Automatic transmission provides selection of necessary transfer number according to the mechanical, hydraulic and electronic influences given on the unit. Certain types of repair are beyond the present manual. 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 going beyond the set 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 an electronic control unit 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 used to reading and a conclusion to the screen of information on refusals which is contained in memory. Quicker to establish a cause of defect and to execute repair expediently to present the car to experts who will be able to decipher information on refusals which is contained in memory. If necessary address to service of car service of the local authorized dealer "Volkswagen".

Level of transmission liquid

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

Sometimes the malfunctions of automatic transmission seeming serious can be eliminated only with method of restoration of level of transmission liquid. Liquid level strongly depends on temperature therefore observance of conditions of measurement is important.

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

If the level of liquid is much lower than norm, it is necessary to examine a case of transmission and to check it for 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 are not revealed, violation of internal consolidation of a compartment of the main transfer can be the cause of lowering of the level of transmission liquid that leads to substantial increase of level of oil.

Condition of liquid

An inspection of a condition of liquid is carried out visually. At the 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. Can be the reason for that or the low level of liquid, or, as in more difficult case, abnormal work of hydraulic clutches 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 low-quality liquid can lead to destruction of hydraulic clutches 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 lubricant on all service life is filled in. Change of oil is not required. To check the level of oil there is no need except for leaks or any other reasons suggesting that the level of oil is lower than norm.

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

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

Check of frequency of rotation of a bent 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. It is senseless to carry out tests in the presence of signs of malfunction of the engine. The exact tachometer as indications of a tachometer on the dashboard are insufficiently exact is necessary for measurement of frequency of rotation.

Carrying out tests

You carry out carrying out tests in the following order:

launch the engine for several minutes for warming up it and transmission up to the normal working temperature;

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

again launch the engine. Put the car on the emergency brake and to the full press a brake pedal to provide motionless position of the car;

to install the selector lever in situation D;

PREVENTION The term of behavior of test has to be as it is possible well — test should be finished at once after reading of the indication of a tachometer. Limit time of tests — 5 pages. If it is necessary to carry out the following test, then from the moment of carrying out the first prior to the beginning of the second there have to pass not less than 20 pages.

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

holding the car brakes, press an accelerator pedal before full opening of a butterfly valve, having read at the same time the instrument of a tachometer. Speed of the engine has to increase, and then remain constant at influence of loading.

If rotation frequency on several hundreds of turns is lower, then reduction of traction qualities of the engine can be the cause. Too high frequency of rotation testifies to malfunction of the hydrotransformer and planetary transfer.