How to check the oil level in an automatic transmission? For most vehicles, the oil level (ATF) in the automatic transmission (AT) is checked with the engine running and the Range Select Lever (RVD) in the "P" position. On the dipstick for measuring oil in automatic transmissions, as a rule, there are several marks. The top two, and sometimes the only ones, correspond to the normal level of oil heated to operating temperature (90 ° C).
Often this area of the probe is marked with a notch and / or the inscription "Hot". In order for the oil in the automatic transmission to warm up to operating temperature, it is necessary to drive 15-20 kilometers. After warming up the oil in the automatic transmission, install the car on a flat, horizontal platform. Pull the dipstick out of the transmission and wipe it dry. Then insert the probe back into the probe tube until it stops and remove it again. The lowest, dry place on the dipstick will correspond to the oil level in the automatic transmission. Sometimes there are also lower marks on the dipstick corresponding to the level of cold. This mark is intended for an approximate determination of the amount of oil filled in the event of an oil change.
Finally, the level, anyway, should be checked after warming up the oil. Often it is written on the dipstick in which position the high pressure hose should be checked for the level and type of oil used. There is a special case - Honda and Acura cars. They also check the oil level after reaching the operating temperature of the oil, but with the engine turned off. There are automatic transmissions in which the oil level is checked when the high pressure hose is set to the "N" position. Such transmissions are used on Mitsubishi, Proton and Hyundai front-wheel drive vehicles. Note that we are not talking about car models, but about transmission models.
So, for example, front-wheel drive boxes and Mitsubishi can be found on Chrysler cars and vice versa. If you have a Proton or Hyundai car, then the oil level in the automatic transmission should be checked in the "N" position of the high pressure hose. In the case of a Mitsubishi or Chrysler transverse engine, look at the automatic transmission from the wheel side. If there is a stamped side cover secured with ten bolts, then you have a Chrysler automatic transmission, and the oil level should be checked when the high pressure hose is in the "P" position. The absence of such a cover indicates that your car is equipped with a Mitsubishi automatic transmission, and the oil level should be checked when the high pressure hose is set to the "N" position. Also, in the "N" position of the RVD, the level is checked on Jeep Cherokee and Jeep Grand Cherokee cars with automatic transmission manufactured by Chrysler. But on some models of these cars, Aisin Warner automatic transmissions are installed, in which the oil level should be checked in the “P” position of the high pressure hose. To determine the type of box installed on your car, you can use the following method. The Aisin Warner automatic transmission has a rectangular sump, the dipstick pipe is welded directly to the sump on the side, and there is a drain plug at the back of the sump.
For Chrysler automatic transmissions, the pan is almost square, the dipstick pipe is installed in the gearbox crankcase and there is no drain plug. In addition, checking the oil level in the automatic transmission of VW, Audi cars with three-speed gearboxes should be carried out when the high pressure hose is set to the "N" position. In some automatic transmissions, instead of a dipstick, there is a control plug in the crankcase. The disadvantage of this is that to check the oil, you need to put the car in a "pit" or raise it on a lift. But there is an advantage: you will never pour oil into the automatic transmission, which is very important. Such plugs have ZF automatic transmissions, which, as a rule, are equipped with BMW cars. Moreover, on BMWs with five-speed gearboxes, the same plug also serves to fill the oil. For safety reasons, the level control in this case is carried out with slightly warm oil. This is European fashion. On the "Americans" we met such a level check procedure only in the 4T40E automatic transmission. It should be noted that there is an automatic transmission, which, in general, does not provide any devices for determining the oil level. This is the Mercedes 722.6 transmission, which is now installed on almost all cars of this company. The fact is that the container where automatic transmission oil is poured is connected to the oil pan through a bypass valve, the purpose of which is to maintain the required oil level in the pan. Therefore, the level of the filled oil is not as important as for other transmissions.
What are the dangers of low or high oil levels in automatic transmissions?
Too low an ATF level is dangerous because the pump, along with the oil, begins to capture air. The result is an air-oil "emulsion" that is highly compressible and has low heat capacity and thermal conductivity. The oil loses its most important properties and becomes compressible. The consequence of this will be a decrease in pressure in the control system, poor heat removal from the automatic transmission, deterioration in the lubrication of rubbing elements. Operating a car with foamed oil in an automatic transmission will quickly disable the box. I would like to note that you should not confuse individual large air bubbles in the oil on the dipstick (which sometimes happens) with foaming oil, which is a uniformly foamed liquid with very small air bubbles. Foaming the oil increases its volume, so when checking the level, it will be too high.
In this case, turn off the engine and let the oil settle for some time, and then, without starting the engine, check the oil level. If the probe turns out to be completely dry, then you can safely add a liter, or even two. The oil can also foam up the rotating parts of the automatic transmission if the level exceeds the allowable value. In this case, the rotating parts of the automatic transmission begin to dip into the oil and foam it. Foaming does not occur immediately after starting the engine, as is the case with a low level, but during movement, especially with high engine speeds. Both in the case of an underestimated oil level, and in the case of an overestimated level, foaming of the oil leads to an increase in its volume, and, as a result, to its emission through the gearbox breather. Looking under the car, you can often see there that the whole box is in oil.
Here is a case from practice. Ford Explorer came for diagnostics with a complaint that something incomprehensible was happening with the level. The level - that is, it is not, and the automatic transmission is all in oil. In a conversation with the client, it turned out that the dipstick was lost and replaced with a new one ordered by VIN from the dealer. When comparing the stylus and the stylus tube, it turned out that the stylus is much shorter than the tube. The ATF level was just at the level of the box axis. (Usually the level is approximately flush with the pan gasket.) Thus, the customer's complaint was caused by too high ATF levels in the automatic transmission.
The level is normal, but the ATF is foaming, what is the reason?
This is possible in case of damage to the filter seal or the filter itself.
The level is constantly decreasing, and there are no signs of oil leakage.
The prerequisite for such a malfunction is the presence of a vacuum modulator in some types of automatic transmissions - a special device that generates pressure proportional to the degree of vacuum in the engine intake manifold. Outwardly, the vacuum modulator resembles a similar device on a Zhiguli distributor. The modulator is connected to the intake manifold by a tube through which, in the event of a malfunction of the modulator membrane, oil from the automatic transmission enters the manifold and burns out. Typical representatives of cars equipped with an automatic transmission with a modulator: Ford Scorpio, Ford Sierra, Ford Explorer, Mercedes, front-wheel drive cars of the General Motors concern with four-speed automatic transmissions. It should be noted that since the beginning of the 90s, the use of modulators has been abandoned and replaced by electrical sensors.
