Scheme of operation of automatic transmission - Automatic gearbox. Controlling an automatic transmission in a car and operating an automatic transmission

Automatic transmissions are becoming increasingly popular in the market. If someone at one time thought that understanding the mechanics was not easy, then it’s time to plunge into the wonderful world of automatic transmission operating rules! Before trying to pull the lever, it is recommended that you read the instruction manual , which was created for a specific box model for a specific machine. This is useful not only because different automatic transmissions may have a different number of available modes, but also because the symbols of the modes in different models do not always coincide.

Today it is customary to distinguish three types of automatic transmissions: “robotic mechanics”, “stepless variator” and “classic”. All of them (depending on the specific model and manufacturer) differ in the number of modes, as well as in the stroke of the lever (straight, zigzag). However, the basic functions of all automatic transmissions are completely the same.

Despite the apparent complexity, the automatic transmission is very easy to use. This is precisely the reason for the ever-growing popularity of such boxes.

What is a classic automatic transmission?

There are several types of automatic transmission, which were a natural consequence of its evolution:

Classic, with torque converter;
robotic, with one or two clutches;
Continuously variable transmission (CVT).

Cross-section of a classic automatic transmission
A classic automatic transmission is a type of transmission that, while driving, sets the desired gear ratio depending on the speed, driving mode and other conditions. Unlike other types of automatic transmissions, a classic automatic transmission must have a torque converter, with the help of which the torque from the engine crankshaft is transmitted further to the input shaft of the gearbox. The torque converter performs the same role as the clutch in a manual transmission, increasing torque, but at the same time working without driver intervention.

What do the position symbols mean?

The range selection lever (RVD) has several positions, which are designated by letters and numbers. The number of these positions is different for different car models, but on all cars the RVD necessarily has positions designated by the letters “P”, “R” and “N”.

Position "P"

Selected when parking the car for a long time. In this position, all controls in the automatic transmission are turned off, and its output shaft is locked, so movement is impossible. In this mode, engine starting is allowed.

Position "R"

Reverse. Moving the lever to the “R” position while driving can lead to gearbox failure. In this position of the RVD, starting the engine is impossible.

Position "N"

All controls in the transmission are turned off or only one is turned on.
The output shaft locking mechanism is disabled, i.e. the car can move freely. In this mode, engine starting is allowed. For vehicles equipped with four-speed transmissions, the range RVD has four forward travel positions: “D”, “3”, “2” and “1” (“L”). If the lever is installed in one of these positions, starting the engine is impossible.

Range "D"

Basic mode.
It provides automatic shifting from first to fourth gear. Under normal driving conditions this is what is used. “D 3” - movement is allowed at the first three speeds. Recommended for use when driving in stop-and-go traffic. “D 2” - movement only in first and second gears. Used on mountain roads. Shifting to third and fourth gear is prohibited.

“D 1” - driving only in first gear is allowed. Allows maximum implementation of engine braking mode. For example, when driving on steep slopes.

On some cars, permission to use the fourth, overdrive gear is carried out using a special “OD” button. If it is recessed and the lever is set to position “D”, then upshifting is allowed. Otherwise, engaging the fourth overdrive gear is prohibited. The system state in this case is reflected using the “O/D OFF” indicator.

Types of automatic transmissions - how they differ

Overdrive means overdrive. Identified as "OD", "D" or D in a circle. Overdrive is used for economical driving on the highway.

What is an automatic transmission

An automatic is a transmission in which gears are changed without driver intervention. To control the gearbox, there are brake and gas (accelerator) pedals in the cabin, as well as a mode selector.

There are different types of automatic transmission:

“classic” gearbox with planetary mechanism;
continuously variable CVT;
robot.

The first two types use a torque converter as a clutch, while the robot uses discs.

