Foreign cars sold in Russia are often equipped with an automatic transmission. Such a unit is much more convenient and comfortable, especially when driving around the city. Usually, automatic transmissions have a fairly large resource and, with timely and competent service, can work for a very long time. Almost all malfunctions occur due to the fault of the owners themselves, who do not understand the peculiarities of the maintenance of automatic transmissions.

Peculiarities

Japanese automatic transmissions (Toyota Corolla is also equipped with it) - one of the most reliable. In Russia, you can still see old "Crowns" and "Marks" with their own and even never repaired transmission, despite the fact that they are already in their third decade.

It should be noted that some modern automatic transmission models, which are installed on luxury modifications of Toyota and Lexus, do not require maintenance. This, of course, does not mean that automatic transmission oil (including Toyota Crown) does not need to be changed at all. And many do so. The fluid resource is no more than 60 thousand kilometers. Further, the oil begins to blacken and loses its protective properties. But this is not the only factor affecting the resource. Unfortunately, the current trend towards more sophisticated design leads to a decrease in reliability.

Major problems and malfunctions

Typical problems with are largely similar for different brands, including automatic transmissions (Toyota Mark-2 is no exception):

1. Decrease in the oil level in the box, which is caused by a violation of the integrity of the block and the gearbox pipes. The culprit may be burnt gaskets, old cracked pipes. Check the oil level and top up if necessary. It should be noted that the oil for manual transmissions is in no way subject to operation on automatic transmissions due to its higher viscosity.
2. All gears are not included, except for the reverse, or vice versa. This is due to wear on the clutches or the clutch itself. To eliminate, of course, you will have to remove the box and open it, making a visual inspection.
3. It happens that the third and fourth gears are not included. The reason for this may be wear on the clutches, breakage of the piston cuff or damage to the splines.
4. Gears are not included, the car is stationary. There may be several reasons for this. This is an insufficient oil level, wear of clutches and their pistons, a breakdown of the clutch.
5. Slip when starting off - wear of the torque converter shaft or malfunction
6. Car movement in neutral position - sticking of the shift piston, connection of discs due to overheating. Sometimes the adjustment of the shift lever is disturbed.
7. Engaging the transfer and starting the car from a place only after warming up. Here, most likely, there is wear on the clutches, which do not provide the transmission of torque.

Features of automatic transmission operation

When operating an automatic transmission, first of all, you need to monitor the radiator, do not allow it to become dirty.

It must be remembered that the automatic transmission heats up during operation, and when driving off-road, an additional radiator is often needed. Damage to the cooling system can cause the oil to overheat. As a result, burning of the O-rings and clutches. Thus, compliance with the temperature regime of the automatic transmission is one of the most important conditions for a trouble-free ride.

Features of selection and replacement of oil

Designed so that the quality and lubricating properties of the oil are the most important factors affecting its durability. Any deviation from the norms can be detrimental to the unit. Therefore, it is so important to comply with the oil change table for a specific model.

Aisin automatic transmission malfunctions

The supplier for these vehicles for many years has been the company Aisin, which specializes exclusively in these vehicle units. But, in accordance with the trends of the times, the simple design of these boxes is a thing of the past.

New multistage units with complex control algorithms and a switching system have appeared. But, as in any mechanism, the complication of the design entails a decrease in reliability. Unfortunately, Toyota's automatic transmission also has typical illnesses.

Toyota Rav-4

These SUVs are fitted with a U140 series gearbox (not to be confused with the one on the Camry). This unit is deservedly popular due to its durability and reliability. But there is also a weak point here - electronics. This series is equipped with electronic breakage protection. When turned on, it blocks the operation of the unit completely. This is treated by replacing the electronic control unit.

"Toyota Corolla"

This model, not only is one of the oldest in the Toyota model range, but it is also the most reliable. The most common automatic transmission (Toyota Corolla is also popular thanks to it) is the 4-speed transmission of the U341F series, which has already earned itself the highest reputation. But sometimes breakdowns occur in it.

The main ailment is the failure of the hydraulic plate, which entails the replacement of the gearbox solenoid block. For the latest generations of this model, Toyota is installing a "robot". These are manual transmissions with automatic electronic control. In such units, the clutch is controlled by a separate unit, which, in case of malfunction or partial breakdown, gives commands for frequent engagement and disengagement of the clutch.

This leads to slippage. The electronic control unit can be replaced and you should be fine. However, if this is not done in a timely manner, the clutch itself will need to be repaired, since multiple on-off switches do not contribute to the durability of this unit in any way.

Automatic car "Toyota Camry"

The first generations of "Camry" were completed with the A540E series gearbox.

This model has gone through several modifications during its production. Moreover, they are rarely interchangeable: the same units, depending on the year of manufacture, are completely different. This gearbox is quite rare in Russia. And in the event of a breakdown, serious problems with spare parts can arise. The new generations of Toyota Camry are equipped with automatic transmissions U140E and U240E. The first is for 2.4 liter engines, the second is for 3 liter engines. The weaker U140E is poorly adapted to the lower weight of the car and, as a result, cannot boast of high reliability. A frequent breakdown on it is the failure of the back cover. This leads to burning of the clutches, increased engine speed and breakdown of the automatic transmission torque converter.

"Toyota Camry" with a more powerful internal combustion engine is equipped with wear-resistant gearboxes that break less. However, there are problems with the back cover. In addition, there are isolated cases of failure of the control electronics.