Another reason for lowering the level of ATF in the automatic transmission in the absence of a leak may be a violation of the tightness of the cooling system. Many vehicles have an automatic transmission oil cooler built into the engine antifreeze cooler. If the built-in radiator is leaking, oil enters the engine cooling system, as a result of which the antifreeze turns into a pinkish emulsion.
How much oil should be poured into an automatic transmission?
Depending on the type, the automatic transmission can hold from 4.2 liters (DAIHATSU TERIOS) to 15.5 liters of ATF (FORD EXPEDITION). It must be borne in mind that when replacing, not the entire volume of oil is drained. Part of the oil remains in the channels of the control system, and, in addition, not all transformers have plugs for draining oil from them. Therefore, when draining the oil, part of it remains in the automatic transmission, but this is considered acceptable. If you want to completely change the oil, two or three oil changes are necessary.
How to determine what is filled in the automatic transmission, and what kind of oil to fill in when replacing it?
Gear oils differ in both color and smell. There are light yellow oils, and there are red shades (from light CASTROL to rich red ELF). It should be said right away that the color of the oil is determined only by the dye that is added to it so that automatic transmission oil can be distinguished from other oils used in the car. Nothing else determines the color of the oil.
In addition, after a short period of time, any oil acquires a transparent brown color. Given that when changing the oil, not all of its volume is updated, and also that the color and smell of the oil change during operation, it is practically impossible to determine its brand, even if it has changed recently. At least one, and preferably two-time oil change is necessary (in the absence of serious problems in the operation of the automatic transmission). You should use the oil that is specified in the operating instructions for the car. It happens that the type of recommended oil is also indicated on the dipstick. In addition, oil manufacturers produce posters and albums (they can be found in specialized stores) with a list of car brands and recommended oils, both motor and transmission.
Usually, the instruction manual recommends using a well-defined type of oil. Probably, there is not only a technical, but also a commercial justification for this. For example, Chrysler and front-wheel drive Mitsubishi (Hyundai) use Mopar ATF 7176, and the instructions indicate that this oil has increased frictional properties compared to Dexron or Mercon. But on the dipstick of the Dodge RAM and Jeep Grand Chrokee, you can find recommendations to fill in Mopar ATF 7176 or Dexron II. So it's still possible.
Another example: Mobil does not recommend mixing different types of oils, even its own production. And here is a quote from a bottle of Mobil Synthetic ATF: "Compatible with conventional ATF fluids" (Compatible with conventional automatic transmission oils). When it comes to changing the oil in the engine, the algorithm is simple. We go to a reputable store, choose an oil manufacturer (according to one criterion we know). From the entire range, we choose oil for gasoline or diesel engines, select the oil class according to API (so that it is not lower than in the operating instructions) and the desired viscosity according to SAE. All.
Why, when it comes to transmission, do we start looking for green oil without sparing time and money? Is it because the automatic transmission is a more exotic unit than the engine? The experience of repairing several thousand automatic transmissions suggests that the causes of breakdowns are more prosaic than mixing different types of oils when changing it. Transmission operating conditions are of paramount importance, and even the most expensive synthetics will not help if they are violated.
How often should automatic transmission oil be changed?
The oil change period depends on the type of automatic transmission, and, usually, under normal operating conditions, it is recommended to change it after 70 thousand kilometers of the car (or after 2 years), and after 25 thousand kilometers (or after 1 year) if the operating conditions are different from normal (hot climate, cold climate, operation in a metropolitan area, constant operation of the machine with a full load, etc.). For some expensive models (for example, the BMW 750), according to the instructions, an oil change is not provided at all. But no matter what, regularly (once a week) check the quality of the oil in the automatic transmission of your car.
You should adhere to the established replacement periods if during operation there is no significant change in the quality of the oil or you do not get into difficult driving conditions (get stuck, tow another car for a long time, etc.).
If the oil darkens and or acquires a burnt smell, it must be replaced without waiting for the scheduled replacement period. But not always replacing burnt oil can save the day. Most often, in these cases, an overhaul of the automatic transmission is required. When changing the oil in an automatic transmission, it is also necessary to change the pan gasket and filter.
In some types of automatic transmissions, filter replacement during an oil change is not provided, because. the filter is not accessible without removing and disassembling the automatic transmission (for example, Daewoo Espero, Nissan Maxima (with RE4F02A gearbox), SAAB 900 and 95, Volvo 850, front-wheel drive Opel models with a four-speed automatic transmission).
How to evaluate the quality of oil in automatic transmission?
Different types of oils differ in both color and smell. If your box has recently been repaired, remove the dipstick and note the color and smell of ATF. If during operation the color or smell has changed a lot, then there is a reason to contact the service to check the condition of the automatic transmission.
When buying a car with an "automatic", the oil should be transparent and not have a dark brown tint or a burnt smell. Drip the oil from the dipstick onto a white paper towel and check that the oil is easily absorbed and free from foreign matter. If the oil in a faulty automatic transmission was changed several times in a row before the sale, then after a careful analysis of the oil drop, you can still distinguish small black particles in it that are not in harmony with the transparent and bright oil. Often you can see a black coating on the dipstick. In this case, it is necessary to wipe the dipstick well and re-analyze the condition of the oil. If the raid did not reappear, then it means that the previous one was a consequence of the fact that the probe had not been used for a long time. It also does not hurt to look into the engine cooling system and make sure that the antifreeze is transparent and does not contain a water-oil emulsion. Keep in mind that you can find red antifreeze, which at first glance resembles automatic transmission oil.
What oils are used in automatic transmissions other than automatic transmission oil?
In front-wheel drive automatic transmission designs, as well as in some all-wheel drive transmission layouts (for example, AUDI, SUBARU), the main gear and differential are located in the same crankcase with the gearbox. This arrangement is called transaxle, in contrast to transmission, when the main gear is in the rear axle. If the main pair is in the same housing with the automatic transmission and is a hypoid gear, then oil for hypoid gears is poured into the differential housing (separate lubrication). In other cases, lubrication can be either separate or joint. In the case of a cylindrical, helical gearing in the main gear, as a rule, automatic transmission oil is used to lubricate it. It is not necessary to check the oil level in the differential with joint lubrication. In the case of separate lubrication, as a rule, there is a control plug or dipstick.
How to change the oil in an automatic transmission?