The automatic transmission transmits torque from the engine to the wheels. In addition to direct transmission, the automatic transmission reduces or increases gear ratios, which allows you to start and move the car at different speeds. So, to move the car from a standstill, more power is needed, so the first stage has a gear ratio higher than 2. To maintain high speed, a “sprinter” is needed - the highest stage with a number less than 1.

The number of stages determines how much torque the automatic transmission can handle and how invisible the shifts will be. Until the 2000s, automatic machines had 3-4 stages. The most popular now are 5-, 6-. 8-speed. There are also 9-speeds, for example, ZF9HP28/48, and 10-speeds, GM 10L90.

Mode "D" or "Drive"

The fourth main mode on an automatic transmission is the “Drive” mode, the main driving mode intended for driving the car forward. Most often indicated by the “D” icon and is located immediately after the “Neutral” mode. It turns on before you start driving and turns off by moving the selector to the “Parking” mode after it ends.

It is worth saying that on many cars the “Drive” mode has special protection against spontaneous activation, so it can only be turned on after pressing the brake pedal and/or pressing a special button on the automatic transmission selector.

Advantages and disadvantages of automatic transmission

The mere fact that the classic automatic transmission is still installed on new car models speaks of its good reputation. However, there are many opponents who prefer the good old “mechanics” and criticize the short service life of the automatic transmission and expensive repairs. The truth, as always, is somewhere in the middle.

Automatic transmission has many advantages:

Convenience. There is no clutch basket, no additional pedal;
The torque converter does an excellent job of clutch function, including damping sudden crankshaft vibrations (in a manual transmission, this task is performed by a dual-mass flywheel). Such a system spares the engine, the gearbox itself, and the chassis;
The system itself selects the optimal gear ratio, and there is no need to worry about how to drive and in what gear;
Reliability of the mechanism. Despite its complexity, the automatic transmission is quite reliable, if, of course, it is used correctly.

There are also disadvantages because of which many car enthusiasts prefer not to mess with automatic transmissions:

The need for regular maintenance. Replacing fluid and filters must be done strictly at certain intervals, and the level and condition of the fluid in the box must be monitored no less carefully than the oil level in the engine;
Repair cost. Due to the rather complex design, as well as significant weight, it is almost impossible to repair the box yourself. Special equipment is required, including for diagnostics;
Poor foolproofing. It is much easier to damage an automatic transmission than a manual one, especially for those who like to suddenly pull away from a traffic light;
Higher fuel consumption than with a manual;
If there is a serious malfunction of a car with an automatic transmission, you will have to call a tow truck: this transmission does not like to be moved “on a tie” - again additional costs.

It should be noted that the persistent opinion about the unreliability of “automatic machines” has a certain basis: some of their modifications actually turned out to be unsuccessful. However, there are also ultra-reliable models from reliable manufacturers that can last hundreds of thousands of kilometers.

Advantages of contract automatic transmissions

Buying a new automatic transmission, especially an original one, will be expensive, so motorists are usually looking for an alternative, which can be:

used automatic transmission purchased on the domestic secondary spare parts market;
a restored automatic transmission, that is, a unit with previously existing defects, removed from a used car and undergone a major overhaul;
contract automatic transmission from a foreign car dismantling site.

The best option in terms of price, quality and service life is a contract automatic transmission. It is superior in quality to cheap analogues from third-party manufacturers and used parts removed from cars that were used in Russia, and is more affordable than original new and even restored boxes. Compared to analogues, contract spare parts benefit because they are original. What sets them apart from used spare parts from the domestic market is their condition:

donor cars were operated only abroad, using high-quality oil;
Cars with low mileage usually end up in scrapyards: cars are replaced abroad much more often than in Russia.

Contract automatic transmissions are often called a “pig in a poke,” although this can most likely be attributed to reconditioned units:

there is no guarantee that new and original parts were used during restoration;
restoration requires highly qualified craftsmen;
during restoration, only some of the parts are replaced, but many others remain, the service life of which is already running out, so that another repair may soon be needed;
Many restored automatic transmissions are repaired in the second round.