Conclusion

As you can see, there are quite a few automatic transmission malfunctions, and although they are often of the same type, this does not mean that you should ignore the incomprehensible and non-standard behavior of the transmission. Never put off figuring out the reasons "for later". Replacing the automatic transmission (Toyota Camry is no exception) can result in a very large sum. Therefore, it is important to maintain the technical condition of this unit in good condition and carry out regular maintenance. After every 150 thousand kilometers, the box must be completely flushed. This is done on a specialized stand under pressure. This is the only way to remove waste and metal shavings.

There are many myths about the types of breakdowns in automatic transmissions today. Indeed, some types of automatic transmissions can hardly be called reliable.

Inexperienced driving, mistakes in switching, heavy operation against the background of far from the best roads in Russia - all this negatively affects the condition of the "automatic machine" and the timing of its life.

In this article, we will briefly deal with the design features of the automatic transmission, the main problems, their symptoms and the subtleties of elimination. In general, more about everything.

We will not delve deeply into the design features of an automatic transmission - we will only mention them briefly.

So, there are five main elements in total:

1. The gearbox itself with a set of gearboxes;
2. Hydraulic transformer (plays the role of a conventional clutch);
3. Gear shifting mechanism (friction clutches, brake band and other elements);
4. Distribution block (through it, oil is supplied to the hydraulic pushers, which "push" the gear selection mechanism).
5. There is also an automatic transmission control unit - this is the main computer of the car. Its task is to set in motion the hydraulic part based on the readings of the vehicle sensors.

Automatic transmission malfunctions

Now let's move on to the main automatic transmission malfunctions.

The situation is painfully banal and vital. The car suddenly starts to junk, and the automatic transmission malfunction lamp lights up on the electronic board.

In such a situation, there is no need to worry or panic, because problems with electronics can become the source of problems.

Naturally, in such a situation, the control unit has no choice but to turn on the automatic transmission emergency mode.

When such a signal appears, it is impossible to work with the box until it is completely repaired. The only hope is to somehow get to the car service.

What kind of malfunctions in the automatic transmission can occur?

There are several of them.

Breakdown of the automatic transmission control unit - is determined by the constant burning of the emergency mode lamp. Computer diagnostics will help to identify the problem.

A trial replacement of the assembly is often necessary (this service can cost about a thousand rubles).

If the control unit fails, replacement is ideal, but it is costly.

Depending on the type of car, the price can range from 10 to 50 thousand rubles. You will also have to pay for the installation. Sometimes ordinary repairs can help out, for which they ask from 5 to 10 thousand rubles. But, unfortunately, renovation work does not always help.

Breakage of one of the sensors (ABS, camshaft, throttle valve, air flow).

In this case, the emergency mode lamp does not light up constantly, but only during acceleration and deceleration of the vehicle.

Determining such a breakdown is elementary - using the standard one. The cost of the work is about 3 thousand rubles.

It is not always possible to eliminate the malfunction by repair - more often the replacement of the sensor saves. The only problem is the high cost of parts, because just one sensor can cost from 5 thousand rubles.

But if the money was found, then the repair work itself does not cause problems - it takes no more than two hours. The cost of replacement largely depends on the service, but most often it is necessary to shell out an amount from a thousand to one and a half thousand rubles.

Bad contacts or wiring.

Bad contacts or wiring. Here, the cause can be anything - wire breaks, oxidation of contacts, short circuits, and so on.

In the event of such a malfunction, the emergency mode lamp lights up chaotically - without any logic. Sometimes it can burn continuously or not ignite at all for a long time.

There is one way to diagnose a malfunction - by mechanically searching for a bad contact or an open circuit. To do this, it is enough to inspect and, if necessary, "ring" the wiring.

The work is time consuming, unpleasant and costly. In car services, they may ask for this from 10,000 rubles or more, because sometimes you have to get all the wiring.

Those who have dealt with this issue at least once know how much needs to be removed in the car.

The main thing in this business is to quickly find the place of damage and eliminate the malfunction. Sometimes it all ends with the replacement of a contact or a piece of wire, which costs a maximum of one to two thousand rubles.

If it is necessary to make a complete replacement of the wiring, then the costs may be more significant - from 30,000 rubles and more.

Shaft rotation sensor "machine".

Breakage of the "machine" shaft rotation sensor (input or output). Determining the problem is simple. The emergency gang light comes on when the automatic transmission handle is moved to position D.

Sometimes a signal may appear the first time the handle is moved to any position. Such a malfunction is easily detected by conventional computer diagnostics.

The sensor cannot be repaired. The best option is a replacement, which takes hours. The cost of the work will result in an amount of 5 thousand rubles and more.

Breakdown of the "machine" solenoid.

Breakdown of the solenoid "machine" or electronic pressure regulators. In this case, the automatic transmission malfunction lamp may not light up or light up not in all modes (with some switching).

But on the mechanical side, everything becomes clear. Gears may not turn on, severe slippage or impacts appear.

Diagnostics gives answers to many questions. If more accuracy is required, then a number of basic parameters can be measured, for example, inductance or circuit resistance. Such work costs from 5 thousand rubles.

Most often, replacing a faulty solenoid or pressure regulator helps out. If you have to change the entire unit, then the costs are quite serious - from 20 to 30 thousand rubles. It is often impractical to repair a block, because it can be more expensive than buying a new one.

Breakage of the oil temperature sensor.

Breakage of the oil temperature sensor. In case of such a malfunction, the "automatic" box can go into emergency mode either after the oil has warmed up, or immediately after the car is factory.

A problem is identified in computer diagnostics. The only way out is replacement. One sensor costs up to 5 thousand rubles.

