Audi A4

Since 1994 of release

Repair and car operation

Audi А4
+ Running gear
+ Regular servicing
+ Engines
+ Turbo-supercharging
+ Exhaust system
+ Cooling system
+ Fuel tank and the fuel pump
+ The air filter and channels всасывания
+ Injection system
+ Coupling
- Transmission and the main transfer
   Mechanical transmission
   Noise in a transmission
   Automatic transmission
   Electronic control by a transmission
   The main transfer
   Power shafts
   Check of cuffs of power shafts
   The help at malfunctions
+ Suspension bracket of wheels and steering
+ Brakes
+ Wheels and tyres
+ The electrotechnical equipment
+ Ignition system
+ Illumination
+ The alarm equipment
+ Tools and devices
+ Heating and ventilation
+ Body details
+ Salon
Search of malfunctions
Technical characteristics

Electronic control by a transmission

In planetary transfer all gear wheels are constantly linked. Various steps of transfer are reached without rupture of draught by a starting or keeping of a solar wheel, planetary gear wheels or a ring gear wheel of planetary transfer.
1 – the details set in motion;
2 – kept details.

Entrance signals

In the electronic block of management the information arrives from:

  • The lever-selector with the multipurpose switch of position. Lever installation inclusion of lanterns of a backing, the blocking mechanism of a starter copes at the included range of change of transfers, and also inclusion/deenergizing of the device of adjustment of speed;
  • Potentiometer throttle заслонки about its position. It is the knot known on injection, serves for calculation of points of a gear change;
  • The gauge of speed in a transmission for definition of speed of movement, and also gear change points. If this gauge is faulty, the signal from the Hall gauge undertakes;
  • The gauge about number of turns on a transmission input. Also settles down on a transmission and serves for definition of points of a gear change;
  • The accelerator gauge in a cable throttle заслонки; it gives a signal when the gas pedal is completely wrung out. After that there is a switching on higher transfer or if it is necessary, there is a switching downwards on one or two ranges of change of transfer number;
  • The switch of brake fires for разблокирования electromagnetic blocking of the lever-selector. The Lever-selector moves from position Р or N in one of ranges of change of transfer number only at the pressed pedal of a brake;
  • The gauge of temperature ATF in a transmission. When in the block of management of the engine the signal the raised temperature arrives, in separate ranges of change of transfer number there is a switching on higher level. It reduces a backlash in the hydrotransformer and reduces temperature ATF – only after that there is a switching on the standard program.

Management of gear change process

If you move the lever-selector to position D, ATF, being under pressure, arrives in so-called switching заслонки in a box which in turn operate in the hydraulic way lamellar couplings and brakes. The management block regulates pressure by means of electromagnetic valves and, in such a way, defines the switching moment on higher or low transfer, and also switching transitions. Simultaneously there is a communication with the block of management of ignition/injection – at switching on higher transfer the ignition moment is slightly removed that switching proceeded softly.

Signals from the management block arrive further to an electromagnet of blocking of the lever-selector, the combined relay of blocking of a starter and to backing lanterns. If Audi A4 it is supplied by system of adjustment of speed the block of management submits transmission automatics on it pressure only when the range of change of transfer number of forward transfer is included and speed of 30 km/h is for the first time exceeded.


The block of management of an electronic transmission can distinguish arising defects and to keep them in the computer. Arising failures are remembered in a long-term memory. The memory can be interrogated in a workshop. It becomes by means of the reading out device; unfortunately, possibility for interrogation of the computer by the fan is not provided. If you assume malfunction presence in management of a transmission consider memory of the computer you can only in workshop Audi.

Emergency course

4-step АКП

If the management block has distinguished defect which essential negative impact on functioning makes, or the block of management is faulty, the mode of "an emergency course joins. For this purpose there are two emergency programs:

  • If the lever-selector is in position D, 3 or 2, the transmission a hydraulic way includes 3rd transfer. The chosen range of change of transfer number joins only in positions of the lever-selector 1 and R.
  • If the signal about number of turns of the engine and speed does not arrive also pressing of a pedal of an accelerator for the first time exceeds value ѕ, the transmission is switched to a step N, i.e. There is no drive more. By deenergizing of ignition and new start of the engine you can try to make active a transmission again.

Emergency course

Transmission 5-NR-18

The transmission has different modes of an emergency course depending on character of malfunction:

  • At insignificant failure movement is carried out on other program of a gear change.
  • At defect in a mechanical part of knot of a gear change during movement the transmission remains included on 4th step. Then after engine deenergizing 3rd range of change of transfer number joins just.

Check of an automatic transmission

The automatic transmission practically does not leave to the fan of possibilities for its initiative. But purposeful check will help to localise malfunction that not in the last instance is of interest at purchase of the second-hand car:

  • In the presence of malfunction first of all check up level ATF in a transmission.
  • If ATF on probeе for its measurement smells burnt there is a heavy damage of a transmission. In this case brake tapes or coupling plates can be defective.
  • At a trial trip you can check up gear change points.
  • How there is a gear change process, gives the information on a transmission condition.
  • Adjustment of a cable throttle заслонки with the integrated mechanism of switching by sharp pressing of a pedal of gas is the important condition of a faultless operating mode.
  • The same concerns adjustment of a cable of the lever-selector.

Estimation of process of a gear change

During a trial trip you can pay the attention to gear change process:

Switching on higher transfer: at partially wrung out pedal of gas transfer change almost is not felt; at full gas or sharp pressing a pedal of gas transitions become more distinct, but higher transfer should seize always softly. Short increase of frequency of rotation of the engine at transfer change specifies in defect which should be studied more attentively.

Switching on lower transfer: without gas (at качении) it is hardly notable on very low speeds. The push at switching on a backing on partial or full gas is normal. Return switching without gas the lever-selector lasts one-two seconds. If at compulsory switching back the lever-selector gas the gear change occurs without delay simultaneously increases.

 Council: Cars with an automatic transmission cannot be towed on the distance exceeding 50 km, otherwise it will appear a transmission insufficient greasing. For the same reason speed of movement should not exceed 50 km/h. At towage the lever-selector should be in position N. In a doubtful case choose more convenient way and ship the car.