Contract automatic transmissions are usually removed from cars long before they need major repairs. But this unit requires maintenance before installation on the car. All filters and rubber products in the automatic transmission should be changed and the oil should be changed.

Automatic transmission operating principle - service life

The load on the engine and the speed of the car affect the time required to change gears. The control system determines the hydraulic influences required for operation. Elements of the planetary mechanism (brakes, clutches) change the gear ratio, establishing the optimal engine mode under given conditions.

We discussed the operating principle and design of an automatic transmission above. The efficiency of the unit depends on the level of the working solution, which must be controlled. ATF oil operates at 80 degrees Celsius. In winter, the car must be warmed up so as not to damage the plastic of the unit. In hot weather, on the contrary, cool with an oil radiator (air) or refrigerant.

How does a car's automatic transmission work? In practice everything is very simple. The main selector designations are usually called in English (the explanation is given in parentheses):

Drive (to move forward);
Reverse (reverse);
Parking (blocks the transmission output shaft for parking);
Neutral (“neutral”);
Manual (to switch to manual control).

These are the basic modes. If you are faced with additional options, review the information from the manufacturer.

What are the main advantages and disadvantages

A car with an automatic transmission is equipped with a passive safety system that does not allow the engine to be started in positions other than “P” and “N”. It also prevents spontaneous movement of the car when parked on an uneven surface, because You can remove the key from the ignition switch only in the RVD position “P”. The disadvantages include lower efficiency than that of manual transmissions, which increases fuel consumption.
But modern automatic transmissions in some driving modes make it possible to achieve higher efficiency compared to manual transmissions by maintaining optimal engine speeds and “intelligent” control of torque converter lock-up. Another drawback is the worse dynamic acceleration of the car. The difference is not so great and is insignificant for the majority of drivers. Also, a car with an automatic transmission cannot be started except with the help of the starter.

How to use an automatic transmission correctly

In order to prevent problems in the operation of automatic transmissions, you need to learn how to operate them correctly and take into account the rules of use and driving.

How to start moving:

The brake pedal is sunk to the floor. The gear lever switches from the parking or neutral position to D - drive.
The car is released from the parking brake.
The brake pedal is smoothly released and as a result the car begins to move smoothly forward.
To increase the speed of movement, the driver presses the gas pedal. The harder he presses, the more the speed increases. To reset it, you just need to release the gas pedal. The automatic transmission will automatically begin to reduce the speed of movement.
If you need to quickly slow down or stop, the driver presses the brake pedal. If you need to move further, just press the gas.
Please note that during such operation, the automatic transmission must always operate in position D. This mode can be turned off for a long stop.

Transmission control features:

Automatic units should not be used in cold conditions under high loads. If it’s summer outside, after parking the car you still need to warm it up by driving several kilometers at a reduced speed and without performing accelerations or other maneuvers. Keep in mind that the transmission takes longer to warm up than the car's engine. In order for the lubricant in the automatic transmission system to heat up faster, it is recommended to turn on all positions on the lever. Or, before driving, turn on the winter mode, if it is supported by your car’s automatic transmission.
Stick to driving on smooth roads. Most modern cars have a negative attitude towards driving on uneven surfaces, unless we are talking about a car specifically designed for such roads.
You need to press the brakes and start moving smoothly after stopping. Such operating conditions lead to an increase in the distance between the automatic transmission clutches. As a result, there will be jerking when you change gears. Operating the car will become less comfortable. With a sharp start, the seals begin to rub against the drum, which leads to their rapid wear. Grooves and retaining rings wear out, resulting in wear debris in the form of metal shavings appearing in the system. As a result, when switching the selector, a crackling and crunching sound will appear. Under high loads, bearing elements quickly break.

Techniques for driving a car with an automatic transmission

Having understood how gears are changed on an automatic transmission, and also having examined the main operating modes of an automatic transmission, you can move on to how to drive an automatic transmission.