Many new car buyers prefer vehicles equipped. This is due to the convenience and ease of control of the automatic transmission. The driver just needs to choose the most suitable mode, in accordance with the conditions of the trip, and the "smart" box will independently switch speeds. During the operation of a car, the transmission takes on huge loads. Therefore, violations of operating conditions can cause numerous automatic transmission malfunctions that require subsequent repair.

Symptoms of automatic transmission malfunction

Well-known automotive corporations are making every effort to create new models with an extended service life. Advanced technologies are used in the development of modern automatic transmissions with increased reliability and durability. According to the designers, the first major repairs should be carried out no earlier than 150 thousand kilometers.

Depending on the nature of the automatic transmission malfunctions, various symptoms appear:

1. The inability of the vehicle to move in any direction.
2. Shocks occurring when the vehicle is moving.
3. Non-standard sounds, tapping, automatic transmission when the box is running.
4. Inability to change gears.

For example, if the automatic transmission torque converter breaks down, when changing to another gear, the car moves in jerks. The severity of the breakdown of the automatic transmission is reflected in the degree of its manifestation. Experienced drivers know that transmission malfunctions while the vehicle is moving do not disappear by themselves, but progress rapidly. Each defect in the automatic transmission must be localized and eliminated in time, otherwise, soon it will be necessary to spend money on overhaul of the transmission and the entire machine.

Restoration and repair work should be carried out by highly qualified specialists. Only they have access to professional diagnostics, as a result of which the real cause of malfunctions in the functioning of the automatic transmission is determined.

Important: If the machine has failed during the trip, while the gears are not shifted, they are blocked, you need to call a tow truck. It is strictly forbidden to continue driving a vehicle with a broken transmission, otherwise the transmission drive will be seriously damaged.

To make it easier for drivers to find the place where the failure occurred, the developers have included additional sensors in the automatic transmission design. With their help, you can approximately establish the probable cause of the box failure:

• reduced transmission level;
• temperature rise in the lubrication system (box overheating), etc.

Preliminary diagnostics of breakdowns based on the readings of sensors does not give complete confidence in the correct determination of the location of the defect. An accurate diagnosis can be made only after disassembling the automatic transmission and visual inspection of the transmission.

Automatic transmission - malfunctions and their elimination

Most often, in automatic transmission you can find breakdowns of the following nature:

1. Difficulties in transferring the selector to the intended mode, caused by defects in the wings.
2. The occurrence of oil drips and, accordingly, a decrease in the level.
3. Incorrect gear shifting due to automatic transmission malfunctions.

In old models of cars with an installed automatic gearbox, there is a direct mechanical connection between the lever and the transmission - the selector wheel. In case of poor movement of the selector in the link, you just need to replace the deformed link and the outdated lever with new devices. Thanks to the good location of the problem node, the wizard has convenient access. To replace a worn-out mechanism, you do not have to dismantle the gearbox, which will greatly facilitate the restoration of the backstage performance.

Traces of leaking grease on the body part are a clear indication of automatic transmission malfunctions. If such signs appear, it is safe to say that the sealing elements are completely worn out. Replacing oil seals and gaskets is not difficult and is quite accessible for independent conduct. A visual check for oil leaks is required after every 2,000 km.

If, instead of the usual behavior of the box, the gears are switched during the period of high or low speeds, the automatic machine may soon be blocked. The reason is a malfunction of the automatic transmission control unit. When the first signs of a malfunction of the automatic transmission appear, it is necessary to carefully inspect the electrical part of the automatic transmission, eliminate the identified damage and replace the problem mechanism.

What will help to avoid typical automatic transmission malfunctions

It is known that the automatic transmission is a complex mechanism. The main symptoms of an automatic transmission malfunction arise due to the following adverse factors:

• violation of the recommended transmission oil;
• overheating of working parts and assemblies of the automatic box;
• automatic transmission oil starvation;
• an increase in frictional forces between the mating metal elements of the box;
• abrasion and deformation of working surfaces;
• sticking of the valve body solenoid valves - automatic transmission solenoids.

To get close to the failed solenoids and replace them with a new set of valves, you will have to dismantle the automatic transmission from the car.

With the onset of winter cold weather, the lubricant, as well as working parts and automatic transmission units, need to be thoroughly warmed up. If, at negative ambient temperatures, the vehicle starts moving without preliminary warming up the gearbox, the conditions for the normal mobility of the transmission elements will be violated. Due to the frequent use of aggressive driving style, typical automatic transmission malfunctions appear:

1. Accelerated combustion of the friction linings of the clutch discs, due to the increased speed of the secondary shaft of the automatic transmission.
2. Under the influence of ultra-high temperatures and pressure inside the automatic gearbox, ATF transmission oil loses its useful lubricating properties.
3. Difficulty shifting gears.
4. Incorrect response of the automatic transmission to the control actions of the selector.
5. Increased wear of the support bearings of the shafts, gears of the automatic gearbox.
6. Valve body functions malfunction due to.

To increase the operating life of the automatic transmission and the entire transmission, it is necessary to smoothly act on the control lever when changing gears, without sudden movements. In order to avoid increased loads on the elements of the power unit of the car and the automatic gearbox, do not sharply press the gas pedal into the floor.

The basics of correct inspection of the automatic box

With certain technical skills, it is not at all difficult to directly replace parts that have failed. The main difficulties and difficulties that car mechanics face begin with providing access to problematic parts and components. It often happens that the entire gearbox needs to be removed from the vehicle. This procedure is possible only with the use of special lifting devices.

After removing the machine, the masters open the box case, disassemble it and determine the place and nature of the malfunction. To eliminate the identified breakdown, experts perform cleaning, high-quality repairs or complete replacement of a part or automatic transmission unit that is out of order. While the box is disassembled, a thorough examination and diagnostics of the following automatic transmission systems and mechanisms are additionally performed:

• soft friction discs of the clutch mechanisms of each gear;
• hydraulic system solenoids;
• hydraulic plate oil channels, etc.