The sequence of actions for changing the oil is the same as for changing the oil in the engine. We drain the old oil, change the filter, fill in new oil. In most cases, the filter pan must be removed to replace the filter. Sometimes the filter is located inside the automatic transmission and is not accessible without dismantling and disassembling the automatic transmission. In this case, the oil change occurs without changing the filter. Along with the filter, the pan gasket also changes. Usually the filter and gasket are sold in one set (Filter kit).
On some models, the pan is placed without a gasket on the sealant. If the filter is made in the form of a fine metal mesh and is not damaged, then you can leave the old one by washing and blowing it with compressed air. Before installing the filter in place, check the quality of the seal of its mounting hole. The filter and pan mounting bolts should be tightened to strictly defined moments specified in the vehicle operating instructions. After you have filled in fresh oil, you must start the engine. Holding the machine with the brake, move the hose to all positions, pausing in each position for a few seconds. Then set it to the "P" or "N" position, check the oil level and bring it to the mark corresponding to the cold state of the oil. Finally check the level only after a run of 15-20 kilometers, when the oil temperature reaches the operating value. In the process of changing the oil, it is necessary to evaluate the presence of wear products located in the sump, on the sump magnets and in the filter.
A small amount of suspension in the oil, non-ferrous metal dust and a slight gray coating on the magnets can be considered the norm. Pieces of plastic, metals, the presence of black scales or clay-like deposits in the sump indicate the need for an overhaul of the automatic transmission, even if there are no complaints about the operation of the transmission yet.
Is the use of ATF additives justified?
Modern oils already have all the necessary additives in their composition. This question is often asked when problems arise in the operation of an automatic transmission. In most cases, problems in the operation of the automatic transmission are accompanied by increased wear of the friction controls. This is an irreversible process and neither oil changes nor additives will restore them. Therefore, by and large, overhaul is the only way to restore the transmission to working capacity.
What do the range selector symbols mean and why are they needed?
The range selection lever (RVD) of the gearbox has several positions, which have an alphanumeric designation. The number of these positions for different car models is different, but on all cars the high pressure hose must have positions marked with the letters "P", "R" and "N". Position "P" Selected when the car is parked for a long time. In this position of the high pressure hose in the automatic transmission, all controls are turned off, and its output shaft is blocked, so the movement of the car is impossible. This mode allows the engine to start. Position "R Reverse. Moving the lever to the "R" position while driving can lead to failure of the gearbox and other transmission elements. In this position, the engine cannot be started. Position "N" In the gearbox, either all controls are turned off, or only one is turned on. The mechanism for blocking the output shaft is turned off, i.e. the car can move freely. In this mode, starting the engine is allowed. For cars equipped with four-speed gearboxes, the RVD of the range has, as a rule, four forward positions: " D", "3", "2" and "1"("L").
It should be noted that if the high pressure hose is installed in one of these positions, the engine cannot be started. Range "D" - the main mode of movement. It provides automatic shifting from first to fourth gear. In normal driving conditions, it is recommended to use it. Range "3" - movement is allowed in the first three gears. It is recommended to use when driving on a hilly road or in conditions of frequent stops. Range "2" - movement is allowed only in first and second gears. Recommended for use on winding mountain roads. Switching to third and fourth gears is prohibited. Range "1" - movement is allowed only in first gear. This range allows maximum implementation of the engine braking mode. It is recommended when driving on steep descents.
On some car models, permission to use the fourth, overdrive, gear is carried out using a special "OD" button. If it is in the recessed position and the RVD is set to position "D", then upshifting is allowed. Otherwise, the inclusion of the fourth overdrive is prohibited. The state of the control system in this case is indicated by the "O/D OFF" indicator. If the use of overdrive is enabled, the indicator is off, and when it is disabled, it lights up.
What are the extra buttons (switches) for? What is winter mode?
On most modern vehicles with automatic transmission, several options for controlling gear changes are incorporated into the control system. These include - economical, sports, winter, etc.
economic program. The program is tuned to ensure movement with minimal fuel consumption. The movement of the car in this case is smooth, calm.
Sport program. This program is set to maximize the use of engine power. The car in this case develops, in comparison with the economical program, much greater accelerations. To implement an economical or sports program, a special button or switch is located on the dashboard or next to the range selection lever, which, depending on the brand of car, may be labeled "POWER", "S", "SPORT", "AUTO", "A / T MODE", etc.
Electronic control units of almost all modern cars have a special program for starting off on a slippery road (winter program). To activate it, there is also a special button or switch, which may be labeled "WINTER", "W", "HOLD", "*", etc. In the case of its action, various automatic transmission operation algorithms are possible, but, as a rule, in all cases, starting is carried out either from the second or from the third gear.
What is overdrive? Which of the modes is preferable in urban conditions drive or overdrive?
Overdrive in the terminology of American automakers means overdrive. Designated, usually, as "OD", either D or D in a circle. Overdrive is recommended for measured, economical driving on the highway.
Can the range selector be shifted on the fly?
It is possible, but not in all positions. It is strictly forbidden to move the high pressure hose to the "P" and "R" positions when moving forward. The lever can only be moved to both of these positions when the vehicle is at a complete stop. Violation of this rule can lead to serious damage to the automatic transmission. In addition, it is not recommended to move the high pressure hose to the "N" position while driving, since in this case the connection between the wheels and the engine is lost and sudden braking can cause the car to skid. And in all other provisions of the RVD can be easily translated. In some cases, it is even recommended to do it on purpose. So the transfer of the RVD from position "3" to position "2" will increase the efficiency of engine braking, etc.
Should the range selector be moved to "N" when stopped at a traffic light?
It only makes sense during long stops in traffic jams in hot weather, to reduce heat generation and prevent overheating of the gearbox oil. In other cases, this is not even recommended.
Do I need to use the parking brake when parked when the range selector is in the "P" position?
For reliable fixation of the car in the parking lot on relatively flat areas, a working mechanism for blocking the automatic transmission output shaft is quite enough. But if the car is on a slope, then the handbrake is required. Moreover, it is first necessary to tighten the hand brake and only after that set the high pressure hose to the "P" position. In this case, you release the automatic transmission output shaft blocking mechanism from the additional load associated with the tendency of the car to roll down.
How to determine the number of gears in an automatic transmission?
In Japanese cars, a four-speed automatic transmission can be identified by an additional button on the high pressure hose, which is labeled "OD OFF" or "Hold". If there is no such button, then most likely the automatic transmission is three-speed without overdrive. In European vehicles, the range select lever for three-speed automatic transmissions is marked with the symbols PRND21. Four-speed - PRND3. Five-speed - PRND4 ...
