When the ignition is turned on, the indicator lamp does not light up check engine, or it lights up, but goes out before the engine starts! In this article, I will tell you in detail about the causes of such a malfunction and give my recommendations on how to fix it.
According to the instructions, the “check engine” light should light up when the key is turned 180 degrees in the ignition lock, and then, after starting the engine, go out. But it happens that in various situations it stops burning even before the engine starts.
Why doesn't the indicator light up? C heck E ngine
So, the check must light up as soon as the NW of the car is turned on, and go out - as soon as the engine starts. This testifies to normal operation car. Otherwise, if the check is on while driving or does not react at all, diagnostics are needed in the service station.
First, let's find out what the purpose of the indicator is. It turns out that the check translated from English literally means “check the engine”. In other words, if the indicator lights up in the direction of travel vehicle, which means that the car's ECU sends a clear signal to the driver that there is some kind of malfunction in the operation of the internal combustion engine.
Unfortunately, the ECU is not capable of concretizing the problem. On the other hand, if you know which systems the check is responsible for, you can draw the appropriate conclusions.
In a previous article, I already managed to tell you about
It will not be so difficult to find the cause of the malfunction if the indicator does not light up after turning on the SZ. The driver got behind the wheel of the car, turned the key half a turn - the indicator should light up. If this does not happen, you need to try to test a few points yourself.
Does not burn Check Engine - the cause of a dead battery
The worst thing that could happen is a dead battery. The car stood for a long time without movement on the street or in the garage, respectively, the battery was discharged. It is not difficult to check such a development of events, it is enough to test whether the remaining lights on the instrument panel turn on, whether the headlights are on, etc. The battery for a modern car is a full-fledged power supply, and therefore no car electronics can function without it.
What can happen to the battery? Is it only to be discharged due to idle time? It turns out not. In addition, due to temperature differences, the contacts of the battery terminals can oxidize, and not transmit voltage. In addition, one of the terminals or both can simply move away, not sit very tightly, not providing proper contact. Another option is the wiring coming from the battery. It is also recommended to check it, since it is possible to break the wires in any place.
Check Engine does not light up when the key is turned - the ECU system is faulty
Other secondary causes
In addition, other reasons of a secondary nature are possible:
Failure in the system, because modern technologies, unfortunately, are not yet perfect and give out a lot of errors;
- Faulty fuses and relays responsible for the check engine light and the car's ignition system;
- Problems with the ignition lock, through which the system is turned on;
- Burnout of the bulb itself inside the instrument panel.
If you can’t find the reason why the check goes out when the ignition is turned on, you need to immediately go to the service. Remember that there may be a serious malfunction in the car, and your "iron friend" needs urgent help.
Video whyCheck enginedoes not light up when starting the engine
One of the most important elements is the electric fuel pump, which is located in fuel tank car. The fuel pump pumps fuel into the system from, creating a certain pressure.
Auto repair professionals identify the following common fuel system problems that are related to the fuel pump:
- the fuel pump pumps poorly and does not create the necessary pressure;
- the fuel pump does not pump when the ignition is turned on;
Given that the fuel pump is an electromechanical device, the most common fuel pump malfunctions are related to both mechanical and electrical parts. Next, we will consider what signs indicate a breakdown of the fuel pump and why the fuel pump stops pumping partially or completely.
Read in this article
Signs of a bad fuel pump
The main symptoms of the failure of the fuel pump, as well as failures in its operation, are:
- the car starts with difficulty, the engine is unstable, there are dips, jerks when you press the gas pedal, etc .;
- the pump does not pump after the ignition is turned on, and the fuel pump does not pump, the engine does not start;
There have also been cases when the fuel pump stops pumping right on the move. The engine in such a situation begins to malfunction and stalls immediately after the remaining gasoline in the fuel line is used up. The problem can occur both regularly and periodically.
The fuel pump does not pump: causes and diagnosis
Let's start with the fact that if the gas tank is full, charged, dry and there is a spark on them, the starter turns the engine normally, but the engine does not seize, then you should pay attention to the fuel pump. Frequent problem is that there is no power to the fuel pump after the ignition is turned on. In a similar way, the malfunction also manifests itself in motion, when the power to the fuel pump is lost and the engine suddenly stalls.