Simultaneously with the repair and restoration work, an examination of the sealing elements of the box is carried out, a complete replacement of the ATF lubricant, as well as the oil and air filters.

Typical malfunctions of the automatic transmission and methods of their elimination

Among the most common problems with automatic transmission, the following points can be highlighted:

1. Unusual sounds and noises in the box.
2. Automatic transmission slipping.
3. Vibrations in the area of ​​the box are automatic.
4. Gear shifting problems.
5. A noticeable decrease in the level of transmission oil in the automatic transmission.
6. Overheating of the box.

When the initial signs of malfunction appear, it is recommended to send the machine to the nearest service center. Prolonged operation of a vehicle equipped with an automatic transmission that has deviations from the usual behavior will lead to a stop of a car with a locked gearbox. To the material costs of repairing a broken car, additional costs of paying for expensive tow truck services will be added.

Table of the most common automatic transmission faults:

Typical breakdowns of the automatic box	Causes and methods of elimination of identified defects
Vehicle slippage at first speed. The rest of the transmissions are working properly.	Replace the first clutch piston ring and seal. Clean the converter valve from harmful deposits.
The box works only in first gear. When switching to others, including the rear, the automatic transmission does not work.	Replace friction discs and worn clutch pistons. If the sealing elements break, the coupling rings should be replaced with a new part.
The car has stopped and does not budge. When trying to change gear and is pushed.	It is necessary to replace the automatic transmission torque converter. At the same time, check the volume of oil poured into the automatic box using a dipstick or a control plug. Add lubricant if necessary. The main reason is a malfunction of the oil filter, which needs to be replaced.
The box works only at the third speed.	Friction discs and clutch piston cup need to be replaced. The valve body solenoid valves are heavily soiled. If cleaning the solenoids does not give results, the car must be sent to the nearest service center. If you turn on the emergency control mode, you can detect serious damage to the automatic transmission.
The vehicle does not run in reverse.	Defects in the brake system, in particular, the brake band is worn out. It is required to inspect the system elements and eliminate the identified malfunctions in the braking system.
Inadequate vehicle response to gear changes.	Insufficient amount of transmission oil in the automatic transmission. Check the lubricant level and top up if necessary. It is required to clean from contamination: steel mesh of the oil filter, solenoids, valve body valves.
During the operation of the car, the vibrations of the automatic transmission are noticeable. With an increase in revs, the box emits a characteristic growing rumble.	Bearings need to be replaced.
Crash when shifting gears	Adjusting the throttle cable and cleaning the oil filter from contamination will help. Replacing the throttle valve.
In the process of overcoming a long rise, the car slips, the automatic transmission shifts to a lower gear.	This problem can be caused by a low level of ATF oil and a failure of the oil pump. Here it is also necessary to inspect and replace the brake system band, clutch friction discs, stabilization clutch.
When the first speed is turned on, the automatic transmission starts to slip, after acceleration, the slip stops.	Slipping of the secondary shaft of the automatic transmission. The splines of the turbine hub need to be replaced. Check the condition of the clutch piston seal.
When changing to another gear, the vehicle skips.	Cleaning the oil filter, changing the transmission oil, and the oil pump will help.
Every time the automatic transmission is shifted, incomprehensible bumps are heard.	It is necessary to change the friction discs and brake band.
Until the vehicle is warmed up, movement is normal. After heating the transmission fluid, the automatic transmission begins to slip.	Unheated thick oil compresses the clutches better; after heating, the lubricant liquefies, and the pressure force decreases. The lubricant will need to be replaced.
There is no transition to a reduced speed with a sharp impact on the gas pedal. The engine speed does not increase.	Malfunctions in the operation of the power unit. You need to seek specialized help at the service station.
Detection of metal fragments of various sizes in the car pallet.	Destruction of planetary gears. The worn gear needs to be replaced.
Foaming of ATF transmission fluid, appearance of an unnatural shade.	Penetration of water droplets into the inner cavity of the box machine. You will have to completely replace the transmission oil.
When the speed is turned on, the engine stalls, the movement of the car continues while holding the gas.	Malfunctions of the elements of the torque converter. It is necessary to replace the unit with a new one.
The presence of aluminum fragments in the pallet of the car.	Failure of the "planetary" aluminum gear, sliding bearing. Dismantling and installation of new parts will be required.
Shards of plastic parts.	It is necessary to inspect all elements of the automatic transmission made of plastic.
The appearance of a characteristic metallic grinding sound while driving.	It is necessary to replace worn bearings, gear wheels of the differential mechanism.
In the pallet of the car, rollers were found that fell out of the bearing.	A damaged roller bearing needs to be replaced.

Automatic transmission malfunctions related to electronics

In the operation of the elements of the electronic control system of the automatic transmission, breakdowns and malfunctions also occur. Unlike the mechanical part, their detection and elimination does not require removing the automatic transmission from the machine and disassembling it.

The main problems of electronic devices in vehicles:

1. Unstable functioning of automatic transmission sensors. It happens that the machine is controlled in automatic mode, and then exits this mode on its own. And it can be in this state even after the engine is stopped.
2. Finding the gearbox in emergency mode for a long time.
3. Short circuit of electrical wires. In this case, the machine does not respond to gear shifting. At the moment of impact on the selector - a complete lack of reaction. The automatic transmission is in emergency mode.
4. Failure of the electromagnetic solenoids of the valve body of the automatic gearbox, as well as the electric pressure regulator of the hydraulic system. In this state, the vehicle responds inadequately to gear shifting, while bumps and mechanical sounds in the form of grinding are heard. An unauthorized transition to emergency control mode and spontaneous exit from it occurs.

