How to adapt the automatic transmission

One of the gaps in the knowledge of car owners with an automatic gearbox is such a characteristic as adaptability. Even without knowing about this function, drivers in the course of daily operation actively adapt the automatic transmission, adjusting its mode of operation to their individual driving style.

After the adaptation settings have been made in the service center, the automatic transmission continues to adapt throughout the further operation.

What is automatic transmission adaptation and why is it needed

The concept of adaptation in a broad sense means the adaptation of an object to changing external and internal conditions. In relation to cars, this term refers to the adjustment of the operation of the automatic transmission depending on the individual driving style, the corresponding modes of operation of the engine and brake system, the operating time and degree of wear of the mechanism parts.

Automatic transmission refers to the classic version of a hydromechanical gearbox, including an automatic planetary gearbox and a hydrodynamic torque transformer, as well as robotic gearboxes. For such a variety of mechanisms for changing the gear ratio of a transmission without human intervention, as variators, the topic under consideration does not apply.

For a hydromechanical gearbox, the adaptation procedure is based on adjusting the settings of the automatic transmission electronic control unit (ECU). The storage device contains logic programs that receive information from sensors or control units of other systems. The input parameters for the ECU are the speed of the crankshaft, output shaft and turbine, the position of the gas pedal and the Kick-Down switch, the oil level and temperature, etc. The commands generated in the ECU are transmitted to the actuators of the hydraulic control unit of the gearbox.

Sectional view of a hydromechanical gearbox.

Earlier automatic transmission models were equipped with permanent storage devices that did not allow changes to the control algorithm. The possibility of adaptation was realized by the development of reprogrammable storage devices used in almost all modern automatic transmissions.

The programmer of the automatic transmission ECU is configured to take into account many different operating parameters, the main of which for adaptation can be considered the following:

1. Acceleration dynamics, expressed in the sharpness of pressing the gas pedal. Depending on it, the adaptive machine can tune in to a smooth, maximally extended gear shift or to an accelerated one, including jumping through the steps.
2. The driving style to which the program responds by the frequency of changes in the position of the gas pedal. With a stable position of the accelerator in the process of movement, higher gears are switched on to save fuel, with a “ragged” mode of movement in traffic jams, the machine switches to lower gears with a decrease in the number of revolutions.
3. Braking style. With frequent and sharp braking, the automatic transmission is configured for accelerated deceleration, the manner of smooth braking corresponds to smooth gear shifting.

Although the process of adapting the operation of the hydromechanical automatic transmission with the help of the ECU occurs in a constant mode, in some cases it is necessary to reset the existing settings and reconfigure the parameters. This procedure is recommended to be performed when changing the owner (driver), in case of incorrect operation of the unit or after repair, if the oil was changed during troubleshooting.

Reset the previous adaptation on the ECU.

Experienced drivers practice reconfiguration when switching from the winter to summer operation and vice versa, when returning from long trips to the urban cycle, after traveling with the maximum vehicle weight load.

For robotic gearboxes, the purpose of adaptation is to adjust the operating mode depending on the degree of wear of the clutch disc. This procedure is recommended to be carried out periodically in a planned manner, in the event of failures in its operation, after the repair of the transmission is completed. The individual driving style in this case is rather the cause of diagnosis and adaptation.

How to make an adaptation

The adaptation procedure consists in setting new parameters for the reprogrammable automatic transmission computer. The principle of operation of these devices is based on the same logic circuit, but each car model requires an individual approach and algorithm of actions.

Most ECUs are capable of being reprogrammed in two adaptation modes:

1. Long-term, which requires a car run from 200 to 1000 km. At this distance, the ECU takes into account and memorizes the average modes of operation of systems and mechanisms. In this case, the driver does not require any additional or purposeful actions (except for movement in his usual style), and for components and parts this method is more gentle and recommended.
2. Accelerated, performed at a distance of several hundred meters and for several minutes. It is worth using such a mode, for example, during a sharp transition from a smooth suburban mode to a “torn” city mode with traffic jams, fast acceleration and sharp braking. If such transitions are infrequent, it is better to leave the adaptation setting to the ECU.

Carrying out adaptation of the automatic transmission in the service center.

Reset old values

In some cases, adaptation requires a preliminary reset of existing settings. Sometimes the term “zeroing” is used for this operation, although reset only means returning to the original program parameters for this automatic transmission model.

The automatic transmission adaptation reset is carried out after the gearbox is repaired or when it does not work correctly, which is expressed in slow gear shifting, jerks or jerks. You can also return to the factory setting of the automatic transmission when buying a used car in order to feel the standard conditions and operating modes laid down by the manufacturer.

To reset, it is necessary to preheat the box oil to operating temperature, and then perform the following sequence of operations:

• turn off the engine for a few minutes;
• turn on the ignition, but do not start the engine;
• sequentially with an interval of 3-4 seconds, perform 4-5-fold switching of the box between selector positions N and D;
• turn off the engine again.

To adapt the robotic box, it is necessary to use special diagnostic equipment to determine the state of the clutch units, clutch and gear control drives, control units and software adaptation of the system.

How long to wait for the result

The result of resetting the settings can be assessed after 5-10 minutes, preferably on a flat and free road, without sudden accelerations and braking. The result of this stage of adaptation is the softness and smoothness of the mechanics, the absence of shocks and delays when shifting gears.

Accelerated adaptation of the automatic transmission

Accelerated adaptation, otherwise called forced, can be performed in two ways, each of which implies the presence of a reliable algorithm of actions and a professional approach. Forums and discussions of owners of various brands show that not everyone manages to find a source on their own and achieve the desired result with it.

The first way is to flash the ECU, which should be trusted to service specialists armed with the necessary devices and software.

The second way to accelerate adaptation is to relearn the ECU on the go, which also requires the original technical information for the adaptable box. The algorithm includes sequential and cyclic operations (individual for each brand and model) for warming up, stopping and starting the engine, accelerating to the specified speeds, mileage and braking.

Problems during the procedure

The adaptation of the automatic transmission has become possible due to the emergence of complex electronic systems that continue to improve and develop. The complexity of these systems, aimed at improving driving comfort and safety, is fraught with potential risks and possible problems.

The problems arising during the operation of the automatic transmission or its adaptation are in most cases associated with the operation of the computer, with failures of its program logic circuits or technical elements. The reasons for the latter can be short circuits as a result of a violation of the insulation or integrity of the housings, overheating or ingress of moisture, oils, dust, as well as power surges in the vehicle's on-board network.