Not less than important point is also how much the fuel pump pumps. In other words, the pump may hum and buzz (power is supplied), but not create the desired pressure in the fuel line. Pressure in fuel system with a working fuel pump should be more than 3 bar (depending on the specific car model). The indicated pressure is accumulated in the fuel rail and has an indicator of 300 kPa and above.
To check, it is necessary to measure the pressure in the fuel rail with a pressure gauge, taking into account the indicators that are the norm for a particular car model. On the example of injection VAZs, the pressure when the ignition is turned on is 3 atmospheres, at idle the indicator is 2.5 atmospheres, when the gas is pressed 2.5-3 atmospheres. This method will help to accurately determine:
- malfunction of the fuel pressure regulator in the rail;
- breakdown of the fuel pump or a noticeable decrease in its performance due to wear;
- severe contamination of filters (fuel filter and / or fuel pump mesh);
In the second case, when you press the gas, the pressure does not increase, in the latter case, the pressure gauge needle rises, but very slowly or jerkily.
A decrease in the pressure indicator below the norm will lead to the fact that the engine may not start or start with difficulty, triple, twitch, work unstably and with failures. If this is the fault of the pump, and not fuel filter, then there is a high probability that the coarse mesh of the fuel pump is clogged. In this case, there is no need, since it will be enough to replace or even clean the mesh.
If there is a suspicion that there is no voltage to the fuel pump, there is a way to quickly check. It is enough to turn the ignition key and listen, since at the moment the key is turned, a slight hum of the fuel pump should be heard. If such a buzzing is not heard, then there is no power to the fuel pump, there are problems with the wiring, etc.
We add that this method of determining the operation of the pump by sound is not suitable for all cars. On some models (especially the premium class), the sound insulation is at a high level and the fuel pump turns on immediately after opening the driver's door, and not when the key is turned in the lock. In this case, it may seem that the fuel pump does not work when the ignition is turned on, while
the sound of the pump can simply not be heard.
Also in the general list possible causes, through which the fuel pump does not pump, are marked:
- failure of the fuel pump fuse;
- breakdown of the fuel pump relay;
- problems with the "mass" of the fuel pump;
- malfunction of the electric motor of the fuel pump;
- oxidation or a hall of contacts and terminals of the fuel pump;
- the fuel pump itself is faulty;
Wiring to fuel pump
On most cars, the wiring to the fuel pump consists of three wires: "plus", "minus", as well as a wire for indicating the amount of fuel in the gas tank. If the fuel pump is not pumping, then the cause may be a lack of power.
To check the power to the fuel pump, it is enough to take a 12-volt light bulb by supplying power to it from the external connector of the fuel pump. After turning the ignition, the control lamp should light up. If this does not happen, then the problem is in the external circuits. When the lamp comes on, it is necessary to check the internal contacts of the fuel pump.
To check the external wiring, alternately connect the positive and negative contacts that are removed from the fuel pump power connector to the pump ground. Contacts must also be connected to the fuel pump relay. If you place a negative contact on the ground, after which the ignition is turned on and the light comes on, then this means that this contact is faulty. In the event that the light bulb did not light up, then problems with the "plus" are obvious. If you place a contact on the relay and the light turns on, it is likely that the wire is damaged on the segment that connects the relay and the fuel pump itself.
Fuel pump electric motor
If checking the pressure in the fuel rail and external wiring to the fuel pump gives positive results, then the fuel pump motor should be checked. The specified electric motor is responsible for the circulation of gasoline inside the fuel pump.
During the check, it must be borne in mind that the terminals on the fuel pump themselves tend to oxidize, as a result of which power is not supplied and the pump does not pump. In this case, the motor is working, but the terminals need to be cleaned or soldered.
To believe the fuel pump motor, you need to fix the wires control lamp on the cleaned and serviceable terminal of the electric motor, after which the ignition should be turned on. If the light comes on, it indicates that the fuel pump motor is not working.
Fuel pump ground contact
Problems with the mass of the fuel pump may be indicated by a fuel level sensor that does not work correctly. The mass may be poorly fixed, in this case the fuel pump does not pump fuel. The ground wire is usually under dashboard and walks through the salon. It is necessary to find the indicated wire, check and clean all the contacts, then securely fix the mass on the fuel pump.