To diagnose and eliminate the listed automatic transmission faults, it is not required to dismantle and disassemble the automatic transmission. A special scanner is used here, with the help of which such indicators are measured: electrical resistance, inductance, etc.

Why automatic transmission speeds do not switch - the main reasons

Experienced auto mechanics and drivers have noticed that most automatic transmission faults lead to failures in the main function of the automatic transmission - gear shifting. Thanks to high qualifications and experience gained, many specialists of service companies determine the most likely causes of automatic transmission malfunctions by indirect signs:

• reduced level of ATF lubricant;
• accelerated wear and combustion of clutches;
• violation of the integrity of the brake band (breakage);
• clogging of the gearshift valve;
• failure of the elements of the automatic transmission torque converter.

With a decrease in the volume of transmission oil in the gearbox lubrication system, slippage begins at the moment the vehicle starts moving. There are also jolts and kicks of the box when shifting to another gear. With oil starvation, the vehicle may come to a complete stop. If at the same time there are malfunctions of the automatic transmission torque converter, the main working units and transmission mechanisms are destroyed.

Tip: When the first signs of automatic transmission malfunctions appear, it is recommended to add fresh oil to the automatic transmission, replace the oil filter. If serious complications are noticed in the operation of the box, you need to contact qualified craftsmen for advice and help.

What is the danger of friction clutch wear? the dust generated during the abrasion of the friction linings covers the parts of the automatic transmission oil filter, the mesh becomes clogged with wear products, the oil pressure in the hydraulic system of the automatic transmission drops sharply. With this defect, the car gets out of control and begins to behave unpredictably:

• he can move forward, but at the same time he does not have a reverse mode;
• or vice versa, there is a reverse gear, but there is no forward movement;
• slippage when the transmission oil is heated.

If the tape breaks in the automatic transmission brake system, the safety of the vehicle is seriously violated. To identify this defect, the driver is recommended to carry out a regular visual inspection of the vehicle's braking device.

To restore the operation of the automatic transmission shift valve, it is necessary from time to time to remove and clean the device from dirt accumulations. After careful maintenance, the valve is reinstalled.

The design of the automatic transmission torque converter does not provide for disassembly of the unit. The unit is a non-separable mechanism. Therefore, if any working component of the torque converter fails, it will be necessary to completely dismantle the mechanism and install a new copy. Correct operation of the vehicle is a guarantee of long-term operation of the GTF. The mechanism is designed for uninterrupted operation for 200,000 km of run (not less).

Interesting: If you have certain technical skills, some craftsmen restore the performance of automatic transmission torque converters. To do this, it is carefully cut, providing access to problem parts and assemblies. After the repair, the unit body is welded using welding equipment. At the same time, the mandatory requirements for ensuring the tightness of the welded seam are fulfilled.

Tips from experienced car owners on the correct operation of the automatic transmission

In order not to bring a car equipped with an automatic transmission to a premature overhaul, certain rules must be followed during its operation:

1. Carry out timely car maintenance.
2. Change ATF transmission oil and filter elements, in accordance with the recommended periods specified in the accompanying documentation for the car.
3. Carry out a visual inspection of the automatic transmission in order to identify, repair and replace components that have received premature wear or destruction.

Subject to the listed requirements, the service life of the automatic transmission box will be guaranteed to be extended.

It is known from the practical experience of specialists that, in contrast to, high-quality at home is almost impossible. It is best to repair automatic transmission faults in service centers equipped with modern specialized equipment with a large stock of original spare parts.

Automatic transmissions are very complex mechanisms with a huge number of parts. It is possible to determine exactly what possible problems with the automatic transmission arose in this particular case, only with a complete disassembly of the automatic transmission.

Sectional automatic transmission

First, you need to remove the error codes of the self-diagnosis system and decipher. In addition, you can ring the chains, measure the pressure, do a driving test. However, such diagnostics and procedures rarely give an accurate picture - the box needs to be dismantled and disassembled.

Repairing automatic transmissions indiscriminately is like treating a patient based on his external symptoms and the information that he himself brought to the doctor. That is, treatment without any tests. And in medicine, there can be several hundred diagnoses for each symptom.

With the strange behavior of the automatic transmission, a chaotically appearing error, you can check the loops, change the oil and precisely set its recommended level. This can help on modern super-precise BMW automatic transmissions, for example, or tired automatic transmissions with over 200,000 kilometers of mileage.

Also, without dismantling, you can inspect the valve body, its sensors and loops, which could also be a source of malfunction of the automatic transmission. However, for cars with over 120,000 mileage or for those that do not come out of emergency mode, things are unlikely to end up with such simple procedures.

It is highly discouraged to identify parts that need to be replaced "by ear" or in another magical way without opening the box.

The most common reasons for the early breakdown of the machine are violations of the rules for its operation. Actions that exactly lead to a malfunction of the automatic transmission:

1. Aggressive driving and slipping;
2. Negligence towards the condition of the transmission fluid, filter, failure to perform maintenance on time;
3. Untimely change of consumables: oil seals, seals, solenoids and their wiring.

All this leads to approximately one picture - oil starvation inside the box and increased wear and tear of its parts.

After 120,000-200,000 kilometers in any box, significant wear of parts is observed and overhaul and diagnostics are always necessary, since the first automatic transmission malfunctions begin. If you do not do it, the automatic transmission is able to drive for some more time, but it will still get up at one "perfect" moment.

