It stalled on the go and the automatic transmission does not start: causes and measures. automatic transmission stalls

28.09.2019

Hello! Help, please, the car with automatic transmission has stalled and will no longer start. What to do? (Mumin Kurbonov)

Mumin, good afternoon. Automatic transmission - the unit is quite complex and whimsical in terms of operation and maintenance. Therefore, one wrong action can cause the engine to stall and not start. We will try to help you with your issue.

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Why does a car with automatic transmission stall?

There can be several reasons for this behavior of the car. Let's say right away that only high-quality diagnostics will help to accurately identify a breakdown, and the information below is only a theory, since we have not seen your car and do not know under what circumstances it stalls.

So, the most common reasons are:

Very poor fuel quality. On low-quality gasoline, diesel or gas, the car may not drive at all. In practice, this problem usually manifests itself in those motorists who put gas installations on their cars and refuel with low-quality gas. It is necessary to get rid of low-quality fuel and fill in new. If your car is equipped with LPG, then you also need to check the gas filter. The performance of the filter fuel elements should be checked on both gasoline and diesel cars.
Damage to the mass air flow regulator. We recommend that you check the device’s performance, as well as its connection diagram, perhaps there was a break or short circuit in the wiring.
Fault . With such a problem, the car may stall right on the go. As in the previous case, it is necessary to check the operation of the regulator, as well as its wiring.
If the vehicle stalled during braking, then the breakdown may well be related to the vacuum brake booster. We recommend diagnosing the mechanism only if you know how to do everything right.
Clogged throttle valve. As practice shows, it is the throttle in most cases that causes the car to fail to start.
Naturally, you should also check the fuel level in the tank.

In any case, if you do not know how to diagnose the transmission, then you need to seek help from specialists. With the help of a computer check, a professional will diagnose the unit and identify all possible malfunctions in the form of codes that need to be deciphered. If necessary, it will be possible to check the operation of the engine itself.

Hello! Help, please, the car with automatic transmission has stalled and will no longer start. What to do? (Mumin Kurbonov)

[ To uncover]

Why does a car with automatic transmission stall?

So, the most common reasons are:

Very poor fuel quality. On low-quality gasoline, diesel or gas, the car may not drive at all. In practice, this problem usually manifests itself in those motorists who put gas installations on their cars and refuel with low-quality gas. It is necessary to get rid of low-quality fuel and fill in new. If your car is equipped with LPG, then you also need to check the gas filter. The performance of the filter fuel elements should be checked on both gasoline and diesel cars.
Damage to the mass air flow regulator. We recommend that you check the device’s performance, as well as its connection diagram, perhaps there was a break or short circuit in the wiring.
Malfunction of the crankshaft position sensor. With such a problem, the car may stall right on the go. As in the previous case, it is necessary to check the operation of the regulator, as well as its wiring.
If the vehicle stalled during braking, then the breakdown may well be related to the vacuum brake booster. We recommend diagnosing the mechanism only if you know how to do everything right.
Clogged throttle valve. As practice shows, it is the throttle in most cases that causes the car to fail to start.
Naturally, you should also check the fuel level in the tank.

Video "Peculiarities of operation of automatic transmission"

Everything about the operation of a car with automatic transmission is on the video (author - Vladimir Grechaninov).

autozam.com

Stalls when D or R is turned on

There were several cases in practice when cars stalled from setting the automatic transmission selector to the drive or reverse position. At the same time, everything worked perfectly in neutral and parking. Also, the malfunction was of a periodic nature - the car sometimes stalled when stopping in the drive selector mode. This malfunction manifested itself on Santa Fe (CM) and ix35 equipped with a 6-speed automatic gearbox. In all cases, the valve body was to blame. In the box, only the torque converter (donut) can turn off the engine. To diagnose, you need to understand how it works. At idle, it sends little torque to the gearbox, so the engine doesn't stall. To save fuel, modern torque converters have a lock - a friction disc built into the torque converter. Blocking on most cars starts to work only at higher speeds (4,5,6 speed). If you turn on the lock on a stationary car in D mode, then this is tantamount to throwing the clutch on a manual transmission. Possible reasons: 1. Electrical part. The torque converter lock is activated using the automatic transmission electronic control unit. To exclude from suspicion the wiring and the automatic transmission control unit, it is enough to disconnect the connector from the gearbox. The gearbox without electrical power will go into emergency mode. When switched to D mode, 4th gear is engaged. My machine being diagnosed continued to stall and I understood that the breakdown was inside the automatic transmission. In general, diagnostics can be carried out using error code P0741.2. Checking the hydraulic part. Torque converter lock-up control pressure must be measured. These are the DA and DR ports.