The fuel pump relay is often mounted next to the fuel pump ground, that is, under the dashboard. A normally operating relay after turning on the ignition in a couple of seconds allows the pump to create pressure in the system and immediately turns off.
At the moment the ignition key is turned, the driver hears a characteristic click (the relay is turned on), then a similar click will indicate that the fuel pump relay is turned off. If such clicks are not heard, this indicates a malfunction of the relay or its contacts. The best solution is to replace the fuel pump relay with a new or known-good device. We add that the cost of spare parts is quite affordable.
Fuel pump fuse
During diagnostics, be sure to check the fuel pump fuse. The specified 15 A fuse is usually located in the fuse box in engine compartment and is marked FUEL PUMP, which in translation means fuel pump.
The fuel pump fuse must be pulled out and inspected. The integrity of the contact will indicate that the device is normal. A damaged contact will indicate that the fuel pump fuse has blown. In this case, you need to install a new fuse, which has a very low cost(as in the situation with the fuel pump relay).
Other causes of fuel pump malfunctions
Quite often, unprofessional installation of additional electrical equipment or security anti-theft systems leads to the fact that the power to the fuel pump is lost due to reversed contacts or other connection errors.
Also, one should not exclude the possibility that a failure occurred in the car alarm or security complex, after which the fuel pump power is blocked. In other words, .
Finally, we add that the gasoline pump in the gas tank is immersed in gasoline, in which it is actively cooled. The habit of driving with an empty tank can quickly disable the fuel pump electric motor, as it burns.
Read also
What functions does the fuel pump relay perform, signs of breakdown. Where is the fuel pump relay installed, how to properly check the fuel pump relay.
Often, we notice malfunctions in the operation of the car directly while driving it. However, it also happens when you comfortably sit in the driver's seat, insert the key into the ignition with the usual movement and turn it 180 °, instead of the usual "roar" of the engine, you do not hear anything. It is clear that this situation does not promise anything good, but if you already had to face it, you will have to solve the problem immediately. After all, not everyone can afford to be without a car. In today's article, you can learn all about the most common ignition malfunctions, the features of diagnosing this car system, and troubleshooting all problems.
1. What should I do if the car ignition does not turn on?
The lack of response of the ignition switch to turning the key is probably the worst thing a car owner should expect. On the one hand, a breakdown can be completely trifling, but on the other, try to find this breakdown first. Indeed, under the hood of a car there are so many systems and individual parts with which it is connected that you can spend several days in a row looking for the cause of the malfunction of the latter. Almost every node can cause the car to not start.
So, let's figure out what to do if the ignition does not turn on. Of course, it is necessary to carry out an initial diagnosis of the car and try to determine what is wrong. In particular, some ignition malfunctions can be identified even by a number of external signs. The fact is that they can coincide with malfunctions in the fuel supply systems to the engine combustion chamber. In this regard, the primary diagnosis must necessarily be comprehensive.
TO outward signs Ignition faults include:
- difficulty in attempting to start the engine or inability to do so;
Instability in the engine idling;
A noticeable decrease in the power of an automobile motor;
Increased fuel consumption during normal driving.
Undoubtedly, the voiced signs can appear if the ignition, although with difficulty, works. However, many car owners do not attach much importance to them and begin to grab their heads even when the ignition does not turn on at all. In such a situation, it will be very difficult to correct the situation, and the most right advice will sound like this: immediately contact the specialists. But if you don’t have such an opportunity, and you are eager to try to get out of the situation yourself, first of all you should familiarize yourself with the most common ignition malfunctions.
2. Most Common Ignition Faults: Should You Panic?
In order to determine the breakdown and, of course, fix it, you need to know about the existence of different ignition systems that can be found on cars today:
- contact system- high voltage in the system and its transfer to the cylinders is carried out using contacts;
- contactless- the contact interrupter is replaced here by a contactless sensor;
- electronic- high voltage in the system and its transfer to the cylinders is carried out using a special electronic device.
