What is the reason why the engine fault light turns on and off?

Possible causes of car engine failure lights on:

1, the vehicle fault light is generally caused by the fuel emission system, you start and extinguish the vehicle when the fault light is on, and after starting the vehicle three times, you observe whether the fault light is still lit, or it is still lit, you need to go to the store in time to check the fault code, to see whether it is an engine problem or a sensor failure, or it may be an occasional failure can not be checked in time.

2. When the computer receives the parameters of the oxygen sensor, the exhaust emissions seriously exceed the national legal standards, and the internal program of the computer cannot be corrected to the standard range, at this time, the engine control computer will issue a warning light (yellow pollution lamp on) through the instrument to remind the owner to the maintenance station to check the cause of the engine pollution emission lamp.

The automobile engine is the machine that provides power for the car, and it is the heart of the car, which affects the power, economy and environmental protection of the car. According to different power**, automobile engines can be divided into diesel engines, gasoline engines, electric vehicle motors, and hybrids.

Common gasoline engines and diesel engines belong to reciprocating piston internal combustion engines, which convert the chemical energy of fuel into mechanical energy of piston movement and output power to the outside world. The gasoline engine has high speed, small quality, low noise, easy starting, and low manufacturing cost; The diesel engine has a large compression ratio, high thermal efficiency, and better economic performance and emission performance than the gasoline engine.

In addition to the use of gasoline and diesel, vehicles that use other new energy sources are called new energy vehicles, including pure electric vehicles, hybrid electric vehicles, fuel cell vehicles, gas vehicles, bioethanol biodiesel vehicles, and hydrogen-powered vehicles. Most of the new energy vehicles on sale in the Chinese market are hybrid vehicles, but at present, pure electric vehicles have been taken as the main direction.

Hello, the engine fault light may be a temporary failure, the specific manifestation is that the car is driving without obvious symptoms, and the engine fault light is on for a period of time and off for a period of time. Temporary failures may seem insignificant, but they can also be "hidden killers". Therefore, the owner should not ignore it and should find time to check the vehicle.

If the fault light is always on and accompanied by other abnormal conditions, including the engine cannot be started, easy to stall, engine shaking, power dropping and other problems, you should contact the 4S shop as soon as possible.

or a repair shop for overhaul.

Sensors, maintenance issues, oil problems, intake problems, poor combustion of the mixture, etc., can all cause the engine fault light to illuminate. The engine is the core component of a car, and the corresponding fault light is on, which either means that there is really a fault; Either the engine is experiencing a false signal false alarm failure. Don't underestimate the engine failure light, it may not have a noticeable impact in a short period of time, but if left unattended for a long time, the vehicle may eventually have a serious failure.

1. Sensor.

Damaged sensors, poor contact, or signal interruptions cause the car's ECU to receive incorrect engine data and finally turn on the engine fault light with a misjudgment. There are many automotive sensors, the core of which is water temperature and crankshaft.

Position, air flow, inlet air temperature, oxygen sensor.

Wait. Solving the engine failure caused by the sensor is very simple, and you only need to replace or adjust the sensor that has the problem.

Oxygen sensor: There are two oxygen sensors, respectively in the three-way catalytic converter.

Before and after, the role of oxygen sensors in different positions is different. The front oxygen sensor needs to detect the air-fuel ratio of the engine under different operating conditions, and the data will help the car computer to adjust the fuel injection amount and calculate the ignition time. Post-oxygen is used to detect the working condition of the three-way catalytic converter.

An over-concentrated or over-dilute mixture is a direct effect of an oxygen sensor problem and can also illuminate an engine failure light.

Air Flow Sensor:

Also known as an air flow meter, its role is to calculate the amount of air and convert it into an electrical signal, which is determined by the engine computer based on the optimal air-fuel ratio. Similarly, the effect of an abnormal air flow sensor is that the mixture is too thick or too thin, causing the engine failure light to illuminate.

2. Oil. In fact, there are strict requirements for the oil of the car, and we only need to fill the qualified oil to meet the normal operation of the engine. Although the unqualified oil can support the operation of the engine, the engine is uncomfortable to run, so the wear will be accelerated, and the engine fault light will also be lit.