It is advisable to use two pressure gauges, but one can be dispensed with. You can see what should happen in the documentation for error P0741:

As we can see DR = 7.3 DA = 4.4. The important point here is that DR is larger than DA and, therefore, the lock disc will not be pressed against the fluid coupling housing. When I took measurements, I got the value that, on the contrary, DA is greater than DR. and hence the lock was on. The following figure clearly shows how the blocking works.

Based on the information received, I removed the valve body and washed it. When washing the hydraulic unit, pay special attention to the blocking solenoid valve. You can briefly apply voltage to click and rinse. The valve body must be completely disassembled and washed in diesel fuel. Nothing else can be used for flushing. Extreme care must be taken when tightening the valve body bolts. Overstretching also causes problems later.

Ideally, of course, I would change the filter, but for this you need to remove the box and disassemble it.

There is still a possibility of destruction of the torque converter inside, but this is extremely unlikely and I have not encountered such a defect.

Hydroblock washing

www.diagnoz-auto.ru

Does the car stall while driving? All causes and consequences!

Most drivers do not know why the car stalls while driving. The problem is quite common and very annoying, given that a car can stall at any time, especially if the driver has already entered a busy road.

This problem in such a situation interferes with both the owner of the car and road users. From the outside, it may seem that the driver simply did not learn how to drive properly.

If such a malfunction occurred only a few times, and then disappeared without a trace, everything is not so scary. But if the engine tends to constantly stall right while driving, this is already a serious problem. Do not forget that such sudden stops are dangerous on the roads, a more inexperienced driver may simply not have time to stop, which will lead to an accident.

Main reasons

Engine stalls:

At the moment of gear shifting, as well as at neutral speed.
While pressing on the gas.
When engine speed drops.

It is worth noting that the causes of malfunctions are usually different for an injection and carburetor engine. Also important is the factor at what time the engine stalls: cold or hot.

The reasons may be the following:

Poor quality gasoline. Engine failure can occur due to low-quality fuel refueling. Any knowledgeable driver will ponder when and where the last refueling was made. There are cases when, after refueling at another station or with a different brand of fuel, the car starts to stall while driving.
Faulty spark plugs. If, while driving, along with a sharp stop of the engine, the car makes sharp movements in the form of jerks, it starts poorly, then the reason is in the candles.
Fuel filter. Another reason for the malfunction is a dirty fuel filter. Over time, when passing the fuel mixture, the filter becomes clogged with waste. If it is faulty, it should be replaced.
Why the car stalls on the go - the reason is a faulty fuel pump. With this malfunction, the fuel cannot normally enter the aggregate system, in this case, you just need to replace the pump.
The battery must be kept clean, the terminals must be cleaned in time, because without proper care they either oxidize or become clogged.
The generator is a very serious and important part of the car. When it malfunctions, the entire energy consumption falls on the battery, which, without the support of the generator, can be discharged very quickly, and the car will not just stall, but will stand somewhere in the middle of the road until it receives a charge.
Air filter. When it is contaminated, a failure occurs in the timely enrichment of the fuel mixture. Very often, car owners forget about the timely filter change, which leads to malfunctions and breakdowns.
Optional equipment. With a large number of installed additional parts that bring comfort to the owner, a huge amount of energy is consumed. The machine starts to stall because it is not getting enough charge to run normally.

In the case of a stalled engine at the very beginning of work, when the car has not yet warmed up and the engine is not hot, there may be such problems:

Faulty air-fuel mixture supply system.
Auto throttle defective or incorrectly adjusted.
Thermostat malfunction - in the event of a breakdown of this part, the motor will not be able to warm up normally and give the necessary speed.
Fuel injectors are heavily soiled.
The coolant sensor is broken.

There can be a lot of reasons for a breakdown, and special diagnostics, which are carried out only in car services, can correctly determine the cause. Only after that should the repair of the machine begin. Having learned what the problem is, it is easier and faster to repair the car.

