Many of us have faced such a problem as the inclusion of an indication of the engine icon (Check engine ...), the appearance of which scares the drivers of cars. Here are the 5 most common reasons why dashboard the check of the engine lights up.
The engine gauge icon usually appears without warning. The reason for the appearance of the Check engine cannot be immediately understood. Even if there is an auto diagnostics in the car (for example, in such cars as,), which scans all systems of the car for errors and, if any, displays a decryption on the information panel, the reasons for the appearance of the engine check will not be decrypted.
For most drivers, the appearance of this warning symbol on the instrument panel means that they urgently need to go to a car workshop to diagnose and eliminate the reason for which the engine check warning sign appeared. But in fact, in most cases, when the "Check" indication appears, it is possible, and in some cases, perhaps, to eliminate the cause on your own without a trip to a car service, which will save your money.
1. Replace the oxygen sensor (lambda probe)
The oxygen sensor in your car is part of the exhaust system exhaust gases, which controls how much oxygen is not burned out in the engine's combustion chamber. This sensor helps to monitor the fuel consumption of the vehicle. A malfunctioning oxygen sensor (lambda probe) means that the car computer receives incorrect data, which can significantly increase fuel consumption and reduce engine power. Most cars have 2 to 4 oxygen sensors. If you have a home car error scanner, then by connecting it to the car, you can easily find out which sensor needs to be replaced.
For what reason the oxygen sensor in the car becomes unusable: Over time, the sensor becomes covered with a layer of waste and engine oil(oily soot), which reduces the accuracy of reading the sensor readings to regulate the gasoline mixture and distribute the optimal one. A malfunction of the oxygen sensor in the car leads not only to, but also to an increased content of harmful substances CO2 in the exhaust.
What needs to be done: If you do not change the defective car sensor oxygen, this can lead to failure of the catalyst of your car (may burst), which will result in costly repairs. The cost of new catalysts is very high due to the content of precious alloys in them. On some cars, there are several catalysts, the cost of which can go up to 90,000 rubles. So do not delay replacing the sensor. Although the replacement of the sensor and its cost is not very small, it is not commensurate with the cost of the exhaust gas neutralizer system. You can also save on replacement costs by doing it yourself. Many car manuals have detailed instructions how you can replace the oxygen sensor yourself. If you know where the oxygen sensor is, then it will not be difficult for you to disconnect the faulty "lambda probe" and replace it with a new one. Remember to pull with the replacement of this important element you can't pull!
2. Check the fuel filler cap
Many drivers in most cases, when the "check engine" indication appears, will think about serious problems in the car's engine, but will not even think to check the tightness fuel system, which can be broken due to a defect or insufficiently tightened neck cap fuel tank... This is a very common reason for the "Check" engine icon to appear.
The reason for the error: Leakage of the fuel system due to the passage of air, the fuel filler cap, will increase the fuel consumption of the car, for which the car diagnostic system will give an engine error by turning on the "Check engine" indication on the dashboard of the car.
What needs to be done: If, when the "Check" indication appears, your car has not lost power, and there are no sound signs of engine damage (knocking in the engine, hum, creaking, etc.), then first of all check the tightness of the gas tank. Your gas cap may be cracked or not tight enough. If the cover was not tight enough, then after tightening it all the way, continue driving the car for a while to see if the engine error disappears. To prevent the appearance of an engine check for this reason, regularly check the fuel filler cap. Remember to periodically replace the cover with a new one!
3. Car exhaust gas catalyst
The car catalyst helps the car to make the exhaust gas from the engine more environmentally friendly. It converts carbon monoxide and other harmful substances into harmless compounds. If your exhaust gas catalyst has become unusable, you will notice this not only when the engine badge (check) appears, but also long before that, when the car's power drops by 2 times. For example, when you press the gas pedal, the car, as before, will not have good acceleration dynamics.
