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Automatic Transmission
general information At the time of pulling away the automatic transmission (AT) is acting as an ordinary clutch and during movement performs work on the gearshift lever. All covered in this manual model set AT Series 722.6 (cm. Specifications). The main units of the AT are the torque converter (torque converter), the planetary gear unit and a hydraulic or electronic control unit. To move to a different gear ratio in the planetary gear unit are applied by hydraulic disc brakes and clutch disk. The design of a typical AT Torque converter on the functions corresponds to hydraulic clutch. Its task is the implementation of the clutch when starting and changing gears. Transmission control system (also known as electronic synchronous shift) is part of a modified engine management system is installed only on models with the AT. The control system can operate in a special emergency (safe) mode with a limited range of switching, which switches when it detects a fault (the relevant information is displayed multifunction display). Switches to emergency mode allows you to drive away the car on their own a workshop to perform detailed diagnostics and necessary reconditioning. Based on the analysis of data from various information gauges (not necessarily directly related to the proper functioning of the transmission), transmission control module (TCM / ETC) selects the optimum in terms of efficiency, smooth shifting and so forth. Mode of operation of the AT. At a certain throttle position TCM can issue a command to lock the torque converter that control switching AT range only 4th and 5th gear, which contributes to a significant reduction in fuel consumption. AT only maintenance procedure, the implementation of which should be done on a regular basis, is to check the level of the working fluid (ATF), the order of execution which is set out in Chapter Current leaving and service. The need for regular replacement ATF is missing. Next to the cooling radiator installed cooler ATF. Based on data from the traditionally installed under the gas pedal sensor-switch activating the kickdown, TCM is to switch to an adjacent transmission currently used gear at full squeezing of a pedal that can significantly improve the dynamic characteristics of the car, such as when overtaking. There are several modes of transmission, each of which may be operated after moving the selector to one of the following positions: "P", "R", "N", "D", "1", "2", "3", " 4". On the model of the past few years the issue began to be installed electronic selector modules feature a consistent band selection mode of movement ?�D?� (1, 2, 3 and 4), when a transfer of the AT mode limit switching range (4, 3, 2 and 1) to the side push-ups the lever (D + / D-) (see. Section Starting up and switching automatic transmission). By using a special gauge-switch N / P to start the engine can be carried out only when the selector AT lever is in the "P" or ?�N?�, which helps prevent accidental pulling away when you try to start the car. In this chapter only the most common maintenance procedures AT lying within qualification of the average mechanic-fan. For more information on the design, operation and maintenance of the principles of AT 722.6 series can be found in the Guidelines 179 ("Automatic transmissions of modern cars") and 187 (?�Mercedes C-Class W-203") publishing ARUS.
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