in case of failure of the ignition system;
• if the air supply system is broken.

You can also extinguish the “Check Engine” icon yourself if you have problems with car wiring, sensors and ECUs.

When filling the gas tank with low-quality fuel

Most often, the “Check Engine” icon lights up due to the presence of low quality fuel in the gas tank. After all, “diluted” gasoline is available at many gas stations.

Low quality gasoline clogs the fuel line and its parts. As a result, a malfunction such as tripping appears (the engine constantly stalls).

Refueling with low-quality fuel

To remove tripping, you need to drain gasoline (DF) from the entire system. Moreover, you will have to not only open the gas tank, but also remove it and wash it.

If the fuel pump and its filter are faulty

The “Check Engine” icon may also turn on if the fuel pump and its filter are faulty. To check the functionality of the pump, you need to stop the car and listen to the sounds of the engine running.

Everything is fine with the fuel pump if you hear a smooth hum (without clicking or pauses). If extraneous sounds are heard, then the pump must be removed and washed from the inside. You also need to clean the filter.

It would also be a good idea to check the pressure in the fuel rail. It should be equal to at least 3 atmospheres. If the pressure in the fuel rail is below 3 atm, you need to replace (clean) the filter or replace the old fuel pump with a new one.

If the injectors are clogged

If low-quality gasoline (DF) is poured into the gas tank, then over time the injectors become clogged. As a result, the engine begins to work intermittently.

To clear clogged injectors, you need to do the following:

1. Remove the injectors and disassemble them.
2. Remove the nozzles.
3. Install the nozzles into the washing stand.
4. Check their performance by applying different pressures.

As a result, the faulty nozzle is quickly cleared of debris. It can also be replaced with a new one.

Ignition system is faulty

The “Check Engine” icon may also indicate the failure of one or more spark plugs. To troubleshoot the problem, you need to do the following:

1. Carefully inspect the spark plugs.
2. Remove carbon deposits (if any).
3. Replace spark plugs if they are faulty.

Carbon deposits on spark plugs

Service station specialists advise changing not just one spark plug, but the entire set at once. This way you can avoid possible problems in the ignition system. Timely replacement of spark plugs is the key to the correct operation of the car engine and catalytic converter.

The air supply system is broken

The Check Engine icon also lights up if the throttle valve is faulty (clogged). To fix the problem, you will have to remove the throttle and clean it.

Service station specialists recommend cleaning the throttle valve using a specialized product (for example, Liqui Moly DrosselKlappen-Reiniger). But you can also use WD-40, acetone or carburetor cleaner.

Together with the throttle valve, the air filter pipe is also cleaned from blockages. If the air supply system is broken, the following signs of malfunction will appear in the car:

1. Increased consumption of diesel fuel (gasoline) and the level of carbon dioxide in the exhaust.
2. Reduced ride quality.
3. Reduced engine power.

If the air supply system malfunctions, poor acceleration dynamics are also observed. And in winter the car starts every other time. Malfunctions also appear due to improper installation of the filter when replacing it, or if it has not been replaced with a new one for a long time.

If you continue to drive a car with a faulty air supply system, then over the course of several months the engine will “eat” more and more gasoline (DF). The car owner needs to take his car to a service station as soon as possible or fix the problem himself.

If there are problems with wiring, sensors and ECU

More often, the “Check Engine” icon lights up on the car’s dashboard when the ECU fails or when the engine wiring is faulty. One of the sensors may also break.

After connecting the OBD 2 diagnostic adapter to the car dashboard, an error code will appear on your smartphone. After decoding, you need to find the broken sensor and check it with a multimeter. If there is no signal, the meter must be replaced.

Diagnosis of wiring faults is carried out in a similar way. Only after deciphering the error code is the wire ringing done. As a result, it will become clear which section of the wiring needs to be repaired.

Car wiring diagnostics

If a wiring fault is detected, service station specialists advise immediately changing the wire in the area where there is damage. After all, car owners often simply strip and insulate the damaged cable.

The Check Engine light may also come on if the engine ECU is faulty. Installing new software on the car control unit will quickly solve the problem.

The catalyst is clogged

The check icon may also light up due to damage to the exhaust system. In addition to the sign, such a problem may be indicated by a changed color of the exhaust gases or a decrease in dynamics while driving. Over time, the situation will worsen.

The throughput will decrease, and the pressure between the block head and the converter, on the contrary, will increase.

Ultimately, the power unit will become clogged with ceramic particles every day, the cylinders will become clogged, and oil will leak in huge quantities. In order not to let the problem become critical, it is better to seek help from a specialist right away.

Is it possible to drive a car if the Check Engine light is on on the dashboard?

If the Check Engine light suddenly lights up in your car, you first need to insert the key into the ignition and start the car. Let the car idle for 3-5 minutes.

After 3-5 minutes, you need to increase the engine speed. If no extraneous sounds (clicks) are heard or there are no pauses, then you can start moving towards the service station (first at 20-30 km/h).

If the car service is far away, you should do the following:

1. Stop the car.
2. Turn off the engine.
3. Open the hood.
4. Remove the negative terminal from the battery.

If, after re-igniting the engine, the Torque auto program does not show an error code, then the malfunction can be considered accidental. However, the car owner should contact the service station for advice.

The Check Engine light may come on while driving. If the icon appears after refueling at a gas station, then in most cases the fuel is clearly at fault.

After a breakdown occurs, it is recommended to drive to a branded gas station and fill the gas tank with high-quality fuel (gasoline). As the car moves further, there should be no strong dips, twitching or sudden decrease in engine power. Otherwise, the car owner should get to the nearest service station as quickly as possible (on his own or by calling a tow truck).

Oil level drop

An error in engine operation can also occur due to something as trivial as a lack of lubrication. Usually this option is built into expensive foreign cars and is almost always accompanied by another icon - overheating.

Moreover, they do not light up immediately after ignition, but only after a few minutes. Check the amount of oil fluid with a dipstick and, if necessary, add it to eliminate the error yourself.

It is important to note: If the situation repeats with a small frequency, you will still have to call the master. Because oil consumption can be a symptom of other “diseases” of the engine or car.

What can result from untimely repair and diagnostics of a car engine?

If the breakdown is not promptly repaired after the Check Engine light comes on, the following consequences are possible:

• Troubleshooting, engine shutdown.
• Systems failure.
• Increased consumption of diesel fuel (gasoline).
• Transmission overheating.
• Cylinder head deformation.
• ECU block failure. Its malfunction often leads to incorrect operation of car systems.

If the Check Engine light on the car's dashboard lights up, this indicates that there are faults in the car that need to be repaired immediately. To find a breakdown, you should diagnose the ECU with an OBD 2 scanner and find out the error code. Only after a preliminary check using the Torque program can you look for a mechanical problem.

Lambda probe failure

Another malfunction of the fuel system that can cause the yellow icon on the instrument panel to light up is damage to the lambda probe or oxygen sensor.

It is installed in an engine with an injector to determine the level of oxygen in the fuel and control the turning on and off of the injectors to prepare a normal air-fuel mixture.

If the oxygen sensor or the wiring leading to it is broken, the electronic control unit will not be able to adjust the amount of oxygen and gasoline in the mixture.

At the same time, fuel consumption will increase, and the engine will be subject to increased loads. You can check the functionality of the probe yourself only if you have a multimeter. Otherwise, the road again lies in the service center.