In American cars, the presence of a fourth (sometimes fifth) overdrive is indicated by a D symbol in a circle. With some experience, you can also determine the number of gears in practice, following the tachometer needle while the car is accelerating. Each shift will be accompanied by some reduction in engine speed. Only in this case, it must be borne in mind that the tachometer needle reacts in the same way to the blocking of the torque converter (however, the drop in speed in this case will not be as noticeable as during gear shifting).
Is it possible to skid on a car with automatic transmission?
Nothing criminal happens during slipping in the automatic transmission. Increased heat generation in the torque converter in this case can be critical if the cooling system has low efficiency (the automatic transmission cooling radiator is clogged with wear products).
How to tow a car with automatic transmission?
There is no single answer to this question either. For some cars there are very strict passport restrictions. For example, the Jeep Grand Cherokee is recommended to be transported only on a tow truck. Chrysler's front-wheel drive is a little easier. Vehicles with a three-speed automatic transmission can be towed at a speed of 40 km/h for a distance of 25 km, and with a four-speed automatic transmission at a speed of 72 km/h for a distance of up to 160 km. And yet, whatever the car may be, in the event of a faulty transmission, a tow truck is preferable.
The fact is that in automatic transmission lubrication is carried out forcibly, i.e. oil is supplied to each friction pair under pressure. If the transmission is faulty, then there is no certainty that lubrication is present. True, indirectly, the performance of the pump can be assessed. It is necessary to compare the oil level with the engine turned off and the engine running. If the level does not change, do not even think about towing. Carry out towing with the engine running and the high pressure hose in the "N" position.
There is another way to tow a car with a failed automatic transmission. Pour as much oil into the automatic transmission as possible, which will provide at least some lubrication of all its parts.
Can a trailer be towed by a vehicle equipped with an automatic transmission?
Allowed. But we must remember that the higher the load, the greater the heat generation in the torque converter. If you regularly use a trailer, consider installing an additional radiator in the automatic transmission cooling system. In addition, in the case of a long trailer towing, the use of overdrive is undesirable. It is better to do this on the "3" or "2" bands.
Do I need to warm up the automatic transmission before driving?
The first time after the start of the movement, it is recommended to avoid dynamic driving until the oil in all units has warmed up to operating temperature. In the cold season, before driving, it does not hurt to warm up the oil in the automatic transmission a little. To do this, it is necessary to move the RVD to all positions, lingering in each of them for a few seconds. Then turn on one of the ranges of movement, and hold the car for several minutes with the brake, while the engine should be idling.
What are the main advantages and disadvantages of automatic transmission?
Automatic transmission enhances driving comfort. The absence of the need to select the desired gear and shift gears allows you to focus on driving, which in a difficult traffic situation will not interfere even with an experienced driver. Due to the presence of a torque converter, the automatic transmission creates more favorable operating conditions for both the engine and the running gear, which increases their resource, and the automatic transmission control system prevents the engine and running gear from overloading due to driver errors. A car with 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 uneven ground, tk. The key can only be removed from the ignition switch in the "P" position of the high pressure hose.
The disadvantages of automatic transmissions include lower efficiency (due to losses in the torque converter) than manual transmissions, which increases fuel consumption. Although this is not always the case. Modern automatic transmissions in some driving modes can achieve higher efficiency than manual transmissions by maintaining optimal engine speeds and "intelligent" control of torque converter lockup. Another disadvantage is the slightly worse dynamic acceleration performance of a car with an automatic transmission than with a manual transmission, all other things being equal. The difference is not so great and for the majority of drivers is insignificant. And finally, a car with automatic transmission cannot be started except with the help of a starter. It should be noted that the vast majority of drivers who have experience in operating both types of transmissions, regardless of the level of income and driving experience, give unconditional preference to cars with automatic transmission.
What is a kickdown?
If the throttle pedal is fully depressed while driving, the gearbox will shift down one or two gears. This mode is recommended for obtaining higher acceleration values, which is useful, for example, during overtaking. Reverse upshifting in this case can only occur when the engine reaches maximum speed. If you release the throttle pedal, the transmission will return to normal operation. It should be borne in mind that on a slippery road during a forced downshift, the drive wheels may begin to slip, which can lead to a skid.
What does the automatic transmission cooling system look like?
As already noted, the main source of heat in the automatic transmission is the torque converter. Moreover, at high loads, the heat generation is quite large. The operating temperature of the transmission is comparable to the temperature of the engine, and may exceed it. Therefore, cars with automatic transmission have a special cooling system, the radiator of which is either built into the radiator of the engine cooling system, or installed separately and cooled by air flow. On older cars with a small engine capacity, you can find boxes that have an air cooling system. On the body of the torque converter there are additional external blades, with the help of which they organize the air flow to remove heat.
How to start the movement of a car with automatic transmission?
Before driving, always press the brake pedal, move the high pressure hose to the desired position, without pressing the throttle control pedal. After a light push, you can release the brake pedal and start moving by acting on the throttle pedal to do this.
What are the available methods for checking the condition of the automatic transmission? What is a "Stall Test"?
First, check the level and quality of the oil in the automatic transmission. Secondly, the time for switching on the gear when moving the high pressure hose from "N" to "D" or "R" should not significantly exceed 1 - 1.5 seconds. The inclusion of the transfer can be judged by a characteristic push. Pay attention to the quality of switching during break-in. When shifting gears, there should be no "bumps", vibration and extraneous noise. The moment of gear change should not be accompanied by an increase in engine speed. An experienced driver on the behavior of the car on the road can make a qualified preliminary conclusion about the state of the automatic transmission.
For reference: Tacho-Transmission provides free services - running a car by an experienced driver (test drive), reading fault codes and consultations. Another simple method for checking the condition of an automatic transmission is the Stall-Test. The essence of this test is to determine the engine speed when the car is completely braked and the throttle control pedal is pressed all the way down. By the magnitude of these revolutions, one can judge the serviceability of some elements of the automatic transmission. Immediately make a reservation that the Stall-Test should be performed by an experienced mechanic. Otherwise, you yourself can disable the automatic transmission. In addition, to analyze the performance of an automatic transmission, you need to know the nominal value of the engine speed during the Stall-Test, without knowing which this test will not give you anything.
Is it possible to do without automatic transmission repair if the car sometimes does not drive?
