Audi A4, S4

since 2000 of release

Repair and car operation

Audi A4, S4
+ Introduction
+ Governing bodies and receptions of safe operation
+ Current leaving and service
+ Engine
+ Systems of cooling, heating and air conditioner
+ Power supply systems, release and decrease in toxicity of the fulfilled gases
+ Systems of electric equipment of the engine
+ Manual box of gear shifting
- Automatic transmission
   Search of malfunctions - the general information
+ Coupling, power shafts and differential
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment


Automatic transmission

The car can be equipped with an automatic transmission or a box with besstupenchaty gear shifting of Multitronic.

The box can be removed without engine removal. To remove a box it is necessary at its replacement or repair. It is not recommended to carry out box repair in house conditions.

Management of transmission is in detail described in Head Governing bodies and receptions of safe operation.

Procedures of removal and installation are similar to removal and RKPP installation, the description is provided in the Section Removal and check point installation.

Automatic transmission, in the course of a troganiye from a place, carries out function of ordinary coupling, and during movement performs work on gear shifting.

The AT main hubs are: torque converter, planetary reducer and hydraulic or electronic control system. Hydrodriving disk brakes and disk coupling are applied to transition to another transfer the relation in a planetary reducer.

The torque converter on the functions corresponds to hydraulic coupling. Its task includes coupling implementation at a troganiye from a place and gear shifting.

Management of switching is carried out by the electronic block. Thus the electronic block for the correct management uses various information which allows for each mode of movement of the car and depending on desire of the driver to choose the most optimum transfer relation.

Switches of programs, such as «Economy» or «Sport», are not required, since the control unit automatically, on a movement mode, establishes switching points. At definition of points of switching resistance to movement, such as, lifting or descent from the mountain, towage of the trailer and existence of a head wind are considered also.

The control system can work in a special safe mode to which passes at detection of any malfunction. Thus operating modes of transmission are limited, and the car can be delivered under the own steam to repair shop. Upon transition of a control system to a safe mode on a control panel the control lamp (address to Head Governing bodies and receptions of safe operation) lights up.

Analyzing information arriving from various sensors (not only the sensors which are directly related to transmission), the control system chooses optimum from the point of view of profitability, smoothness of a course etc. a box operating mode. At the certain provision of a zaslonka of a throttle the control system can block the hydrotransformer in such a manner that the fourth and fifth transfers will join only. It reaches considerable decrease in consumption of fuel.

The unique regular procedure of service of a box is check of level of working liquid (address to the Section Check of level of oil of automatic transmission). Regularly to change transmission liquid it is not necessary.

Near a radiator of system of cooling the cooler of transmission liquid is established.

There are some operating modes of transmission, each of which can be involved after moving of the selector to one of the following provisions: P, R, N, D, S (address to Head Governing bodies and receptions of safe operation).

The engine can be started only if the selector is in situation P or N. It is made to prevent car movement in start attempt (if the selector is established in one of other provisions). Analyzing information arriving from sensors, the control system resolves or forbids engine start. The locations of various relays are specified in Head Onboard electric equipment.

The selector of 5-step AT Tiptronic near a path of provisions of automatic switching has the second path of step-by-step (consecutive) switching. The sports steering wheel can be equipped with the corresponding keys. Such switching is accepted in sports cars.

In the presence of Tiptronic box the driver can make compulsory switching on higher and lower transfers. In comparison with manual switching of Tiptronic more with comfort also it is protected against erroneous management. So for example, switching on lower transfer is made only if turns thus do not leave for certain borders.

In the presence of malfunctions of entrance signals or electromagnetic valves switching on the emergency program is made. At the same time arisen malfunction registers in memory of malfunctions. Information from memory can be считана the special device.

Automatic transmission of Multitronic with besstupenchaty gear shifting

Besstupenchaty AT Multitronic

Multitronic - besstupenchaty transmission of CTV with smoothly changeable transfer relation which provides not only effective use of engine capacity, but also provides good dynamics and comfort of driving.

Basic element of Multitronic system is klinotsepny the variator. By means of a variator the transfer relations between a troganiye mode from a place and the last transfer change smoothly. Thanks to it the engine, irrespective of a mode of movement, moshchnostny or economic, works in an optimum mode corresponding to it. The variator consists of two conic pairs connected with each other by a lamellar chain. As in each pair of disks the conic disk moves an electrohydraulic drive, working diameter of a chain and thereof the transfer relation smoothly changes. Besides, in Multitronic coupling cooled by oil which excludes not only typical shortcomings of the converter of a torque is applied, but also gives the chance various options of a troganiye from a place. The option gets out an electronic control system according to desire of the driver which is distinguished on nature of moving of a pedal of gas. Besides, elektronnoupravlyaemy coupling realizes a stable mode of creeping movement which is a comfort element. The electronic control system, besides, provides an identification of the driver and a state of environment and works with the dynamic program of regulation of DRP. The specified program determines by nature of moving of a pedal of gas, whether the driver in dynamic or in an economic mode wishes to move.

If the driver gives full gas (kik-Down), the electronic control system is switched at once to sports control mode and lowers transfer that provides necessary high number of turns of the engine. At a normal mode of movement the choice of the optimum transfer relation, and all its changes, unlike step switching of AT is made, are carried out smoothly, without breakthroughs and is imperceptible. Electronics distinguishes also liftings and descents and compensates additional loading or increases the moment of braking by the engine.

In a mode of manual switching of 6 control units of the fixed transfer relations (transfers) brought in memory can smoothly be switched by the lever of the selector or buttons on a steering wheel.