It is quite difficult to repair an automatic transmission with your own hands, but it is quite possible if you have the necessary knowledge, skills, tools and premises. For the most part, automatic transmissions are supplied with comprehensive drawings and manuals for repair and diagnostics, which can be found on the Internet.

Major transmission malfunctions

Leaking oil seals, rings and bushings. Absolutely normal situation after 200,000. Automatic transmission malfunctions arise due to simple wear and obsolescence of parts. Sealing elements tan, crack, lose elasticity and begin to let oil through. This little nuisance signals the car owner that the torque converter clutch has worn down to the adhesive layer and now does not fulfill its function. It begins to slow down more, slip and overheat terribly, transferring the temperature that arose from the friction force directly into the lubricant. Dirty oil clogs the pump, destroys its oil seal and bushing, which leads to oil starvation and failure. In addition, the oil with the remains of the clutch contaminates the valve body. Its channels are clogged and destroyed by abrasive treatment, it starts to work incorrectly and gives abnormal pressure to the box. The wear of the torque converter is preceded by an increase in fuel consumption, loss of vehicle dynamics, leaks on the box and extraneous sounds during the operation of the transmission.

Oil on the body is a sign of leaking oil seals

Previously, the sealing elements were made of cast iron, and they survived almost all the mechanisms of the box. Now they are made from rubber and Teflon. Dirty oil can, over time, make holes in them, from which oil begins to ooze. The pump tries to rectify the situation and drives more and more transmission fluid there. Therefore, all sealing elements are changed at every opportunity and are produced in sets.

Lack of oil. From an insufficient amount or pressure of oil, the gearbox mechanisms no longer receive a sufficient amount of lubrication. The clutches and steel discs begin to slip. Loss of dynamics is a clear sign of the necessary repair of the box and it is very foolish to ignore it. Overhaul and diagnostics during this period will be cheaper, and after them the automatic transmission will live for a long time.

If the clutches have completely burned out, then the oil, most likely, has become almost black and has definitely acquired a distinct burning smell. All clutches in the automatic transmission, even those not worn out, are soaked in burnt oil. Actually, it is too late to repair, only to restore or order.

Hydroblock. Previously, valve bodies were practically eternal. They were made in cast iron, there was no fine tuning, calculations and channels calculated to a fraction of a millimeter. The modern valve body is made of soft aluminum with a mass of thin channels, which are very easily clogged with debris from oil and are bored with it, like a file. Now they need to be periodically cleaned, usually this procedure is performed during a major overhaul. Their resource is one of the smallest among automatic transmission parts, and breakdowns have become commonplace.

Debris particles either clog the spools with solenoids, which leads to their sticking, or bore their channels, which leads to abnormal operation of delicate electronics. The result is always the same - in case of abnormal operation of at least one valve in one of the clutches, either an excess of pressure or a lack of it is observed, the clutches begin to slip and die, then pulling the entire box with them, which now runs on burnt oil.

The solenoid plungers, clogged with oil, stick, and this leads to their switching every other time, jerks and jerks are observed.

But even this was not enough for the engineers. They began to wiring the electrical part of the automatic transmission in the form of loops as thick as a human hair, and the electronic control unit from the car was transferred to the hydraulic plate itself. To make it overheat better, obviously.

With the help of such a cunning solution, the electronics of the automatic transmission also became a very unreliable place. A small detached wire can give very frightening breakdown symptoms in the form of jerks and kicks in the gearbox switching.

Signs of a malfunction of the automatic transmission in the valve body

• The box only works well for cold / hot. Solenoid dirty.
• The car cannot move, the reverse works. It's about the valve.
• Transmissions are not activated. The solenoid has broken.
• Only reverse and first gear work. Valve stuck.
• Slipping as you move up the hill. Valve body solenoid or channels.
• Shocks and jerks during transmission operation. Such breakdowns can cause contamination of the valve body and breakage of the wiring.
• The car stalls when changing to the next gear, if you do not accelerate. The valve is stuck, breakdowns have occurred in the mechanical part of the automatic transmission.

"Iron". Planetary gear, hubs and calipers. As the box and the sealing elements wear out, vibrations increase. Multiply this by oil starvation and you get completely imperfect conditions for contacting metal parts. They begin to wear out, crumble, burst. Breakdowns in the "iron" part of the machine are typical for older machines, they rarely occur on new ones.

Probable iron breakdowns

• Rumble, vibration, increasing with acceleration. Fatigue of the bearing, bushing or planetary gear;
• The car does not go, there is a reverse speed. Worn bushing, friction disc, clutch, breakage of the piston cuff.
• Reverse and 3-4 gears have disappeared. A cut spline connection is added to the points described above.
• There is only a reverse. Fatigue of the brake band, clutch packs, breakage of the piston or rod cuff, the entire brake pack is broken.
• The machine cannot move and does not respond to selector lever changes. The reverse speed does not turn on, the front one turns on when the gas pedal is pressed. Death of the torque converter, oil pump, clutches, brake band, pistons, all o-rings. It is worth checking the dipstick, maybe there is simply no lubricant in the transmission.
• Shocks when changing the position of the selector, but the car skids. Not enough oil, clogged filter, torque converter died.
• The car stalls while storming uphills. Lack of lubrication, wear of clutches, pistons, oil pump.
• Slipping when starting from a standstill. Worn torque converter, clutches, clutch cuffs.
• The car drives in neutral, as if at speed. Incorrect adjustment of the gear selector, a malfunction of its sensor, the piston is seized, the friction discs are stuck together.