Owners of cars with "electronic" automatic transmissions, in the absence of movement, hope that all the problems lie in failed sensors, after replacing which everything will be fine. There may be problems with sensors, but as they say: "It's too late to drink Borjomi ...". The fact is that control algorithms do not provide for blocking movement in the event of any failures in the system. Even if all the wires and sensors are torn off from a working automatic transmission, the car will not lose the ability to move. There will be no good dynamics and gear changes, but you can go.
The lack of movement forward or backward, even periodically, indicates serious problems already in the mechanical part of the automatic transmission, and there is only one way out - repair. Sometimes you can hear the statement that the cause of all troubles can be a clogged oil filter in an automatic transmission. Like, replace the filter, change the oil twice - and all problems will disappear. That doesn't happen. The process of destruction of friction elements is irreversible. Burnt clutches are treated only by replacing them, new oil is not able to restore them.
What is the difference between "hydraulic" and "electronic" automatic transmissions?
The automatic transmissions themselves are the same both in the first case and in the second. The main difference concerns the control system. The control system can be conditionally divided into three parts: generating status signals for the automatic transmission and its controls; analytical and executive. In the case of a "hydraulic" automatic transmission, the hydraulics ensure the performance of all these three parts by generating the appropriate pressures.
In the case of an electronic automatic transmission, all signals (input and output) are generated electrically, and hydraulics are used only at the end of the chain of control signals. In addition, an electronic control unit (computer) is used to analyze the incoming information and make a decision. This makes it possible to make the automatic transmission control system more flexible, providing automatic transmission operating modes that are inaccessible to the hydraulic control system.
What are codes? Why is the "OD OFF", "Hold", "S" or "Check AT" light flashing? Why are there no gear shifts?
Here we will talk about automatic boxes with an electronic control system. The operation of "electronic" automatic transmissions is controlled by an on-board transmission computer, which can be made either as a separate device or combined with an engine control unit. The transmission computer receives signals from various sensors (speed, throttle opening angle, high pressure hose position, automatic transmission oil temperature, etc.) located both in the automatic transmission and outside it. It processes this information and, based on its analysis, generates commands (output signals) to actuators in the automatic transmission (solenoids). Thus, the operation of the automatic transmission is controlled.
The computer also performs another function - monitoring and diagnosing faults. For all input signals there are admissible limits of their change. If any signal goes beyond the permissible limits, then the computer writes to memory a certain sequence of numbers - a code (Diagnostic Trouble Code - DTC) corresponding to this malfunction. In addition, the computer controls the resistance of the output circuits (or the currents flowing through them, which is the same thing). For them, there are also permissible limits, when they are exceeded, the corresponding fault code is written to the memory.
In addition, the computer can compare the readings of the speed sensors of the input and output shafts of the automatic transmission, thereby controlling the gear ratio of the automatic transmission. Deviations of the calculated gear ratio from the given one is a sign of slippage in the automatic transmission friction controls, which is also fixed by the corresponding codes in the transmission computer memory. Unfortunately, the gear ratio control function is not implemented in all car models.
To read the codes in the computer's memory, special diagnostic equipment is required - a scanner. The scanner allows not only to read codes, but also to erase them, and it can also be used to determine the readings of various sensors of the automatic transmission control system. The procedure for reading and identifying faults by codes is often called computer diagnostics.
What happens after a fault code appears in the transmission computer memory? This is determined by the algorithm of the program on which the computer works. The reaction of the control system is ambiguous. When some codes appear, no tangible changes in the operation of the transmission will occur, while other codes may cause no gear changes. It all depends on which circuit of the control system failed. Some codes are informational in nature (for example, the code "the battery was disconnected"), while others lead to a change in the algorithm of the automatic transmission control system (for example, the code "break in the solenoid circuit").
In the event of serious problems, the control system switches to automatic transmission protection mode. This emergency mode has different names: Limp In, Limp Home, Safe Mode, etc. The operation algorithms of the control system in emergency mode are largely determined by the automatic transmission model. In some cases, the control system stops monitoring the quality of switching, and they occur with "bumps". In other cases, the box engages the second or third gear, and all gear changes are prohibited. In some cars, the emergency mode is accompanied by a flashing or a constant indication on the instrument panel of one of the signals associated with the operation of the automatic transmission: "Hold", "S", "Check AT", "OD OFF", etc.
In the case of a combined engine-transmission computer, this signal can be "Check Engine", or a symbol in the form of an engine outline. If none of these signals on the panel is lit, then this does not mean that there are no trouble codes in the computer's memory, but if there is a signal, then there are codes in the computer's memory. The emergency mode does not involve the operation of the car, it serves only to get to the service and fix the problem. If this is not done, then it may turn out that due to a minor malfunction that was not fixed in time, the entire automatic transmission leaves.
It must be borne in mind that the "electronic" box, in fact, is an actuating device. Problems with gear changes, poor dynamics, jerks, "bumps" can be caused both by a malfunction of the transmission itself, and by problems with wiring and sensors, as well as by a faulty transmission computer. Problems in the on-board electronics lead to the failure of the box itself, after the repair of which the situation will most likely repeat itself. And so on until the cause of the malfunction of the electronic part of the control system, which is not always located in the automatic transmission itself, is eliminated.
As a rule, cars arriving for repair have not one, but a whole range of faults. Qualified diagnostics will help to understand this tangle of problems. But one should not expect miracles from the diagnosis, although sometimes it is possible to quickly fix the problem and the box "comes to life" before our eyes. The possibilities of diagnostics have objective limitations. Computer diagnostics is far from equivalent for different types of automatic transmissions. Its capabilities can be assessed by looking at the full list of codes for this automatic transmission model. For some models, the list of all possible codes (and hence controlled parameters) consists of four items, while others have fifty.
What are adaptive automatic transmissions?
Again, this term refers more to the control system, and not to the automatic transmission itself. The development of "electronic" automatic transmissions has led to the emergence of adaptive gearboxes. The developed control algorithms are becoming more and more intelligent, which leads to the emergence of a new quality in the same, from a mechanical point of view, transmissions. The on-board computer monitors the driver's driving style, adjusting accordingly. In addition, the algorithm of operation of such a computer takes into account the wear in the automatic transmission of friction controls. All this leads not only to an increase in the comfort of a car trip, but also to an increase in its resource and efficiency.
What is Autostick (Steptronic, Tiptronic)?
This is an automatic transmission control system, in which, along with automatic, a semi-automatic control mode is also provided, in which the driver gives the command to shift gears, and the quality of these shifts is ensured by the control system. Depending on the manufacturer, this mode has different names (Autostick, Steptronic, Tiptronic), it is implemented only on cars with an electronic automatic transmission control system, and even then not on all.