On vehicles with an automatic transmission, the automatic transmission sensor may light up while driving, and then the car stalls.

In this case, the automatic transmission should be diagnosed. Repair of such a malfunction should be entrusted to specialists. Usually, in car services, immediately after the diagnosis, at the request of the driver, the auto mechanic disassembles and sorts out the box and troubleshoots. Usually the box does not need to be completely replaced.

injection engines

If a car with an injection engine stalls while driving, then there may be several problems of this kind:

The system of enrichment of the fuel mixture with oxygen is faulty.
Broken oxygen sensor.
The intake manifold is malfunctioning.
Fuel injectors partially or completely dirty.
The cooling system of the unit is broken.

If the owner himself is not sure of the cause of the breakdown, the same diagnostics are needed, after which repairs are already underway.

You can describe some of the reasons in more detail, but do not forget that there can be a lot of them, and they are all different - it depends on the brand of the car, the country of manufacture, the type of engine, etc.

Spark plug

According to statistics, the reason for the large number of cases of a stalled engine is precisely in the spark plugs: they simply do not spark. Spark plugs may be dirty, coated, or a malfunction occurred when voltage was applied directly to the spark plug.

In any case, if the breakdown is due to candles, the car will twitch while driving. For example, if there is dirt on the contacts of the candle, then the problem is the low quality of the fuel mixture or the malfunctioning of the oil supply systems, or oil splashes are found on the candles, which indicates that there has been a serious breakdown in the component cylinders of the engine. For an accurate determination, you need a complete examination of the engine in a car service.

If you delay the repair, you can get a lot of problems, since you will have to replace the entire set of pistons.

If a red-brown coating is found on the spark plugs, then the problem is the constant use of low-quality gasoline. It is worth replacing the candles with new ones, changing the gas station with better gasoline. But if this does not help, then you need to look for a wiring malfunction.

In the case of power supply, the following malfunctions occur:

When installing a new battery, the terminals are poorly fixed.
Breakdown of high voltage wiring.
Faulty generator.

High-voltage wires in the event of a malfunction are completely replaced. For good contact between the battery and the terminals, you need to clean them with sandpaper. If the malfunction is in the generator, then it can be in the event of a broken timing belt, as well as a malfunction inside the unit itself. Generator breakdowns are easier to detect, since there is a special icon on the dashboard that lights up in case of any deviations.

Additionally

Brake failure. In this case, the design of the vacuum amplifier is usually faulty. The problem comes to light at sharp braking - as a result, the stalling engine (i.e. slowly stalls by itself). Usually the entire amplifier is changed, or its adjustment.
Exhaust system. The exhaust system can be contaminated, and after such contamination, the car simply cannot “spit out” all the accumulated gas, and begins to “choke”. It is necessary to clean the muffler, if the problem is not only pollution, but also a breakdown of the catalyst, the exhaust system must be completely replaced.

The reason is the low quality of the fuel? Often the problem is in low-quality fuel, or inappropriate for the brand of car that the driver drives.

Gas stations need to be carefully monitored.

Fuel tends to pollute, contribute to the rapid wear of many vital parts for a car.

When using low-quality mixtures, the following occurs:

Rapid contamination of the fuel filter.
There are malfunctions in the operation of the injector nozzles.
Throttle valves get dirty quickly.
The fuel pump is malfunctioning.

The most important indicator of a malfunction is a smooth decrease in engine power, as a result of which the car will stall even when the gas pedal is pressed sharply. Many problems can be identified by yourself without spending extra money to pay for the services of a service center, but if the problem is not resolved during an external examination and subsequent repair of fuel systems, you will have to carry out computer diagnostics for a more complete and in-depth identification of problems.

If an automatic transmission is installed on the machine and the machine periodically stalls while driving, then the malfunction is usually in the power supply.

When the gearbox changes gear, the computer receives an alert about a malfunction of some part and decides to immediately turn off the engine. Problems with this type of car must be solved as quickly as possible, without fail, repairs should be carried out only by specialists. Personal interference will lead to an even greater problem.