• Gear changes only take place at high speeds. Incorrect adjustment of the cable, the valve of the centrifugal regulator is stuck, the filter is clogged, the throttle valve is stuck.
• The kickdown is gone. The sensor or its wiring died, the valve stuck, the cable was incorrectly adjusted.
• Shocks and jerks when changing gears. Worn clutches or brake band.
• The machine moves and starts moving with great difficulty. The torque converter died.
• Metal sounds, hum in the box. Worn gears, bearings, differential, satellites.
• After warming up the automatic transmission, the car does not run. Friction clutch wear.
• The car stalls when shifting gears, if you do not accelerate. Torque converter.
• Metal particles in the pallet. Worn planetary gear, bearings, planet gears, bushings, differential.
• Plastic particles in the pallet. A bushing, washer, washer or other element is broken.
• Balls in the pallet. The bearing is crumbling.

Deciphering the codes of the automatic transmission self-diagnosis system

To determine the breakdowns of the machine, there is its own electronic self-diagnosis system, which is combined with the generally accepted OBD-II system.

Defective control unit

Control unit errors

The electrical part of the control system is faulty

P0703, P0719, 724

Defective torque sensor when reducing speed

Incorrect readings of the clutch sensor

Incorrect readings of the selector position sensor

Incorrect adjustment of the selector sensor

Invalid selector sensor readings

Incorrect readings of the coolant temperature sensor

Incorrect turbine sensor readings

Incorrect readings of the shaft speed sensor

Incorrect readings of the engine speed sensor

Incorrect adjustment of the automatic transmission

Incorrect adjustment of the first gear

Incorrect adjustment of the second gear

Incorrect adjustment of the third gear

Incorrect adjustment of the fourth gear

Incorrect fifth gear adjustment

Incorrect reverse adjustment

Defective clutch

Faulty pressure regulator

Defective first shift solenoid

Defective second shift solenoid

Defective third shift solenoid

Faulty fourth shift solenoid

Faulty fifth shift solenoid

Defective switch

Defective first and second switches

Defective second and third switches

Defective third and fourth switches

Faulty fifth and fourth switches

Wrong readings of the solenoid sensor

Defective normal mode

Broken reverse

Defective switching solenoid 1-4

Switching backlight 1–4 defective

Reverse is faulty

Brake sensor defective

Parking and neutral mode is not detected

Temperature sensor not tested

Slip sensor error

All wheel drive error

Defective torque control unit

Torque converter clutch sensor error

Electronic pressure regulator error

Shift solenoid errors

Defective control unit

Faulty all-wheel drive switch

Transmission temperature exceeded

CCS solenoids defective

Automatic transmission - an automatic gearbox - is one of the main components of any car. Failure of this element is fraught with serious problems, and it is not recommended to postpone the resolution of the problem. Naturally, any motorist should have basic knowledge of automatic transmission breakdowns, including their causes and ways to eliminate this unpleasant situation. Note that we did not analyze the problems of specific brands, since all automatic transmissions are similar in their structure, signs and causes of malfunctions.

Signs of automatic transmission malfunction

The symptoms of an automatic transmission malfunction can be completely different (specific examples are described in the table of malfunctions below). The operation of any car is invariably associated with serious loads on the transmission, as a result of which the automatic transmission may fail. Although the vast majority of well-known brands try to maximize the life of each of the constituent elements, the gearbox is still relatively vulnerable. The most characteristic "symptom" of a malfunction is the occurrence of jolts and jerks while driving.

It should only be noted right away that the occurrence of malfunctions obliges you to contact the specialists as soon as possible; "Lingering" can make it worse. Also, the occurrence of problems with the automatic transmission often becomes one of the root causes of an accident: driving a car with a failed (or failing) gearbox is a serious risk to life.

The vast majority of modern cars are equipped with special sensors and regulators that notify the driver about:

• low level of transmission fluid;
• the appearance of problems with changing modes;
• too high an automatic transmission temperature;
• low pressure of working lubricant.

The main causes of malfunctions

• Leakage. One of the most common problems is oil leakage. This is most often due to the wear of the seals made of rubber. The motorist is also capable of detecting a transmission fluid leak on his own - it is enough to visually inspect the vehicle on a pit or overpass. Noticing smudges, do not hesitate with repairs, since the problem can be solved in the shortest possible time: most often enough. In general, every motorist is recommended to carry out a visual inspection with a certain frequency: often this allows you to identify the problem in advance and thus reduce repair costs.
• Lever curtain. If your vehicle is equipped with an old-style gearbox where the selector and transmission are “traditionally” (mechanically) articulated, the first suspicion should fall on the linkage. Failure of the selector wings in the overwhelming majority of situations makes it impossible to switch driving modes. The "advantage" of such a problem is the simplicity of its solution: to fix the problems, it will be enough to change the lever and the wings, the cost of which is relatively low. A characteristic "symptom" that is worth paying attention to is a difficult change in the position of the gear lever. If the selector does not move at all, it will be impossible to set the speed.
• Control block. In some situations, failures in the automatic transmission robot are caused by a malfunction of the control unit. For example, the latter sometimes "makes mistakes" in the choice of revolutions when switching driving modes; in some cases, blocking of all work may even occur. This is a rather "serious" malfunction, in which repair does not mean repairing (usually impossible), but replacing the damaged element with a new one. The adjacent trains are also changed.
• Hydraulic block. Failure of a hydraulic block is one of the most common problems. It occurs for a variety of reasons; an example is the illiterate operation of the transmission. If you do not warm up the car before leaving at sufficiently low temperatures (especially important in the realities of the harsh Russian winters), but immediately start moving, the service life of the hydraulic unit is significantly reduced. The symptomatology here is quite striking: these are shocks, shocks, vibration; in some cases, the car may even "refuse" to start. In the case of modern vehicles equipped with an on-board computer, diagnostics are not required: the system will automatically notify you of the problem.
• Hydraulic transformer. Typical signs of a breakdown of a transformer: the appearance of a strange rustle, vibrations, knocks; dynamics will deteriorate, and when changing the working fluid, you can see a small amount of steel shavings in the pallet.