In cars equipped with such a system, the RVD has a special position in which the Autostick mode is activated. Regarding this provision, there are two opposite, non-fixed provisions of the WFD. These positions are labeled "+" ("Up") and "-" ("Dn"), respectively, for upshifting or downshifting. The Autostick mode is semi-automatic rather than manual, as transmission computer, does not cease to control the actions of the driver and will not allow him, for example, to move from a higher gear, or to select a gear in such a way that the engine speed exceeds the allowable one. Otherwise, the complete illusion of a mechanical transmission. At the request of the driver, you can also switch to the normal automatic control mode by moving the high pressure hose to position "D".
automatic transmission in winter.
So. Automatic transmissions work perfectly and are extremely reliable in all seasons except winter. Therefore, I tell you how not to plant the automatic transmission if the temperature is below 15 degrees.
1) It is necessary to warm the car to WORKING! temperature. The oil cooler of the box and the engine is the same, and the box is farther from the engine, so the automatic transmission warms up LATER.
2) If you really can’t bear it, warm it up to at least 40, and then on the go, turning on 3rd gear and at a speed of no more than 40 km / h to working.
3) Before winter, change the oil and filter. The elementary truth - but the result is by no means elementary - saving money on repairs. Now, what will happen if this is NOT done.
In the automatic transmission control system ("brains") there are a number of valves, consisting of plastic and springs, which open from pressure. With thick oil, the pressure is higher and the plastic, if you rev with a slip, breaks. Consequence - a spring with fragments of plastic flies further and wedges the gears. Since the on / off drive gear is also made of plastic, it breaks. The result - the box does not shift gears either above 2, or quickly shifts from 2 to 4. If you ride like that, the clutches and repairs are planted in full.
For those who like to do everything themselves, I would generally advise reducing the working pressure by half a turn before winter.
based on ka.poehali.net
Important stages of car maintenance include regular checks of oil in the automatic transmission - the condition of the box, driving comfort and even fuel consumption depend on it. Often, machine breakdowns are associated with the poor condition of the transmission oil or a decrease in its level. Therefore, you can avoid many problems with the box without even changing the fluid, but simply by maintaining its level at a normal level. It is recommended to check it at least once a month, and you can do it yourself. The oil level in the automatic box of many modern cars is checked elementarily - using a dipstick.
Some motorists still do not know how to watch the oil level in an automatic transmission, especially for beginners. The main thing is to figure out where to look, and all this is described in detail in the instruction manual for a specific car model.
Oil deficiency symptoms
It is urgent to check the oil in the machine when certain signs are found that indicate its shortage. Experts advise to make a complete fluid change every 60-80 thousand kilometers. In this case, topping up the lubricant may be required earlier. According to the recommendations of automakers and automatic transmission developers, the level must be monitored approximately every five thousand kilometers. So you can add fluid in a timely manner, identify gasket wear or prevent other troubles.
If you do not control the level of engine oil, and it will noticeably decrease, certain signs will appear:
- from the transmission on a stationary car with a running engine, noise will be heard when you press the gas pedal;
- when changing gears, the car will twitch.
Do not bring the machine to the appearance of these signs - it is harmful for him. Timely checking the level and topping it up will extend the life of the mechanism. If you are interested, read the article about it on our website.
Where is the automatic transmission oil dipstick located?
If you have a car with an automatic transmission, you can check the oil level in it with a dipstick, but you need to find it first. It's easy to do - just open the hood and look around. If you see two bright loop handles, one of them is designed to check the oil level in the machine, and the second is needed to control the fluid in the motor. If there is only one handle, there is probably no dipstick for checking the oil in the machine on your car model (this happens). On machines with front-wheel drive, the dipstick located on the right in the direction of travel is designed to check the engine oil, and the dipstick on the left is responsible for the oil in the machine.
When there is no level control knob in the machine under the hood, to check the fluid, you will have to drive the car into a pit or lift, and then unscrew the control plug. If you check the oil level in the automatic transmission yourself, do it carefully, especially if the transmission has not cooled down after the trip.
Checking oil in boxes with a dipstick
The dipsticks for checking the oil level in the machine box usually have four notches:
- min and max for hot;
- min and max to cold.
These marks can be located on one side of the probe or be on different sides of it. When checking the oil level in a hot automatic transmission, the level should be between the upper notches, and when checking a cold box, the norm should be between the lower ones. It's simple: when warmed up, the transmission fluid rises a little.
On some machines, there are only two marks on the dipstick - min and max. In this case, the fluid in the box can be checked both with a cold and hot transmission. In both cases, the grease must be between the two marks.
On some automatic transmissions, for example, models AL4 and DP0, the oil rate can arbitrarily change within certain limits. This is due to the large number of cavities in the transmission, which can be filled with liquid, or can be emptied.
For an accurate and correct check of the oil level in an automatic transmission, it is better to repeat the procedure at least twice at certain intervals (1-2 days). If, after three or four checks, the level is between the minimum and maximum marks, the liquid in the machine is exactly as much as is required for its normal functioning.
Automatic transmission without a dipstick - how to check the oil?
Correctly checking the oil level in the machine without a dipstick is a little more difficult, but this task can also be done on your own. Such mechanisms usually have an overflow system consisting of two elements:
- special tube in the drain hole;
- plug that covers this hole.
The height of the tube determines the rate of lubrication in the machine. When unscrewing the control plug, excess oil that was above the level will flow out. This system was invented to prevent overflow when changing the lubricant in the transmission (this is harmful to the mechanism). At the same time, such a system creates inconvenience for the owner of the machine, who is unable to check the fluid level with a dipstick.
To check the level in this case, you will have to drive the car into a pit or use a lift. When unscrewing the drain bolt, be prepared for some grease to leak out of the hole. The leaked oil can be collected in a clean container and the degree of contamination of the transmission fluid and the entire assembly as a whole can be assessed.
If necessary, add the required amount of liquid through the neck and check its outflow. If the oil starts to drip, the level is normal, and if not, you need to add a little more. Thus, owners of a car with automatic transmission without a dipstick to check the level in it are forced to contact the service station.
The subtleties of checking the oil in the boxes of different cars
How to properly check the oil level in an automatic transmission largely depends on the model of the car, namely on the modification of the installed transmission. For example, Hyundai car owners should check the fluid in the machine when the lever is in the neutral position. In the same way, the liquid is checked for a Jeep Cherokee or Grand Cherokee with Chrysler automatics.