Because of what the automobile catalyst can fail: if you regularly service your car, in accordance with the maintenance regulations car company, then the catalyst should not fail. The main reason for the failure of the catalyst is the untimely replacement of a faulty oxygen sensor, as well as irregular replacement of spark plugs at the end of the expiration date. When the oxygen sensor or spark plugs are faulty, the conversion of carbon monoxide in the catalyst into harmless chemical elements stops, which leads to overheating of the catalyst, which can be damaged as a result.
What needs to be done: If your catalyst has become unusable, then you cannot drive the car, since the engine will not work correctly, warning about this by an indication on the dashboard with an engine icon (check). Also, your fuel consumption will be greatly increased, and there will be no engine thrust. Although replacing a catalyst is a very expensive repair, there is nowhere to go from repairs. Although there is an alternative to replacing the catalyst with a flame arrester, this is not a 100 percent option. Unfortunately, if you are not an experienced auto mechanic, then you cannot replace a faulty exhaust gas catalyst yourself. In any case, you will have to go to a car repair shop. Remember that timely replacement of oxygen sensors and spark plugs protects your catalyst from damage!
4. Replace the MAF sensor
The mass air flow sensor regulates how much air needs to be added to the gasoline mixture to optimally ignite the fuel. The sensor continuously informs the vehicle computer of the amount of oxygen supplied. A defective MAF sensor will increase fuel consumption, increase CO2 levels in the exhaust gas, and reduce engine power and ride smoothness. Also, with a faulty sensor, poor acceleration dynamics is observed. In cold weather, a car with a faulty sensor will not start well.
What are the reasons for the failure of the mass air flow sensor: Most sensor failures occur due to improper installation of the air filter during its scheduled replacement. Also, if you do not regularly change air filter as required by the regulations Maintenance vehicle recommended by the manufacturer, the MAF sensor may be damaged.
What needs to be done: In theory, you can drive for a long time with a broken MAF sensor (several weeks or months). But you will notice that the longer you drive, the more fuel consumption increases. Replacing a sensor in a car service is not that expensive, since the work itself does not take much time and is quite simple. The main costs are associated with the cost of the sensor, which for some car models can be 11,000-14,000 rubles if it is an original sensor or up to 6,000 rubles if it is an analog substitute. Self replacement the sensor is very simple. But due to the low cost of replacing the sensor, you can entrust this work to a master in a car service. Remember that you need to regularly change the air filter, observing the vehicle maintenance regulations!
5. Replacing spark plugs and high voltage wires
Spark plugs in a car are the main parts for igniting the fuel mixture. With faulty spark plugs, the spark is incorrectly supplied to ignite the gasoline mixture. Defective spark plugs often have a lack of spark or an incorrect spark interval, which affects engine malfunction. If the spark plugs do not work properly during acceleration, especially from a standstill, you may feel small jolts.
What are the reasons for the failure of spark plugs: Most spark plugs in vehicles prior to 1996 need to be replaced every 25,000-30,000 kilometers... In newer vehicles, spark plugs last over 150,000 km. However, these spark plug replacement times can be reduced due to various factors related to fuel quality and driving style.
What needs to be done: If your spark plugs have not changed for a long time, or you feel dips associated with ignition in the engine, then you must immediately replace them with new ones without delay. Do not try to save on untimely replacement spark plugs, since the cost of the plugs is not very expensive, as is the work of replacing them. Replacing old spark plugs will improve engine performance and reduce vehicle fuel consumption. It is quite easy to change spark plugs on your own. Mostly they are easily accessible under the hood of the car. You need an ordinary candle wrench to remove the spark plugs from the engine. It is also advisable to monitor the status high-voltage wires, as over time they can become unusable and allow electricity to pass, which is transmitted to the spark plugs, which will reduce the strength of the spark. Remember that regular replacement of spark plugs, in accordance with your car's maintenance schedule, keeps your exhaust catalyst from damage, and also improves engine performance!
If the Check engine indicator light on the dashboard of your car lights up (or simply the "check" is on), you should at least be alert. The reasons for this can be very diverse - from a loose gas cap to serious engine problems.