So, the car stalled while driving, what to do next:

Using the inertia of the movement, push the car off the roadway, no matter if it is a city road or a highway.
Enable alarm.
It is mandatory to install an emergency sign at the back of the car: there are enough fans of high-speed driving everywhere, you should not create an emergency.
Put the car on the handbrake.

Options for the development of further events 2:

Do your own repairs.
Find a way to transport the car to the service.

In order to avoid such unpleasant and unexpected moments when the car stalled on the go, you need to follow simple rules:

As often as possible, carry out diagnostics of the car in a service center.
Carry out preventive maintenance and inspection of the machine on your own.
Monitor the condition of parts and replace them in time so that the machine does not break down in unexpected places.

You should always have a tool with you to fix minor breakdowns, as well as a can of gasoline in order to avoid stopping due to its absence.

Often, car owners are faced with a very unpleasant problem: a car on the go suddenly stalls. Then immediately, perhaps after a certain time, it starts up again and rides as if nothing had happened. Such malfunctions at service stations belong to the class of flickering malfunctions, many workshops charge double the cost for their repair. And this is understandable: it can be difficult to detect. After all, as a rule, the so-called general effect works in reverse here. If an auto electrician comes to such a call, then the car starts up as if nothing had happened, and works until the master leaves. I myself have been in such situations many times. First, let's figure out, in general, what is needed for the operation of the engine.

Conditions for normal engine operation

In internal combustion engines, stable operation requires:

constant air injection, moreover, in the proportion corresponding to the fuel;
optimal rail pressure;
normally working nozzles (injectors);
correct ignition angle;
serviceable sensors and actuators of the engine control unit;
required compression;
in gasoline cars - plus an ignition spark.

In the language of motorists, an engine needs air, fuel, compression and ignition.

From the point of view of the probability of failure of the internal combustion engine, gasoline engines are more vulnerable, because they have an additional system - a high-voltage ignition unit, which is very sensitive to weather conditions. Drivers know that the diesel engine has only to be started, and it can “babble” all day long, though not always.

Why does it happen that the car stalls, then starts? The most likely causes of this failure include:

1. Immobilizer problems

The immobilizer for most motorists is a great danger. And this is understandable: you can’t deal with it without special equipment, and the services of auto electricians to fix problems with immo are expensive. If for some reason the immobilizer blocks the engine control unit, then different car models behave differently. In BMW, in case of problems with the immobilizer, the starter usually does not even spin, most models allow you to torture yourself to start. But in Renault, as in some other models, the engine usually starts, but after a few seconds it stalls. Then it starts up again, and after the same time it stalls. This could go on ad infinitum.

Immobilizer synchronization failure occurs for the following reasons:

use of a non-native key or loss of a chip from it;
discharge of the battery in the key, if the circuit provides power to the chip;
breakage of the pumping loop (located in the area of the lock larva);
car alarm failures with auto start (transponder);
malfunctions in the power circuits of the engine control unit, immo.

Just in case, you can check if your key has a chip.

If an on-board computer is installed in your car, the immobilizer failure will be notified in the form of a message such as IMMO or SECRET SERVICE, KEY or a blinking yellow LED. It should be remembered that if you started the car and drove it for several hundred meters, the immobilizer has already synchronized with the engine control unit, its sudden stop will not be in any way related to this problem. That is: stopping the engine while driving is not an immobilizer problem!

2. Malfunction of the crankshaft sensor

It is responsible for overall ignition timing in both gasoline and diesel engines. If the sensor is faulty, then in 95% of cases the car will not start at all. But, if the sensor is on the verge of its performance, then the engine may fail. The fact is that the sensor is usually electromagnetic. It represents an inductor wound with an extremely thin wire around a magnetic core. During operation and wear, moisture can get into it. When the engine heats up while driving, the coils of the sensor can open and the engine stalls. Then, as you struggle to start it, the engine cools down, the coils of the sensor close again, and the car starts like it should. So: a typical situation of a faulty crankshaft sensor: the engine starts cold without problems, after about 15 minutes of movement it suddenly stalls, then, after you wander around the car for half an hour, it starts again without problems. Tip for motorists - moisten a rag with cold water and put it on the sensor. Somehow you will reach the house while the sensor is cooling.

By the way, this malfunction may not be diagnosed on a cold one.