On machines with a transmission from Aisin Warner, the lubricant level is checked at the moment when the gear selector is set to the Park position. On Jeep cars, you can understand which box you have by the shape of the pallet: for Aisin, it is rectangular. A tube with a dipstick is welded to the pan, and there is a drain plug in the back of it. In most Chrysler machines, the pallets are square, and the dipstick tube is built into the crankcase - these boxes do not have drain plugs, that is, the level is checked with a dipstick when the selector is N.
All ZF modification boxes, installed mainly on BMWs, are equipped with lubricant overflow plugs. This is very convenient, since in this case it is impossible to pour more fluid into the transmission than required.
There are also automatic boxes in which it is simply impossible to measure the oil level inside. These include automatic transmission Mercedes 722.6, which is installed on almost all modern Mercedes. The thing is that the oil filling tank is connected to the sump by a bypass valve, which provides the ability to control the level of liquid in the sump.
For Aisin Warner automatic transmissions (the main manufacturer of automatic transmissions for Toyota), checking the ATF oil level takes place on a car with the engine running, in a strictly horizontal position, with a warm gearbox and the selector lever in the park position "P". To control the level of the working fluid, a level indicator is provided - a probe. Usually the dipstick is marked indicating the type of ATF fluid (sometimes there is a marking on the drain plug of the automatic transmission pan).
On most front-wheel drive vehicles, the dipstick located on the left side in the direction of travel displays the fluid level directly in the automatic transmission (the dipstick located on the right side in the direction of the car measures the engine oil level). For rear-wheel drive vehicles, with a longitudinal placement of the power unit, the probe is located in the opening between the rear wall of the engine and the engine compartment. With this arrangement, the probe is less noticeable!
The oil level in the automatic transmission depends on the temperature of the ATF fluid. When checking, the oil temperature should be 70-80 ° C, which is achieved after a trip of 15-20 km. If the vehicle has been driven at high speed for an extended period of time, or has been driven in a hot city environment, or has towed a trailer, the oil level in the automatic transmission cannot be accurately determined. Stop the engine and wait approximately 30 minutes for the oil to cool down to the correct temperature.
Before checking, let the engine idle with the air conditioning system turned off, press the brake pedal and move the selector lever through all positions, starting and ending with the “P” position, pausing in each of them for a few seconds to pump ATF working fluid throughout the automatic transmission system. Remove the level gauge from the automatic transmission guide tube, and wipe it dry with a clean cloth. Then insert the dipstick back until it stops and remove it again. Check the oil level and its condition according to the marks on the level indicator.
The normal fluid level (warmed up to operating temperature) should be in the HOT zone. Sometimes this section of the probe is marked with a notch. Do not overfill above the prescribed level!!! If the gearbox is cold, the level should be in the COOL zone. This mark is intended for an approximate determination of the amount of oil filled in the event of an oil change. Finally, the level, anyway, should be checked after warming up the oil. If the level is at the bottom of zone C/D, the automatic transmission must be topped up with oil through the dipstick guide tube.
A - cold oil level zone;
B - hot oil level zone;
C - area of low oil level on a cold gearbox;
D - area of low oil level on a hot gearbox
After 2000, Aisin Warner gradually switched to the production of automatic transmissions without a dipstick, changing the technology for monitoring and changing oil in Toyota automatic transmissions. Thus, the accuracy of setting the correct ATF fluid level has increased. Now automatic transmission with such a system is not threatened by oil overflow.
Many well-known automakers assure that the oil in the automatic transmission does not need to be replaced during the entire operational period. Regular car maintenance and timely control of the level in automatic transmissions reduces the risk of serious breakdowns. Drivers with car care experience can easily check the automatic transmission oil level in the garage without waiting for deterioration in performance. The operating instructions for a specific model contain detailed information on the procedure for carrying out control and measurement work.
Why check the oil level is necessary
In addition to reducing the friction force between the brake clutches, ATF grease performs the functions of removing excess heat, preventing the accumulation of precipitation on metal surfaces, cleaning parts from soot, chips, etc. If the amount of oil in an automatic transmission decreases, the risks of the following negative processes increase significantly:
- Destruction of metal surfaces of assemblies and parts.
- Stuck when shifting gears.
- An increase in temperature leads to a decrease in the mechanical strength of metal and polymer surfaces.
- Incorrect operation of the box (does not respond to switches or works late).
At the same time, the frequency of occurrence of problems and the intensity of their manifestation are steadily increasing. Even the slightest deviations in the operation of the transmission are not recommended to be ignored. If there are alarming symptoms, the first step is to check the oil in the automatic transmission. If no leaks are found, but the oil has changed in color and consistency, it is recommended to urgently contact the nearest service station. Delay in both diagnosis and repair can lead to irreversible changes in the gearbox.
The oil level in the automatic transmission is not only reduced, it should also not exceed a predetermined limit. Improper filling with oil can lead to unforeseen consequences:
- when the edges of the rotating parts are reached, the solution begins to foam, the workers
- oil characteristics are rapidly declining, lubricant production is sharply accelerated;
- problems similar to a lack of oil appear;
- excess oil flows out through the breather;
- the body of the automatic transmission is covered on the outside with oil streaks.
How to check the oil level in an automatic transmission with a dipstick
Thanks to measuring the oil level, the owner of the car can detect a leak in time, as well as the degree of wear of the lubricant in the automatic transmission. The information obtained is necessary for the correct choice of car repair methods. The design of the new automatic transmission differs significantly from the usual mechanical devices. Many drivers have certain difficulties when trying to determine the oil level in an automatic transmission for the first time.
As a rule, the dipstick for measuring the oil level in an automatic transmission is easy to see on the box body. Automakers have tried to visually highlight the dipstick against the surrounding body parts. Its handle is marked with a contrasting color (yellow, red, etc.).
The procedure for measuring the oil level in an automatic transmission with a dipstick
- Place the vehicle on a level surface without a slope.
- Move the gear lever () to the “Parking” point.
- Warm up the engine to plus 90 ° C.
The probe has special control notches MAX and MIN. They are located in pairs on opposite surfaces of this tool and are designed to measure the oil level in various temperature conditions (COLD-cold, HOT-hot). The "cold" test is carried out at an ambient temperature above 0°C.
The oil level in the automatic transmission is considered normal if the oil mark is between the minimum and maximum marks.