3. Mixed gas combustion.

Spark plug. Problems such as malfunctions, ignition coil failures, fuel pump failures, and clogged oil circuits can all lead to poor combustion of the mixture. The consequence of poor combustion of the mixture on the engine is carbon deposit.

or knocking, which causes the engine failure light to illuminate. Measures such as replacing spark plugs, cleaning oil circuits, and cleaning up carbon deposits have a certain chance of eliminating faulty lights.

The engine vehicle fault light is generally caused by the fuel emission system, you start and extinguish the vehicle when the fault light is on, and after starting the vehicle three times, you observe whether the fault light is still lit, or it is still lit, you need to go to the store in time to check the fault code, to see if it is the problem of the engine or the sensor failure, or it may be an occasional failure, you can not go to the store in time to check.

1. The fault light is on because the engine control computer detects that there is a fault in the control system, and the computer will also record the fault code and some key data when the fault occurs. 2. The main reason for the engine failure light is that the throttle or the carbon deposit inside the engine is too much, resulting in the imbalance of the mixture proportion, and it is easy to turn on the engine fault light 3.

A certain part or sensor of the car is on the verge of damage, and there will also be fault lights that sometimes turn on and sometimes go off: the parts or sensors are good and bad, and the fault lights will be turned on when they are damaged, and the fault lights will go out again after a good period of time, and the communication between the sensor and the computer will be interrupted once or for a period of time due to unexpected circumstances, and the computer will also think that it is a fault and light up the fault lights, but then the communication will be restored, and the fault lights will automatically go out after a few fires.

The engine fault light turns off as soon as it turns on, possibly due to some temporary fault.

Abnormal engine exhaust emissions, engine carbon deposits, etc., may cause this phenomenon.

The sensor falsely reported a fault**. When using the vehicle, the trip computer finds that there is no real fault. After multiple ignitions and self-tests, the fault light will go out automatically.

If the communication between the sensor and the computer is interrupted once or for a period of time due to an accident, the computer will also treat it as a fault and turn on the fault light. However, after communication is restored, the fault lamp will automatically go off after multiple ignitions.

What is the reason why the engine fault indicator light is on for a while and not for a while. When a part or sensor is on the verge of damage, it will be good and bad, and when it is, the fault indicator will illuminate. After some time, the fault indicator will turn off.

Other unexpected situations, such as problems with adding gasoline, missing cylinders due to poor combustion, normal combustion after changing the oil, etc.

When the engine fault indicator is on, there are three scenarios. The first is that the car won't start. This can be caused by a malfunction of the fuel pump or ignition part.

Call for help directly. The second is that the fault light is on, but there is no abnormality in driving. This could just be a sensor failure.

In this case, you can continue driving for the time being, but it is best to drive slowly at low and medium speeds, and make repairs when you reach your destination. Third, if the engine fault light is on, the vehicle can drive, but if there are symptoms such as severe shaking and weak acceleration, it should stop immediately and call for rescue.

There are several possibilities for this scenario. First, the sensor falsely alarms the fault**. When using the vehicle, the computer found that there was no real fault.

After multiple ignitions and self-tests, the fault light will be turned off. Secondly, if the communication between the sensor and the computer is interrupted for one time or a period of time, the computer will also think that it is a fault due to an accident and turn on the fault light. But then communication is restored, and the fault indicator will automatically go off after a few fires.

Thirdly, the part or sensor is on the verge of damage, sometimes good and sometimes bad, and the fault indicator will illuminate when damaged. After some time, the fault indicator will turn off. Fourthly, there are other accidents, such as the problem of adding gasoline, poor combustion, resulting in a shortage of cylinders, normal combustion after an oil change, etc.

It may be that there is carbon deposit in the cylinder of the car, the engine is faulty, the temperature of the car is too low, and the damage of the car battery will cause the engine light to fail.

It may be because the engine temperature is too low, or it may be that the quality of the gasoline is too poor, and you can go to the auto repair shop to check it.

In this case, it is likely to be caused by cylinder carbon deposits, and the problem of carbon deposits must be dealt with at this time.

This is a self-check when starting the vehicle.

