Audi 80/Avant (B4)

Since 1991-1995 of release

Repair and car operation

Audi 80/Avant
+ The description
+ Engines
+ System of release of the fulfilled gases
+ Cooling system
+ Fuel tank and the fuel pump
+ The air filter and воздухозаборные channels
+ Injection system
+ Coupling
- Transmission and transmission
   Removal and installation of a mechanical transmission (КП)
   Noise in a transmission
   Automatic transmission (АКП)
   Electronic control АКП
   The main transfer
   Power shafts
   Check of cuffs of power shafts
   The list of malfunctions
+ Suspension bracket and steering
+ Brake system
+ Antiblocking system of brakes
+ Wheels and tyres
+ Kuzovnaja electrosystem
+ Ignition system
+ Illumination
+ Signalling devices
+ Devices and auxiliary devices
+ Heating and ventilation
+ Body elements
+ Search of malfunctions
+ Specifications


Electronic control АКП

The scheme does by more evident communications between the block of valves of switching (1) АКП, the lever of the selector (2) multipurpose switch (3) and the electronic block of management (4). The manual valve (5) is set in motion by directly lever of switching.

Entrance signals

The management block processes numerous signals from various knots; the information arrives from:

    The lever of selector AKP with the multipurpose switch. Management of inclusion of headlights of a backing, starter blocking depends on lever position at the included mode of movement and management of system of change of a mode of movement. Button "Sport" including the sports program of switching. Potentiometer throttle заслонки about position throttle заслонки. This acquaintance on system of injection an element serves for definition of the moments of switching. The gauge of speed in АКП for definition of speed of movement also for the switching moments. In case of malfunction of this gauge the management block uses frequency of rotation of a shaft of the engine (from the Hall gauge) as a spare indicator. The gauge of limiting position of a pedal of an accelerator in тросовом "a gas" drive; he informs, if the accelerator pedal has been completely squeezed out. In this case switching on the raised transfer occurs later, in need of АКП switches to two ranges downwards. The switch of a signal of braking for removal of blocking of the lever of switching. The lever of switching from position P or N in one of movement ranges can be moved only at the squeezed out pedal of a brake. The gauge of temperature ATF informing on temperature of a liquid in АКП. Considerable heating ATF can come a consequence of strong distinction of number of turns between the engine and АКП. If in the management block the signal the raised temperature, arrives

АКП in separate ranges switches to the raised transfer later. It reduces проскальзывание in the hydrotransformer and reduces temperature ATF – then again there is a switching on the usual program of movement.

Management of switching processes

If you move the selector lever in position D being under the pressure of ATF gets to so-called valves of switching in the block of valves which, in turn, гидравлически operate multidisk муфтами and multidisk brakes. The block of management Digimat regulates pressure by means of electromagnetic valves and thus defines the moment of time for switching on raised or a hill-climbing gear, and also switching transitions. Communication with the block of management of systems of injection/ignition is simultaneously supported – at switching on the raised transfer the moment of ignition moves back that switching transition has passed smoothly a little.

Commands from the management block get further on a magnet of blocking of the lever of switching, the relay of blocking of a starter and headlights of a backing and the light indicator in button "Sport". If car Audi 80 is equipped by system of regulation of speed a food on it starts to move with the management block only when one of ranges of advance and speed is included for the first time has reached borders of 30 km/h.

Independent diagnostics

The block of management АКП can distinguish and write down arising malfunctions. The control program observes of entrance and target signals of almost all gauges and knots, and also behind their electric chains. Arising malfunctions register in long-term memory of the store. At corresponding check in a workshop memory of the store is read out by means of the special device. Possibilities of check of memory of the store in house conditions do not exist. Even if you assume malfunction presence in management АКП interrogate memory of the store of malfunctions you can only in workshop Audi.

Operation in extreme conditions

If the management block has fixed the malfunction essentially influencing functioning or if the block of management it is switched in a mode operation in extreme conditions is faulty. For this purpose there are two programs:

    As well as before failure detection, АКП it is switched automatically on raised or a hill-climbing gear, but jerks at switching become considerably more expressed. АКП it is not switched any more automatically on raised or a hill-climbing gear. In positions of the lever of selector "D", 3 and 2 on hand there is only a third range. Only in positions 1 and R the chosen range really joins.
    In both cases it is necessary to visit urgently workshop Audi where memory of the store of malfunctions first of all will be interrogated.