3. Malfunction of the flow meter

This sensor is involved in the qualitative formation of the mixture. If the flow meter is clogged (this often happens on idle engines, it becomes clogged with oil), the mixture is enriched, it can fill the candles. At idle in traffic jams or when coasting, this can cause the engine to stop. Then, with difficulty, the engine starts again, and so on. You can try cleaning the flow meter with a carburetor cleaner. Many motorists turn it off altogether and, if the car stops stalling, they ride like this for a couple of years.

Installing a new flow meter to replace a heavily contaminated old one solves the problem for a short time. If the piston group or valve stem seals are heavily worn, the sensor will soon become dirty again.

4. Ignition system of gasoline internal combustion engines

If one of the spark plugs is flooded or one of the high voltage wires is pierced, the engine usually does not stop. But if the ignition coil (if it is single or dual) breaks through when heated, the car may stall periodically, then start again after a while. Sometimes the coil has microcracks. In wet weather, moisture can get in there and the car can suddenly stop. Sometimes in a downpour or when it gets into a puddle, the ignition system is flooded with rainwater. Then, as it dries, everything returns to normal. There is only one way to check the ignition coil: throw in a known-good one, because a broken coil can ring normally with a multimeter.

5. Idle speed controller

If the idle speed is not adjusted correctly, or the regulator drive sticks, the engine may stop at idle speed. Bypass regulators and regulators with stepper motors can be tried to be cleaned.

6. Air suction

Usually leads to uneven engine operation, which can stall with a sharp movement of the accelerator pedal. Many service stations use smoke machines to search for leaks. Experienced minders use a good cigarette.

7. High pressure pump wear

If there is a suspicion of a fuel pump, it is better to remove it and take it for diagnostics.

8. Low rail pressure

Typically, engine shutdown occurs due to the electronic valve pressure regulator installed in the fuel pump. As a rule, flushing the valve does nothing.

9. Fuel pump wear

In many situations, the fuel pump remains in a visually working condition, that is, it seems to be pumping. But its performance and pressure drops to critical values. The impeller starts to pump, then the pressure decreases by an order of magnitude. The car moves and then shuts up. Change the fuel pump without question. Now the pumps themselves are inexpensive, they can be replaced without tooling, which costs money.

10. Car alarm failures

Frequent malfunction. If the alarm is installed by a non-professional, even worse, in garages, it can start to fail immediately. After 7 years of operation, all alarms begin to fail. Typically, signalers use fuel pump circuits to block theft. If the signaling fails, the fuel is cut off. Now it has generally become fashionable not to set alarms, but to turn them off. There are more and more such calls to service stations. Tip: install the alarm only at proven service stations, otherwise you won’t find the ends in a couple of years; when buying a used car, find out the coordinates of who installed the car alarm.

If your car began to periodically stall while driving, then start, immediately solve the problem, determine the cause of the malfunction and fix it. Otherwise, sooner or later it will die out for a long time.

Read about troubleshooting other problems.

This article will talk about why the car stalls on the go. The reason for this phenomenon may be the most banal, but you will get a lot of trouble from such a "behavior" of the car. In addition, the engine may stall at idle. There is little pleasant in this, the motor seems to start, but after a while it stops working. It is possible that the engine does not want to start if its temperature is close to the operating temperature. The operating temperature of the engine is about 90 degrees. And there can be many reasons, but you need to consider the main ones.

Most common cause

It is worth paying attention to the fact that all the reasons can be divided into several categories. Why does the car stall while driving? The reason can be both banal and complex. If we are talking about injection engines, then very often the regulator that is responsible for the speed fails. It is he who supplies the required amount of air to the fuel rail. The idle speed controller is a stepper electric motor, with its help, the channel opens and closes, through which clean air flows into the mixture formation ramp. So, first of all, you need to make sure that the idle speed regulator is working. To do this, turn the crankshaft with a starter, at the same time depress the gas pedal. The motor starts, but the number of revolutions is constantly changing. There is a breakdown of the IAC - the engine stalls when you press the gas. And the most effective way to get rid of such a nuisance is to completely replace the element. You need to install a new one. On VAZ cars, this is done literally in a matter of minutes.