Let's start with the basics. It is important to understand that the automatic transmission is “afraid” of constant sharp acceleration from a standstill, as well as wheel slipping in mud, snow or ice. Such conditions lead to the automatic transmission overheating.

For example, if the car is slipping, and no mode allows you to leave, it is better to seek outside help and simply push the car or tow it in N mode.

Let's get back to driving an automatic and how to drive a car with an automatic transmission. Driving a car with an automatic transmission comes down to the following:

You need to start using the automatic transmission with the brake pedal pressed.
by pressing the brake, to start moving, move the selector from P or N to the desired mode (R, D, 3, 2, L);
If the parking brake was previously applied, the handbrake must be “lowered”.
by removing the car from the handbrake and releasing the brake pedal, the car will slowly and smoothly begin to move (in some cases, for example, if the car is standing on an incline, there will be no rollback in mode D, but there will be no obvious forward movement);
To accelerate, you need to press the gas pedal (accelerator). In D mode, the automatic transmission will automatically upshift when accelerating and downshift when decelerating. To reduce speed slightly without using the brakes, simply release the gas completely.
To achieve effective deceleration/full stop, you need to apply the brake. To further accelerate, just release the brake again and press the gas.
There is no need to switch the selector from mode D to mode P or N during short stops (these modes are activated only during long periods of inactivity with the internal combustion engine running for 10-15 minutes or more).
Taking into account the presence of different operating modes of the automatic transmission, the driver should select the one that is best suited for specific operating conditions.

Please note that it is prohibited to move the selector to positions P and R until the car has come to a complete stop or while moving. Ignoring this statement will lead to serious damage to the automatic transmission.

It is also strongly recommended not to turn on N while driving, as this may cause a skid on a snowy road or on ice. It is not prohibited to switch the box to other modes while driving.

It should also be taken into account that if there is a need for the car to remain idle for a long time with the engine running (traffic jam, etc.), while high outside air temperatures are noted, then the selector must be switched from mode D to mode N to avoid overheating of the automatic transmission.

How did I come to this question?

I can’t say that I haven’t tried to find out information about these automatic transmission modes from my friends. However, none of them was able to answer this seemingly simple question. And I would have remained in the dark if one day my friend and I had not decided to take a trip outside the city.

Each of us drove our own car. And since the comrade knew the road better, he moved first. Ahead of us was a section with constant ups and downs, on which I constantly slowed down. At first glance, my friend was driving the same way, but I noticed that his brake lights did not turn on, despite the fact that the car was clearly slowing down.

Fearing a breakdown, I called him and asked him to stop. At a nearby parking lot I asked him a question about the brake lights. And imagine my surprise when he replied that he did not slow down at all on the slopes.

Description of the main operating modes of the automatic transmission

For all cars equipped with an automatic transmission, the mandatory functions are automatic transmission modes, which are indicated on the control panel by the Latin letters P, R, D, N. To switch to one of the modes, the driver operates the range selection lever - selector. Externally, this mechanism is very similar to the usual gear shift lever installed on a manual transmission. The main difference is the way the automatic transmission is controlled. The driver does not need to be distracted from the situation on the road in order to switch to another operating mode.

P – parking mode (parking).
R – reverse (reverse).
D – forward movement (drive).
N – neutral gear.

Drivers select parking mode P if the car stops for a long time, for long-term parking. In this case, all controls are disabled and the output shaft and wheels are locked. Even when the engine starts, the car cannot move.

When you try to move the lever to the reverse position R while the car is moving, the working elements of the automatic transmission break and fail. If the transmission is not equipped with a special locking system, it is prohibited to engage the reverse mode until the car has completely stopped. It is used when it is necessary to return it. If the gearbox lever is in position R, it is also prohibited to start the internal combustion engine.