We measure the oil level in the automatic transmission without a dipstick
There are cars (as a rule, these are European models), the design of which includes only one control probe - for measuring gasoline in the fuel tank. Here, the transmission oil level in the automatic transmission is checked without using a special oil dipstick.
In this case, the design of modern automatic transmissions provides for the installation of a special tube in the box sump. The protective tube is designed to remove excess and control the state of ATF transmission oil by the smell of burning, dark color, consistency density, and changed chemical composition.
Verification steps:
- after a thorough analysis of the quality of the oil inside the automatic transmission, the tube is screwed into place;
- a portion of fresh oil is added through the filler hole using a special elastic hose of a suitable diameter and a funnel;
- if nothing flows out of the control tube, you need to add lubricant until oil drops appear (the box begins to get rid of unnecessary excess).
Independently checking the level of oil in the automatic transmission does not seem to be a difficult procedure. However, before carrying out this event, you need to familiarize yourself with some of the nuances. If they are not taken into account, large errors are obtained when measuring the oil level.
Experienced motorists know that inside the automatic transmission in the oil compartment there are multiple cavities in which gear oil is collected in large quantities. As a result, the probe readings are not always reliable. Measurements are considered correct if the oil level is measured not once, but in several visits (in one or two days). After that, the arithmetic mean of the readings is calculated.
The dipstick for measuring the level of ATF transmission oil in appearance is very similar to a control device designed to check the oil in. Before operation, it is necessary to carefully examine this device so as not to confuse it with a “motor brother”.
In cars with rear-wheel drive, the automatic transmission oil dipstick can be difficult to find, because it is located between the passenger compartment wall and the engine compartment. After a thorough examination of this space, it will definitely be found.
Regardless of the design of the machine, it is necessary to measure the oil level only after the box has been thoroughly warmed up.
The oil level in an automatic transmission can be checked at its operating temperature, as well as at room temperature of the oil. First, we will consider the first way to check the oil level in an automatic transmission - at operating temperature. This process is pretty easy. So, first of all, you need to start the engine and warm up the oil to operating temperature. To do this, you will need to drive approximately 15-20 km. The next step is to install the car on a flat horizontal surface. The wheels must be locked with the brake while the engine must continue to run. In order to fill the hydraulic system with oil, the driver must press and hold the brake pedal and move the gear lever to all positions gradually. Next stage. We put the automatic transmission in the “pakring” position (P) and release the brake pedal. You need to pull out the dipstick, wipe it well, then put it in place and pull it out again to dry it again. There are marks on the surface of the dipstick that show the oil level for two types of engine - cooled and hot. With this check, the oil level should indicate the sign hot (HOT). Sometimes, depending on the car, only the COLD (cold) mark is applied, because you need to use a different automatic transmission position (for example, neutral). The third stage of examining the oil level with a dipstick. It also has notches such as ADD (need to be added) and FULL (enough). If the label is on ADD, then you just need to add it. If you added oil, be sure to check its level a second time. The last action is to insert this probe back into its place, closing the lid very tightly. This will prevent dirt or water from entering the gearbox assembly. Regarding the second method of studying the automatic transmission oil level (degree of room temperature), the process is almost the same as at operating temperature. The only difference is the oil temperature (it must be cold) and the oil level, which must occupy the ADD position on the device. It is very important not to forget that you must not overfill the gearbox system with technical oil when measuring its level. If this happens, then the following problems await you. First, the temperature of the lubricant will change and it will foam. This will cause the engine oil to splatter the entire box, as there is too much of it, and will flow out. Thus, the automatic transmission stops working. When the amount of engine oil is not sufficient, then certain problems also arise - a decrease in the oil resource, but this is not the worst thing. It ceases to be oil and, mixing with air, turns into an emulsion. In this state of the oil, pressure drops in the system occur, heat transfer from the automatic transmission is disturbed and the transmission disappears.
How to check the automatic transmission oil level without a dipstick
Sometimes it is possible to check the oil level without using a dipstick. A gearbox without a dipstick has a different structure. Its system is a drain hole that is firmly closed with a stopper and prevents oil from flowing out. This hole is connected to a cream pipe, with the help of which the oil level is determined. So, for starters, you need to put the car on a lift or drive it into a pit. So you can see the plugs on the gearbox and at the same time do not disturb the horizontal position of the machine. Before you open the lid, locate the oil container, as oil often gets into these plugs and it can simply slosh to the ground. With the help of leaked oil, you can determine the degree of contamination and the need to change the oil in the gearbox. But not everything is simple here. First you need to open the drain hole and pour oil into the automatic transmission neck. The oil level in the gearbox will only be considered normal if it flows out of the drain hole. Otherwise, you need to fill in the oil until it starts to flow out of the drain hole. Due to such a complex process, many car owners avoid checking the oil level frequently.
Computer approach for the study of automatic transmission oil
There is also a technical approach to studying the level of engine oil. There are such types of automatic transmission computer diagnostics: visual viewing, oil level studies, automatic transmission diagnostics using on-board systems, scanner examination, and so on. Standard process for diagnosing automatic transmission oil. First, a visual inspection of the machine is done, especially attention is paid to the quality of the oil at the moment - it should not stink of burning and be very black. Only then, using special instruments and equipment, computer diagnostics are carried out. An interesting fact is that each car has a special connector that is used in computer diagnostics. Various devices are connected to the machine, which can determine malfunctions. The main equipment for checking the oil level of the gearbox is a scanner. It reads information about the gearbox and points out ways to troubleshoot. Now technology is developing very quickly and current devices can see the damage code. These codes are located in the automatic transmission control system. With a computer check, the endurance and operation of the automatic transmission, sensors and switch system are first diagnosed. Then they are taken for testing the torque converter and the engine. This is a comprehensive check with the help of which they not only find a malfunction, but also draw up an action plan for repairing the machine.
What should I do if the equipment does not help identify errors in the operation of an automatic transmission?
There are cases when under normal conditions, even with equipment, it is difficult to determine a failure in the transmission system. In such situations, a test drive is prescribed - the operation of the automatic transmission control system is fully checked. And only after such a test, you need to follow all the instructions and recommendations of specialists, because even the smallest mistake in the system can lead to the complete collapse of the automatic transmission system. And so, if computer diagnostics are powerless, then a mechanical examination is a lifeline for checking automatic transmission oil. After all, if the computer did not find anything, and there are problems with the car's gearbox (jerks or bumps when switching), they must be solved. You can’t start this business, otherwise you will pay a lot of money for repairs. Our recommendation is to check the automatic transmission oil level once a year.