Throttle problems

Quite often, the cause of the engine starting to stall is the throttle itself. It is possible that the air filter has worn out, so the entire surface of the damper is contaminated inside. To fix this breakdown, it is enough to clean the damper completely from the inside. Please note that after a thorough cleaning, the problem may persist, still the engine stalls when you press the gas. In this case, you must make sure that the position sensor is in good condition. This sensor is a variable resistor. It is installed on the damper axis. Moreover, the maximum wear is observed in the extreme position (corresponding to the idle speed). If it fails, it must be completely replaced. The cost of the part is quite low, and the replacement takes place literally in a matter of minutes. But it is possible that the motor starts to stall, despite the fact that all sensors are in perfect condition.

Fuel quality

Always keep an eye on what kind of gasoline you fill your car with. In most cases, all of the above symptoms appear as soon as you fill the tank with fuel. Of course, the engine may stall after a while. Therefore, it will be difficult to immediately determine the breakdown. It is also worth paying attention: the reason that the engine starts to triple, stall, should always be looked for in gasoline itself. To cure such a "disease", you will need to completely drain the gas from the tank, as well as replace the fuel filter. Unfortunately, at gas stations you do not always buy high-quality fuel. Therefore, it is worth choosing one brand of a manufacturer that sells the highest quality gasoline. Of course, there are times when the car stalls on the move (the reason for this lies not in gasoline). Please note that an excessively low cost is the first sign that gasoline is of dubious origin. And pouring it into the tank is tantamount to sending a car at full speed into a pole.

Spark plug

To make sure that they are working, you need to unscrew them all, check the gap, as well as the presence of soot. And your car stalls while driving. The reason may be hidden in the candles. In the event that there is a strong deposit, but the gap is within the permissible values, it is necessary to clean the electrodes of the candles. But the best way out is to install new candles. In the same case, if the gap is very large, there is excessive wear of the electrode, cleaning will not help, it is necessary to completely replace the set of candles.

Fuel filter

And here is another very common reason for which the car stalls on the move. VAZ or foreign car - it doesn't matter. But this is especially true for older cars. Some drivers simply forget that the car has a gasoline filter. It is located at the bottom of the fuel pump. Of course, if there is dirt in the filter, gasoline will not enter the fuel rail and the combustion chamber simply will not. There will definitely be interruptions in the supply of fuel. At the same time, by pressing the gas pedal, turn off the engine. To get rid of this malfunction, it is necessary to remove the gasoline pump, replace the filter. It is also worth considering that the tank itself can cause an early clogging of the filter. Therefore, either a replacement container or a thorough cleaning can help.

Air filter

A similar situation, as in the case of a gasoline filter element. Please note that the operation and repair of the vehicle must be carried out in accordance with the requirements of the manufacturer. After all, you know that a mixture of gasoline and air is supplied to the combustion chamber. Therefore, if any component of this mixture does not enter the fuel rail, the engine will stall. Consider an example of how a motor works when there is not enough air. Too much gets into the combustion chamber, as a result of which candles are poured. This makes it feel like the engine is choking. Among other things, some motorists who do not know about the principle of operation of an internal combustion engine can cover the inlet pipe with a rag so that water does not get into it. It's funny, but it happens.

Fuel pump

If that, of course, the car stalls. At the same time, the carburetor will work perfectly, but no one gives it gasoline. On injection vehicles, the fuel pump is located under the rear seat. On carburetor - near the camshaft (since it has a drive from it). If it stops working, then the engine may idle normally, but when the speed increases, it will surely stall. However, if the gasoline pump is completely worn out, the engine will not start at all. To get rid of this malfunction, it is necessary either to repair the pump, or to replace it completely, which is most effective. As for carburetor motors, the pump diaphragm drive rod can be very worn out in them.

electrical equipment

The problem of stopping the motor can also be a malfunction of electrical equipment. In particular, the appearance of oxidation on the batteries may occur. Even old cars, even new ones - everyone needs maintenance and careful care. Consequently, the contact worsens as the resistance increases, and this leads to the fact that the engine stalls. The battery itself may also fail. In the same case, if the generator does not produce the required current, the entire electrical network of the car switches to battery power. If you do not immediately see a burning lamp, signaling that there is no charge, the car will continue to move. Given that the light will be on, and the ignition system is working, after a while the battery will be completely discharged and the engine will stop. You will have to charge the battery, as well as completely repair the generator.