The most popular is mode D. Thanks to the “Drive” mode, drivers are provided with conditions for the most comfortable driving of a car with an automatic transmission. When you press the gas pedal hard to the floor, the automatic transmission independently selects the most suitable speed. If you need to brake or change driving conditions, the engine automatically applies braking.

Starting a car with automatic transmission

Before you start driving an automatic, you need to learn how to start the car with the key:

Before starting the engine, check that the selector lever is in the “P” or “N” position. Electronics blocks the engine from turning on in other modes for safety reasons, so that the car does not roll spontaneously.
The entire process of driving a car with automatic transmission occurs with one foot. Place your left foot on the platform, your right foot on the brake pedal. This is also necessary for unlocking in some car models.
Insert and turn the ignition key. The lights on the panel will light up. Wait a few seconds for the pump to turn on and supply oil to the engine.
Start the engine starter.

How to start automatically

Before driving, warm up the engine so that its parts and working fluids reach operating temperatures. For the same reason, automatic transmissions are heated: at temperatures below 75 - 95℃, the fluid changes viscosity and is not able to fully lubricate, cool and protect the mechanisms. Therefore, driving “when cold” is harmful: the automatic transmission experiences high loads, and drivers complain about kicks, jolts, etc.

After the car has warmed up, you can start driving.

How to start with an automatic transmission:

Check that the selector is in position “P”: the car must be braked before starting.
Step on the brake.
Move the lever to “D” for forward or “R” for reverse.
Wait for a slight push - the automatic transmission needs a second to switch modes.
Release the brake pedal and the car starts moving.
To accelerate, gently press the gas pedal.

Drive away and accelerate smoothly using the automatic transmission. It takes time for the automatic transmission electronics to receive a signal about the driver’s action and send a command to the actuators. Driving aggressively is generally harmful: the gearbox experiences a lot of stress because the automatic transmission operates with insufficient lubrication.

How to brake

Braking can be divided into types:

normal;
emergency;
engine braking.

To slow down a car with an automatic transmission, press the brake with your foot off the gas pedal. Stop the car and move the lever to the “P” position. It is not recommended to use neutral mode, because... in this case, the wheels do not lock and the car may roll.

Please note how to properly drive a car with an automatic transmission in difficult situations:

Driving on a slippery road is dangerous - the wheels may slip when braking. For an automatic transmission this is not a problem. Long-term slipping of the drive wheels on snow, ice, and mud will cause more damage. To get out of a deep rut, shift into a lower gear and use the brake like a clutch, “rocking” the car. Every 2 minutes, let the automatic transmission cool down for 5 minutes.

To transmit large torque, the torque converter releases excess heat into the automatic transmission, and if the oil is old or the radiator is dirty, the box will overheat. We told you earlier why overheating is harmful.

On long descents, do not engage “N”: switching back to “D” at high speed will cause the automatic transmission to overheat.
Instructors recommend driving in manual mode on ups and downs in winter, as well as on mountain serpentines, so as not to skid.

Neutral mode N

After a manual transmission, it’s unusual to drive an automatic. We have to relearn. Here, for example, is neutral gear. Its role in an automatic transmission is purely technical: the “N” mode is designed to move a car with a running engine over short distances. In this case, the engine and automatic transmission are not connected to each other: the torque converter works, but the torque is not transmitted to the wheels, since the friction discs are constantly decompressed.

Neutral gear can also be engaged while parked, but in conjunction with the handbrake. This is familiar to beginners who are used to driving a manual car. But you don’t need to use this method at a traffic light. During the transition from “D” to “N”, the clutches disengage, the input and output shafts open. Then you move into “D” - the automatic transmission has to connect the mechanisms back. This is a complex process that leads to rapid wear of clutches and solenoids.

Reverse gear R

You can turn on reverse (mode R) only after stopping the car. You should press the gas and start driving after a short pause to avoid jerking. This is especially true for older cars.