Check АКП

АКП almost does not give possibilities for display of own initiative in house conditions. Purposeful checks, however, help to estimate a cause of defect that is not in the last instance interesting at purchase of the second-hand car:


    At malfunctions first of all it is necessary to check up level ATF in АКП. If ATF on a tip probeа smells burnt down, means, there is serious damage АКП. In this case are defective multidisk муфты or brake tapes. During a trial trip it is possible to check up the switching moments. From this, how there are switching processes, it is possible to draw a conclusion on condition АКП. Regulation тросового a drive of gas with the integrated gauge of limiting position of a pedal of an accelerator – the important condition for excellent job. The same it is possible to tell about regulation тросового a drive of the lever of the selector.

Supervision over switching processes

During a trial trip you should pay the attention to switching processes:

    Switching on the raised transfer: at short squeezed out pedal of an accelerator switching is almost imperceptible; at completely squeezed out pedal of an accelerator (at трогании from a place or during movement) gear changes become more appreciable, but the raised transfer should join smoothly. Short-term increase of turns at change of transfers specifies in malfunctions in which it is necessary to be engaged more densely. Switching on a hill-climbing gear: at the released pedal of an accelerator (at movement накатом) and very low speeds almost imperceptibly. Jerk at switching on a hill-climbing gear on incomplete or full "gas" is quite normal. Switching on a hill-climbing gear the selector lever at the released pedal of an accelerator lasts 1—2 with. If at switching by the selector lever the accelerator pedal change of transfers should occur immediately is simultaneously squeezed out.

 The help: Audi 80 with an automatic transmission it is impossible to tow further, than on 50 km, differently there is no greasing АКП. For the same reason at towing it is impossible to exceed the maximum speed in 50 km/h. In сомненительных cases it is better to choose shorter way or to cause эвакуатор.

Removal АКП

The car is necessary for raising and reliably to fix. The big garage jack for поддерживания and lowerings downwards very heavy АКП also is required to you.


    To disconnect the accumulator. To disconnect a wire tip to the tachometre gauge. At models with the 6-cylinder engine to remove the inlet channel. For this purpose to disconnect vacuum hoses, to remove воздуховодный a hose and to turn out fixing bolts. At models with divided bulk branch pipe ATF to weaken it above and to extend. The bottom part of a branch pipe to stop up with not fibrous rag. To turn out the bolts connecting the engine and АКП which it is possible to reach from above. To raise hoses of system of cooling. To bring under the engine reliable support, to prevent overturning. To turn off the bottom panel of a motor compartment. To remove thermal protection of a leading semiaxis. To remove кузовные traverses below an exhaust pipe or каталитических neutralizers (depending on engine type). To remove exhaust pipes (at models with the 6-cylinder engine together with catalyticи neutralizers). To disconnect power shafts from a transmission (without allowing to fall it). To remove a starter. Thanks to it access to fixing bolts of the hydrotransformer opens. To substitute capacity under болтовые connections of ATF-lines. To separate the pipeline to cooler ATF at level of the oil pallet. To turn off fastenings for pipeline ATF and to take hoses aside. To weaken in total three bolts of the hydrotransformer from outside the engine. For this purpose to adhere the central bolt of a pulley or демпфера (depending on engine type) with the help накидного a wrench. To turn a cranked shaft accordingly on 1/3 turns. To turn off a heat-shielding of the multipurpose switch. To remove the tip on case AKP. After that to remove from loops тросодержатели systems procon-ten and to wring out cables upward. To turn off a forward arm of the engine. To raise АКП by means of a garage jack and to weaken bolts of fastening АКП. The engine connected with АКП, slightly to overturn back; after that again to bring under the engine a strong support. To turn off шестигранный a bolt of a rezino-metal support of arm АКП behind. To turn out the bottom connecting bolts, fastening АКП to the engine. To wring out АКП from the engine; if necessary to take advantage of mount. Cautiously to lower АКП. At removal АКП to wring out the hydrotransformer. The hydrotransformer should remain together with АКП! Watch closely that it has not dropped out (to fasten a wire).

Installation of an automatic transmission

Installation occurs in the logic image in return sequence in comparison to removal. The special attention is deserved by following moments:


    To check, whether it is correct in АКП the hydrotransformer is established. To watch that at installation it has not moved forward. For hydrotransformer fastening to a flywheel it is necessary to use original bolts, differently the hydrotransformer it will be destroyed. At installation in last turn to twirl bolts of a rezino-metal support. Before it a support to correct so that the support core was in the case middle. To establish подкладную a washer in the thickness of 13 mm between a countersupport of a tube of system of cooling ATF and АКП. If necessary to fill in new ATF. To establish an exhaust pipe. To adjust the selector lever.

The moments of an inhaling of fastenings АКП

Primary shaft to АКПГидротрансформатор to маховикуАКП to the engine
Arm to АКП
Arm АКП to a body