What does the Check engine indicator mean
The name of the Check engine indicator literally translates as "Check the engine". However, the engine, when the light comes on or flashes, may have nothing to do with it. A lit indicator may indicate problems in the fuel supply system, failure of individual ignition elements, etc.
Sometimes this can be a very minor problem - for example, a loose fuel cap or a catalyst malfunction. Nevertheless, it is impossible to ignore the indicator signals in any case, as this can result in serious problems.
Sometimes the reason for the indicator to light up may be poor fuel quality. So do not be surprised if, after refueling at an unfamiliar gas station, you see the Check engine light blinking.
Usually the indicator is located on the dashboard of the car under the engine speed indicator. It is indicated by a schematic engine or a rectangle labeled Check engine or simply Check. In some cases, a lightning symbol is depicted instead of an inscription.
Is it possible to continue driving when the light is on
The brake pads are worn out, the time has come for the next maintenance, the speed is incorrectly switched, the fuel is of poor quality, the voltage has dropped on-board network- all this can be a reason for the Check indicator to light up. First of all, you should check the motor. If the alarm is triggered by engine malfunctions, it is dangerous to continue driving.
The problem is aggravated by the fact that it is impossible to independently determine the malfunction of a modern ICE by smell or color. You should contact a professional who, using a scanner, will identify a malfunction, if, of course, there is one.
A lit Check light may indicate various breakdowns - it is better not to ignore it
Therefore, if after restarting the car the light has not gone out, you can only drive to the nearest car service. They will conduct a comprehensive diagnosis of the engine and its systems.
Operation of a car with a lit Check engine icon leads to increased consumption fuel, precarious work motor, decrease traction characteristics car. Moreover, in this case, the car owner may lose the car repair warranty.
Why the light bulb came on and how to fix it
The main situations in which the indicator lights up, and the recommended options for the motorist's actions:
- If the Check engine lights up and immediately goes out when the car is started, there is no damage to the engine. The reason for the fire is most likely harmless - the loss of the fuel tank cap or its not twisting. It is enough to wrap it tightly and check if the warning has disappeared.
- If the indicator lights up while driving, you should stop and check the wires. You may find a cable free hanging under the hood or an open battery terminal. This applies to everything attachments- wires, hoses, etc.
- If the light flashes while driving, stop and check the sounds made by the engine, pay attention to the oil level, inspect the side parts of the engine. If no visually obvious violations are found, it is recommended to drive to the nearest car service and carry out diagnostics.
- If the engine is running normally and the Check light is flashing continuously, it is most likely an ignition failure. You should check the candles and the coil, pay attention to the quality of the fuel. To do this, it is better to contact the nearest autodiagnostic center.
- If the indicator is constantly on, you must stop, unscrew the candles and check the gap. Gaps that exceed 1.3 may cause the light bulb to come on.
- In addition, when the "check" is lit, the ignition is usually checked. In any car service there are special testers that allow you to determine the deterioration of the insulation of the wiring.
- The reason for the light bulb to light up may also be a faulty fuel pump... You should stop and listen to the sounds from the gas pump. Smooth humming without clicks and pauses is considered normal. If appear extraneous sounds, the pump should be dismantled, rinsed from the inside and the filter should be cleaned.
- A serious engine malfunction may be indicated by the coolant temperature. If it is higher than 85–90 degrees, and the Check engine lights up when driving, the engine is definitely faulty. In this case, it is advisable to call a tow truck or drive at low speed to the nearest car service.
We have already noted that Check lights up yellow or orange every time the engine is started. It is normal for the blinking to last no more than 3-4 seconds and stop along with the blinking of the other dashboard lights. Otherwise, follow the recommended steps above.