The engine fault light is to detect whether the exhaust emissions are normal through the sensor, when the standard is exceeded, then there will be an alarm of the engine warning light, in most cases, after the light is on, it will disappear after a while, then it means that he has no major problems, don't worry too much. It is likely that after the car is started, some problems caused by poor atomization in the cylinders of the fuel engine cause the engine to alarm. Then you don't have to worry about it, when the temperature comes up, the warning light will naturally go out.

Let's talk about buying a car, using a car, maintaining a car, and repairing a car.

If the engine fault light is on, there is no abnormal noise in the cabin, there is no other abnormal prompt in the instrument, the vehicle power is not affected, and the gearbox upshift is not affected, you can continue to drive and stop the 4S shop for further investigation, because the intake and exhaust may cause the engine failure light to be on, and the specific problem is analyzed in detail.

This is commonly referred to as the yellow engine fault lamp, also known as the EFI system fault lamp. As long as there are no special abnormalities in the engine power and sound, it can still continue to drive. Because there is a substitute bug program in the ECU.

Once one of the many sensors has a sensing failure, in order to ensure the normal operation of the engine, the ECU will replace the parameters of the faulty sensor according to the pre-set backup parameters to avoid vehicle breakdown. For example, if the water temperature sensor is broken, the ECU will use a backup value of 80 degrees as the control parameter for fuel injection and ignition. So it can be opened, but it must also be repaired in time.

There are two situations when the engine fault light is on: the yellow symbol light indicates that the engine is faulty, but the fault does not affect the normal operation of the engine, but it must be maintained. The red symbol light indicates that the engine has a serious fault, and it needs to be repaired immediately under normal circumstances, if it is in special road conditions, it can be used in an emergency, but it is necessary to pay attention to the working status of the engine at all times.

The temperature is low at the start, and the gasoline atomization is not enough It is difficult to start when the cold car starts in the morning or the starting condition is unstable after starting. When the engine starts cold, the cylinder wall and other parts of the engine are cold metal parts, and when the engine is running, the fuel injection of the fuel injector into the cylinder is atomized. The atomized mixture encounters the cold cylinder wall and is condensed on the cylinder wall.

The reason why the engine fault light turns on and goes out is: too much carbon deposition inside the throttle or engine, resulting in the misproportion of the mixture, and the engine fault light is on, and the fault light is no longer in several working cycles, and the fault light is extinguished. The solution to the engine failure light that turns on and off:

1. Replace the oxygen sensor; 2. Replace the three-way catalytic converter; 3. Tighten or replace the fuel tank cap; 4. Replace the thermostat; 5. Replace the ignition coil; 6. Replace the air flow sensor; 7. Maintain on schedule, and maintain it on schedule according to the time cycle of the vehicle maintenance card.

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Let's talk about buying a car, using a car, maintaining a car, and repairing a car.

First, when the car is used in winter, because the temperature is low when the vehicle is started, the fuel inside the engine is not atomized, which makes the gasoline combustion effect poor and the exhaust gas is abnormal, so that the engine warning light will automatically alarm. However, when the engine temperature rises, the car will be able to drive normally, and the engine warning light will automatically go off.

Second, for some "classic cars" that have been used for a long time, the engine failure light may also be lit when it is just started. For some old models, the carbon deposit inside the engine has been relatively large, and when the car has just started, the fuel is easy to be adsorbed by carbon deposits, so the exhaust gas is not normal. However, after the car has been driving normally for a while, the engine is working normally, and the fault light will go out.

Third: In the process of rapid acceleration of the car, sometimes the fault light may be lit because of the owner's foot on the accelerator. When the owner steps on the accelerator, a large amount of air will enter the engine under normal circumstances, but if the air filter is blocked, the air intake will not be smooth, and the engine fault light may also turn on.

Fourth: If you add poor quality gasoline to the car, it may also cause the engine fault light to illuminate. When using poor quality gasoline, sometimes there are too many impurities in the gasoline, which makes the internal combustion of the engine incomplete, so the fault light is on; However, after all, there is a gasoline filter element that can play a filtering role, and inferior gasoline generally does not have any impact on the engine, but the owner should still pay more attention to it, and replace the qualified gasoline immediately after the inferior gasoline is used up.