But no matter what system is installed on your car, the malfunctions can be identical. The most common for all of the above systems are the following:
- malfunctions associated with incorrect operation or burnout of spark plugs;
Ignition coil malfunctions;
Rupture of connections in the electrical circuits of the car - chafing of wires, loose connections, oxidized contacts).
Insofar as electronic system is the most common for modern cars, then it is worth noting another, very common cause of failure for her. Of course, a malfunction can lead to such a situation. electronic block driving, which has a direct impact on the operation of the ignition. Most often, the reason lies in the presence of defects in the input sensors.
With a non-contact system, the situation is even worse, since even the cover of the sensor-distributor can interfere with its operation. Also, if the ignition does not turn on contact system, then the reason may be hidden in a malfunction of the transistor switch or ignition timing controllers.
But in general, there can be a lot of reasons, although with the departure of the contact ignition system, most of them have ceased to be relevant for modern car owners:
- incorrect operation. For example, the tank was filled low-quality gasoline, or the frequency of maintenance of the fuel pump was very large;
The system included low-quality structural elements, which include candles, high- and low-voltage wires, and the ignition coil itself;
Influence on the car and its systems of a number of external factors. We are talking not only about the impact of atmospheric phenomena, but also about possible mechanical damage.
Specialists, on the other hand, divide all ignition malfunctions into three general categories: problems associated with electronics, with an ignition coil, and low-quality fuel. Of course, such a classification is very primitive, but it is necessary to focus on it if the ignition does not turn on.
Ignition faults associated with incorrect connection and operation of automotive electronics Since this is the most common cause of ignition failure, then First of all, you need to pay attention to the fuses. Of course, not all ignition systems have fuses, but if they do, make sure none of them are blown. If the matter is not in them, then the reason may be hiding in:
1. Car battery corrosion. Due to long-term operation and the influence of external factors, the power supply connectors become dirty and may even become rusty. Because of this, the connection between the battery and the rest of the "organism" of the car is broken. To understand if this is really the case, you should either clean the rust off the terminals or replace the battery. If the car still does not start, the cause will have to be looked for further.
2. The battery that just sat down.
You can check the current strength of the power supply using a conventional tester. However, this can also be understood by external signs: if, when the starter is turned on, there is still a slight push, it means that the battery is really discharged.
3. Broken ignition switch. Try turning the key to the first position and see if the red lights on the instrument panel light up. If not, the problem is in the ignition switch. Also, if when you try to start the car, the lights of the signal lights do not go out and do not even dim, the reason may be hidden in a malfunction of the ignition switch.
4. Faulty starter connections. This element can also corrode over time. If there is voltage in the system, but the starter does not respond to key turns, most likely it will need to be replaced.
Ignition Coil Malfunctions
To determine the performance of the ignition coil, you must use special device called a multimeter, which is designed to measure the resistance force. If after testing you find that the coil does not work, it must be replaced immediately.
Together with the coil, it is important to check the cover of the ignition distributor. The fact is that with temperature changes and due to high humidity, water can accumulate under its cover. If, after removing it from the distributor, you find condensation, wipe the cover with a dry cloth. Also pay attention to whether there are any cracks on it. Once the cover is back on, try starting the car again.
If the ignition does not turn on, then the reason may also be hidden in the wire of its coil. It can either break or burn out due to a short circuit. If there are obvious traces on it, the coil must be replaced.
Ignition faults caused by the use of bad fuel
Bad fuel is also a very common reason why the driver fails to start the car. If we are talking about injection engines, then we can name a number of subsystems that can cause a similar situation. And the main difficulty lies in the fact that such problems can be diagnosed only through serious computer diagnostics. However, we will still tell you about some things that can be implemented even in the garage:
1. Check the electrical systems that are directly responsible for fuel injection. You need to find the connector on the top of the injector itself, as well as inspect the connections on the intake and on the cylinder heads. Ideally, check all electrical connections.
2. Relay and fuel pump. To obtain a 100% reliable diagnosis, you need special equipment. If not, then the only thing you can check is again the electrical connections of these elements.
Replacing the ignition coil, as well as its lock.
We hope that you will be able not only to determine the cause of the ignition malfunction, but also to successfully eliminate it. Moreover, you already have the necessary knowledge for this.