Automatic transmission provides selection of necessary transfer number according to mechanical, hydraulic and electronic the influences submitted on the unit. Certain types of repair are beyond the real management. In this section typical malfunctions which can be eliminated independently are considered.

The self-diagnostics payment in the block of electronic control provides tracking of normal parameters of work of transmission, finds the parameters leaving out of established limits, brings the found refusals in memory and stores information for the subsequent viewing. The majority of the electronic products which are a part of the electronic control unit by automatic transmission can be checked by means of testing of conclusions of the socket of this block. At specialized service stations the special electronic equipment is applied to reading and a conclusion to the screen of information containing in memory of refusals. Quicker to establish a cause of defect and to execute repair expediently to present the car to experts who can decipher information containing in memory on refusals. If necessary address in service of car-care center of the local proxy dealer of "Volkswagen".

Level of transmission liquid

Pay attention to a condition of transmission liquid. Check of level of liquid and its condition should be the first action by search of malfunctions.

Sometimes seeming serious malfunction of automatic transmission can eliminate only with a method of restoration of level of transmission liquid. Liquid level strongly depends on temperature therefore importance has observance of conditions of measurement.

PREVENTION Liquid filling above normal level is not allowed. Excess of liquid can become the reason of abnormal work of transmission.

If level of liquid is much lower than norm, it is necessary to examine a case of transmission and to check it on existence of external damages. Attentively check existence on the places of all details of fastening and their inhaling, and also pay attention to possible traces of leaks. If leaks outside it is not revealed, violation of internal consolidation of a compartment of the main transfer that leads to substantial increase of level of oil can be the reason of fall of level of transmission liquid.

Liquid condition

Check of a condition of liquid is carried out visually. At a normal mode of operation red color of fresh liquid strongly darkens that is not a reason for its immediate replacement.

The caustic, "burned" smell of liquid indicates its overheat therefore chemical decomposition begins. The reason for that can be or low level of liquid, or, as in more difficult case, abnormal operation of hydrocouplings of coupling and brake mechanisms.

The dirty or "dairy" type of liquid indicates hit in it of water or cooling liquid owing to malfunction of a cooler. Also it is possible to carry a leaky prileganiye of the index of level of transmission liquid or its absence to the most probable causes.

Long work of transmission with dirty or poor-quality liquid can lead to destruction of hydrocouplings and brakes. For replacement merge liquid, clear the pallet, replace the filter and fill in pure liquid.

Check of level of oil in the main transfer

In a compartment of the main transfer the gipoidny oil providing sufficient greasing on all service life is filled in. Change of oil is not required. To check level of oil there is no need except for leaks or any other reasons suggesting that level of oil is lower than norm.

Fig. 8.80. The roller of a drive of a speedometer also can serve and for definition of level of oil in the main transfer. Insert into place the pure roller, level of oil should be between the arrows "Min" and "Makh" (the difference between these levels corresponds 0,1 l)

In the main transfer it is possible to judge oil level on availability of greasing on a gear wheel of a drive of a speedometer. For check of level disconnect a cable of a drive of a speedometer in a back top part of the case of the main transfer and get the roller of a drive of a speedometer. Wipe the roller and insert back to check level on a greasing trace (fig. 8.80) .

Check of frequency of rotation of a cranked shaft of the engine at full loading

These tests allow to check a condition of the hydrotransformer and planetary transfer when other obvious reasons of abnormal work are absent. Tests are senseless for carrying out in the presence of signs of malfunction of the engine. The exact tachometer as tachometer indications on the dashboard are insufficiently exact is necessary for measurement of frequency of rotation.

Carrying out tests

Carrying out tests carry out in the following order:

start up the engine for some minutes for warming up it and transmissions to normal working temperature;

switch off ignition, connect a tachometer and arrange it so that it was possible to read out indications from a seat of the driver. To connect a tachometer follows according to the instruction of the manufacturer;

again start up the engine. Put the car on the hand brake and to the full press a brake pedal to provide motionless position of the car;

to establish the selector lever in situation D;

PREVENTION Term of behavior of test should be as it is possible more shortly — test should be finished at once after reading of the indication of a tachometer. Limiting time of tests — 5 pages. If it is necessary to carry out the following test, from the moment of carrying out of the first prior to the beginning of the second should pass not less than 20 pages.

NOTE The result should be 2700 mines-1. Reduction of frequency of rotation approximately on 125 mines-1 on each 1000 m above sea level is allowed. At high temperature of air frequency of rotation also should decrease.

holding the car brakes, press an accelerator pedal before complete opening of a butterfly valve, having read thus the tachometer instrument. The number of turns of the engine should increase, and then remain constant at loading influence.

If frequency of rotation on some hundred turns is lower, reduction of traction qualities of the engine can be the reason. Too high frequency of rotation testifies to malfunction of the hydrotransformer and planetary transfer.