The fact is that the reverse gear in some automatic transmissions is engaged with a noticeable delay, which increases with wear and when the oil temperature drops (for example, after a long period of inactivity in the cold). In the "R" position, you will be able to turn off the engine, but will not be able to remove the key.

Forward gear D

Drive mode is designed for forward movement and is activated after the car has stopped. While driving, "D" can only be activated from other forward driving modes, such as "2" or "3".

When you select mode “D” and release the brake pedal, the car starts moving, adding gas causes acceleration, and pressing the brake causes braking. Gears change automatically and without jerking if the automatic transmission is working properly.

When stopping briefly at a traffic light, you should not move the lever to the “N” or “P” mode. This leads to unnecessary wear of the parts responsible for changing the driving mode. Apply the brake and hold it until you can continue driving.

Description of winter mode “W”

The most popular among car enthusiasts is an additional program called “winter mode”.

Possible winter mode designations:

snowflake *;
"Snow"
"Winter";
"COLD";
letter "W".

When using this program, the car on a snowy track starts moving in second gear without slipping. Subsequent gear changes are made at lower engine speeds. This is designed to avoid sudden skidding and acceleration of the car. In summer, this program is not used, because in “Winter” the automatic transmission receives additional heating due to increased loads. At subzero ambient temperatures, the oil in the transmission cools quickly, so additional heating does not pose a threat to the transmission.

It is not advisable to use the “Snow” mode when driving on clean highways inside the city, where there is relatively good coverage. It is more in demand for driving on dirt country roads in winter conditions. The most dangerous use of the winter program is when the car is slipping. It is recommended to avoid places where the car’s wheels can get stuck (slippery areas under loose snow, deep puddles on dirt roads, etc.).

Mode "P" or "Parking"

The first main mode on the machine is the “Parking” mode (most often indicated by the “P” icon). The automatic transmission is switched to this mode when the car is parked. In this mode, a special lock is activated in the box, thanks to which the car cannot be moved (similar to the hand brake on a manual transmission).

It must be said that the “Parking” mode should be activated only after the car has come to a complete stop. Another common mistake many novice owners of cars with automatic transmission make is that they switch the selector to “Parking” mode while the car is still moving a little (coasting). In this case, there is a danger of damaging the blocker.

It is also worth noting that putting the car in “Parking” mode on a slope (forward or backward) has its own tricks. When the blocker is turned on, the car may have a “free movement” of about 5-10 cm (at the same time, it can roll downhill by these same 5-10 cm) until the blocker turns on. Subsequent removal from the “Parking” mode may be difficult and accompanied by uncharacteristic sounds, since the blocker will be under tension due to the car rolling back (by the same 5-10 cm). To protect the lock, before turning on the “Parking” mode and leaving the car on a hill, you need to secure the car with the hand parking brake.

Additional automatic transmission modes

Automatic transmissions of modern vehicles with a large number of operating ranges are equipped with several additional programs. To take advantage of additional features, drivers here use special switch buttons:

ECO mode (economical);
sporty S;
kickdown—maximum acceleration;
winter;
emergency.

When you turn on the economy program button, fuel is consumed in a minimal amount, thanks to the limitation of the speed range in each gear. When switching to a higher level, the power unit first operates at idle speed, gradually increasing it, but not reaching the maximum. This program ensures smooth, quiet running of the machine.

In S sport mode, the combustion engine operates at full power, which is utilized to the maximum by the gearbox. When the automatic transmission is switched to the next gear, the rotation of the output shaft is completely transmitted to the box, developing increasingly greater acceleration.

In maximum acceleration mode it is convenient to overtake on the road.

The emergency mode program is activated by the electronic control unit when a malfunction occurs in the ECU or automatic transmission. While in this mode, the car has the ability to independently drive in one gear to the nearest service center without switching.