Video: Check sensor lights up
https://www.youtube.com/embed/uqdKfKX4MlE
Table: Causes of the Check Engine Light to Come On and Suggested Actions
| When and in what cases the "check" is lit | Possible reasons | Suggested action |
| When driving, when accelerating | Rapid acceleration, faulty air filter | Change filter, accelerate more smoothly |
| When the indicator blinks, the engine trips | Fuel in one of the cylinders does not burn completely, gasoline or burns out in exhaust pipe, or immediately enters the catalyst | Replace spark plugs, check coil and armored wires, check timing marks |
| After refueling | Poor fuel quality | Change gas station |
| When the ignition is turned on | Normal vehicle response | Shouldn't do anything |
| After washing the car, engine, after rain | Water has spilled on the Check engine wiring | Treat WD40, dry, clean contacts |
| On a cold engine | Knock sensor defective | Replace |
| On a hot engine | Defective camshaft sensor | Replace |
| At high revs | Missing ignition coils or faulty crankshaft sensor | Replace coil or sensor |
| Idle | Sensor malfunction throttle | Replace |
| After replacing candles | "Lean" combustible mixture | Change the octane number of gasoline to a higher one |
| After replacing the air filter | More air began to flow, the composition of the exhaust changed, the lambda probe reacted | Stop the engine, start again |
| After replacing the timing belt | A terminal has jumped off a sensor, most likely D. of the air hose | Check terminals |
| After installing LPG equipment | Fuel injector emulation made incorrectly | Tune |
| After setting the alarm | Only one power line is connected to the turbo timer, the temperature sensor, brake pedals and mass air flow sensor hang on the second | Reset Check engine, connect both lines |
| After replacing the fuel filter | Low pressure filter installed | Replace filter |
| With a simultaneous increase in fuel consumption | Driving too long, heating up the oxygen tank, or poor-quality fuel | Refuel with quality fuel, let the car rest |
| With long climbs | Timing belt wear, sensor malfunction | Check and replace |
| After replacing the ignition module | Module connection problems | Remove and replace the positive terminal from the battery |
| At subzero temperatures | Throttle position sensor defective or disconnected | Replace the device or install the chip in place |
| When you press the accelerator pedal | Clogged air filter | Clean or replace filter |
Resetting or zeroing the Check indicator
In most cases, as the table shows, Check lights up when a sensor fails or changes in vehicle operating conditions. However, even after diagnosing and eliminating the malfunction, the light sometimes stays on.
The point is that the "trace" of the error remains in the computer's memory. In this case, you should "reset" or "zero" the indicator readings. This can be easily done on your own by performing a number of simple operations:
The sensor has been reset and the Check light is no longer on. If this does not happen, contact the service center.
When the Check engine light on the dashboard comes on, it almost always requires the vehicle to stop immediately. Practical use of the recommendations given in the article will help you avoid complex and expensive engine repairs. Good luck on the road!
Good evening everyone. The problem with the check was solved without diagnostics thanks to your advice, for which I am very grateful. the fuse in the air heater circuit was burning, due to the short circuit of the air heater on the intake manifold. As airedogs wrote.
And it is possible in more detail and in the pictures, it is desirable (where is this heater and where is the fuse itself). A very similar situation. It manifests itself when the gas pedal is pressed strongly (almost to the kickdown) and immediately disappears when released, while no loss of power and other problems were found
It’s fictional for diagnostics, it will cost about 50 euros and it’s not a fact that a diagnosis will be made, but to ride on different services and pay 50 euros everywhere while there is no desire. To begin with, I would like to see all the possible options.
And by the way, how much is the normal consumption? I have 10.5-11 liters on the highway on the machine, and 12-13 liters in the city. At the same time, we do not have a lot of traffic jams, usually the speed of movement is 60-70 km per hour .... but the dog does not switch to the 4th for saving in any way))) only switches about 80. By the way, no one knows if the machine can be adjusted to shift gears? For me on a Mercedes w140 on the same ancient machine, the master machine gunner during the repair adjusted the switching so that at 55 km / h I switched to the 3rd, and at 75 to the 4th. Since I drive according to the rules and on the highway no more than 100 km / h, it turned out more economical
Hello. Unfortunately, I can't upload photos.