Prevention of malfunctions

The best way to solve a problem is to prevent it. Having briefly talked about common problems (a more detailed analysis will be given below), we will highlight certain preventive measures - rules, the observance of which does not guarantee the absence of automatic transmission malfunctions, but seriously reduces their likelihood:

• Working fluid. Regular replacement of the lubricant is the key to the absence of problems with the automatic transmission. Ignoring this rule will significantly reduce the transmission life.
• Warming up. It has already been said above that breakdowns often occur in the winter. Be sure to warm up the car: this will minimize the likelihood of malfunctions associated with the lubrication of the moving elements of the system.
• Riding. The automatic transmission wears out much faster with an "aggressive" driving style. It is not worth it to "add speed" in vain, even when the situation on the road is conducive to such a thing. Regular operation of the engine at high speeds leads to grinding of elements and combustion of the transmission clutches.

Basic methods for diagnosing automatic transmission faults

• Sounds. In the event of a breakdown of the automatic transmission, it is often possible to diagnose the problem "by ear". Malfunctions often reveal themselves in the form of squeaks and strange grinding, often accompanied by vibration. If the unit is out of order, an experienced motorist realizes this almost instantly. However, do not rush to sound the alarm: sometimes it is enough to clear the regulator from oil or change the working fluid (for example, add oil to the system) to eliminate malfunctions.
• Manipulation. Sometimes, to diagnose the problem, you will need to conduct a close inspection of the vehicle's electrical wiring system. If you know the construction of a car, it shouldn't take more than ten minutes. If the automatic transmission malfunction is serious, it may show up after removing the pallet. It is also recommended to measure system pressure and clear fault codes.
• Bulkhead. Of course, dismantling the automatic transmission and the subsequent bulkhead of the device remains the best diagnostic method. If the transmission is in emergency mode, it is sufficient to disassemble the transmission. Most often, the need for dismantling and sorting appears in the case of cars that have traveled long enough distances - more than one hundred thousand kilometers. The consequence may be wear and tear, and hence the need to change the clutches.

Detailed analysis methods

If your vehicle has an automatic transmission, which is controlled by an electronic unit, you can carry out computer diagnostics. In this case, you will have to use a cable to connect to the OBD II connector and software that will make it possible to read data from the automatic transmission. The purpose of such manipulations is to search for error codes that are recorded in the memory of the engine ECU. It is not difficult to decipher the received data. If you could not find the error codes on the Internet for your car model, look for them by the automatic transmission model.

An important point must be taken into account: computer diagnostics cannot identify problems associated with poor contacts or oxidation in the electrical wiring connectors. Therefore, an additional detailed check of the wiring and connectors is required. The appearance of oxidation, deformation of the wires - all this can be the cause of malfunctions in the operation of the gearbox. The study of electrical wiring involves the following steps:

• Visual analysis (you need to look for "oxides", check the integrity and connections).
• Using a multimeter with which you can check the wires. It is also recommended to clarify the value and parameter of the voltage at the contacts of the control module.
• Uses a halogen lamp and a safety switch. By performing a no-load wiring test, you can determine if there is an open circuit. However, keep in mind that the quality of the contact cannot be checked in this way.

If you do not have the necessary equipment and sufficient experience, you can.

Trouble table

Let's analyze common problems in the form of a table of correspondence of signs to causes (we have omitted some of the situations that motorists have to face extremely rarely):

Symptoms of a problem	Causes
The car does not move forward, starts to slip.	Friction discs, piston clutch cuffs, clutch rings could be worn out; there may be a problem with the valve of the hydraulic block
Reverse, third and fourth gears are not included.	As a result of wear, one of the following system components has failed: friction disc, piston cups, clutch ring oil seal.
When you try to change gear, you feel a serious jolt, but there is no movement to either side.	A hydraulic transformer has failed, or there is simply no oil lubrication in the system (the oil filter could have failed).
The vehicle only moves at third speed.	There are many options here: friction discs, clutches, piston cuffs, clutch rings could have worn out; sometimes the valve of the hydraulic block also sticks.
Impossible to drive when shifting into reverse gear.	Most often, the situation is caused by wear of the brake band (or its piston cuff) or deformation of the piston rod.
Gear shifting "to cold" (without warming up) is accompanied by a jolt.	Most likely, there are problems with the solenoids or the hydraulic block.
The machine does not move backward or forward, and when shifting from "P" to "N" there is a jolt.	Among the possible root causes: a hydraulic transformer malfunction, wear of the pack piston cuffs, a lack of working fluid, a malfunction of the drive gear of the oil pump, problems with the solenoid, wear of the oil seals of the clutch ring, contamination of the filter mesh.
The machine hums and vibrates (often appears at high speeds)	Bearings worn out.
Only reverse, first and second gears will be engaged.	Perhaps the problem is a dirty valve in the hydraulic block or in the solenoid.
The car moves only when the selector is in "N"	There are problems with adjusting the cable or lever, the piston of one of the clutches is seized, or the friction discs are welded with other elements of the system.
At high speeds, the gears shift "by themselves".	It is possible that the throttle valve cable is incorrectly adjusted (it often fails altogether) or there is a blockage in the filtration system.