Switching the lever on the fly

It is possible, but not in all positions.
It is strictly forbidden to move the lever to the “P” and “R” positions when moving forward. The lever can only be moved to both positions when the machine is completely stopped. Violation of this rule may result in transmission failure. It is not recommended to move the lever to the “N” position while driving, since the connection between the wheels and the engine is lost and sudden braking can cause a skid. And you can easily transfer to all other positions. In some cases it is recommended to do this on purpose. So moving the lever from position “3” to position “2” will increase the efficiency of engine braking. Should the lever be moved to "N" when stopping? It makes sense only during long stops in traffic jams in hot weather, to reduce heat generation and prevent overheating of the oil in the box. In other cases, this is not necessary.

How not to use automatic transmission

To prevent transmission failure, you need to study the automatic transmission manual in detail and take into account the following rules:

Towing a car with automatic transmission is not allowed. With classic transmissions, there is no rigid connection between the wheels of the car and the power unit, so in principle it will not be possible to start the engine by towing.
When driving at high speed, trying to shift the automatic transmission lever, watch the gears. If you are driving fast and accidentally switch to first or second gear, the car will suddenly brake and jerk. This is fraught with serious skidding and an accident.
While driving, switching the automatic transmission selector positions is not allowed. If the Drive mode is turned on, you cannot move the lever to the neutral or park position, this will lead to damage to the unit.
If the vehicle stops on a slope, be sure to apply the handbrake. Otherwise, the locking device may be damaged.
Engaging neutral gear when driving in traffic jams is only allowed in hot weather. At high temperatures, heated transmission lubricant will cool faster, but constant use of neutral speed is undesirable. Its activation is relevant when it is necessary to move the vehicle in emergency situations.
It is not recommended to experiment with different oils, especially with additives to the lubricant. If additives do not correspond to the technical features of the transmission, their use will lead to undesirable consequences. When replacing consumables, check the vehicle manufacturer's requirements for the use of oil.
Avoid wheel slip. This requirement is relevant for winter, when ice or snow prevails outside. You should especially not slip on asphalt. Modern cars are equipped with traction control systems, which is important for automatic transmissions. If the car is stuck in the snow, the impact of such a system should be minimized, but it will not be possible to turn it off completely.
Always follow the unit maintenance schedules specified by the manufacturers.
You cannot tow other cars or trailers; automatic transmissions are not designed for this. The unit has a certain reserve of strength. And if the gearbox does not immediately fail, then over time, operating the car under high load conditions will lead to problems. If you plan to use a trailer, then refrain from buying a car with an automatic transmission or buy a crossover or SUV.

Mode "N" or "Neutral"

The third main mode on the machine is the “Neutral” mode. In this mode, the car can move freely back and forth without engine input. Most often indicated by the “N” icon and is located between the “Reverse” and “Drive” modes.

The “Neutral” mode is provided in the automatic transmission as a service mode, in which the car can be moved short distances if the engine does not start. The instructions for many automatic transmissions indicate that in this mode you can tow the car over distances of 20-50 km at speeds of up to 20-30 km/h. However, in practice, if the service is located further than 3-5 km, it is better to immediately call a tow truck.

This recommendation is due to the fact that when the car is moving, oil must constantly circulate in the automatic transmission, and when the engine is turned off, the oil pump does not work. That is, some parts of the automatic transmission do not receive the necessary lubrication and may fail. A trip on a tow truck will not cost much, but serious problems with the automatic transmission can be avoided.

It is also necessary to note another common mistake that owners of cars with automatic transmission make, related to the “Neutral” mode. They often believe that the “Neutral” mode on an automatic transmission is the same as the “neutral” mode on a manual transmission and turn on this mode at the same time as they would turn it on on a manual transmission, for example, when approaching a traffic light. However, it is not. An automatic transmission is a much more complex unit and the “Neutral” mode is a service mode, which can only be used for its intended purpose, for example, for loading onto a tow truck and delivering the car to a service center. Any other use of this mode may cause automatic transmission failure.

Let's sum it up

As you can see, using an automatic transmission does not involve any difficulties, however, you must follow certain rules and adhere to a number of recommendations.

Only compliance with the conditions and rules of operation of the automatic transmission allows you to preserve the planned life of the automatic transmission (especially taking into account the fairly high cost of repairing the automatic transmission), and also not experience any problems or failures (shocks, kicks, jerks of the automatic transmission) while driving a car with this type of transmission.

Sources

https://VazNeTaz.ru/akpp
https://akppoff.ru/korobka-avtomat/kak-upravlyat-korobkoj-avtomat
https://uremont.com/publications/articles/kak-rabotaet-korobka-peredac-avtomobila
https://autodvig.com/kpp/korobka-avtomat-instruktsiya-19482/
https://KrutiMotor.ru/kak-upravlyat-avtomobilem-s-korobkoj-avtomat/
https://motoran.ru/interesnoe/kak-polzovatsya-korobkoj-avtomat
https://akppoff.ru/korobka-avtomat/kak-ezdit-na-avtomate
https://vvm-auto.ru/publikatsii/1328-kak-polzovatsya-akpp
https://www.zr.ru/content/articles/918525-5-samykh-lomuchikh-akp-ne-svyazyv/

How to find a fault

The operation of “electronic” automatic transmissions is controlled by an on-board computer, which is designed as a separate device or combined with a control unit.
It receives signals from various sensors located in and outside the automatic transmission. It processes information and, based on analysis, generates commands to actuators. This is how the automatic transmission is controlled. The computer also performs another function - monitoring and diagnosing faults. For all input signals there are acceptable limits for their change. If any signal goes beyond acceptable limits, the computer writes into memory a certain sequence of numbers - a code (Diagnostic Trouble Code - DTC) corresponding to this malfunction.

To read codes in the computer's memory, special diagnostic equipment is required - a scanner. The scanner allows you to read and erase codes, and you can also determine the readings of various sensors. The procedure for reading and identifying faults using codes is often called computer diagnostics.

In case of serious problems, the control system goes into automatic transmission protection mode. Emergency mode has different names: Limp In, Limp Home, Safe Mode. The operation algorithms of the control system in emergency mode are largely determined by the transmission model. In some cases, the system stops monitoring the quality of switchings, and they occur with “bumps”. In other cases, the transmission shifts into second or third gear and all gear changes are prohibited.

In some cars, emergency mode is accompanied by a flashing constant indication of one of the signals: “Hold”, “S”, “Check AT”, “OD OFF”. The signal can also be “Check Engine” or a symbol in the form of an engine outline. If none of these signals on the panel are illuminated, this does not mean that there are no fault codes in the computer's memory. But if there is a signal, then there are codes in the computer memory.

Emergency mode does not involve operating the machine; it only serves to get to the service center and fix the problem. If this is not done, it may turn out that due to a minor malfunction that was not corrected in time, the entire box fails.

What is Autostick or Tiptronic

This is an automatic transmission control system.
In addition to automatic, a semi-automatic control mode is provided, in which the driver gives the command to change gear, and the quality of these shifts is ensured by the control system. This mode has different names (Autostick, Tiptronic). In cars equipped with such a system, the lever has a special position in which the Autostick mode is activated. Regarding this position, there are two opposite, non-fixed positions of the automatic transmission lever. These positions are designated “+” (“Up”) and “-“ (“Dn”), respectively for shifting to a higher or lower gear.

What are adaptive transmissions

This term refers more to the control system, and not to the automatic transmission itself.
The development of “electronic” transmissions has led to the emergence of adaptive gearboxes. The developed control algorithms become more intelligent, which leads to the emergence of new characteristics. The on-board computer monitors the driver's driving style and adjusts accordingly. The operating algorithm takes into account the wear of friction control elements. This increases the resource and efficiency of the box.