ECU - Electronic Control Unit

In terminology of VW-group it's any electronic device, which has been carried out some logic function. Sometimes it looks like nonsens - even simple relay can be called ECU.

The coding of Electronic Control Unit used for explain the ECU where it is and what "neighbours" does it have. Very often on modern cars the coding is crossed with adaptation.

Adaptation of the Electronic Control Unit serves to explain to the ECU with whom and how to talk (If we have started to speak allegories) and serves as storehouse of various adjustable parameters. ( part of memory in the Control Unit which can be changed via internal software )

Measured Values Blocks ( MWB ) – various parameters being inbound or calculated. Considering to value of MWB Electronic Control Unit, trying to "control"... Using of MWB allows you ( if you know the basic parameters ) to find out "close to boundary" or temporarily arising ( intermittent, sporadic ) malfunctions and many other useful things at competent use.


The following deals with replacement of the mechatronics unit - that is, the valve body and control unit:



The new mechatronics unit is supplied complete with flashed software and a parameter set matching the vehicle. The adaption values for clutch calibration are in their default settings (predefined value).


After replacing the mechatronics unit a complete basic calibration of the gearbox is necessary, so a basic setting  should be carried out.


Position sensors / synchronous body position:

The position sensor calibration is begun by selecting channel 61. Once the end positions have been calibrated (pay attention to readout!), the next calibration follows.

Selecting channel 60 initiates the next calibration - of the synchronous body positions (synchronous points). Only when these two calibrations (channels 61 and 60) have been successfully completed is the basic calibration classified as passed.


Clutch adaption: (clutch safety function, main pressure)

Software version < 0800: Clutch setting with selection of channel 62. The setting is made just low enough so that no torque is transmitted.

Software version >= 0800: A clutch adaption at standstill is not necessary here, though rapid adaption needs to be initiated by selecting channel 67 (sets the adaption values to predefined values).


As generally nothing is known of the history of the new mechatronics unit, the values of the clutch safety function are reset by selecting channel 68.


Also, the values for automatic main pressure adaption should be reset to their default values (predefined values). This is done by selecting channel 65.


The adaption itself is carried out later automatically during driving.


Fitting info:

The fitting of steering wheel paddles is checked and stored by the gearbox control unit. If a new control unit is fitted, it is necessary to select channel 63 in order to reset this fitting information to "not recognised". This initiates the procedure for recognition of the steering wheel paddles, and a corresponding entry is made permanently in the fitting information. The same principle applies to detection of the ESP and touch-control cruise control variants fitted in the vehicle. This information is reset by selecting channel 69.


Error memory:

At the very end of the test procedure, if passed successfully, the fault memory should be erased. If failed, its contents should be saved.  


Defined adaption test drive:

Recommendation for a test drive and further checks after replacing the mechatronics and successfully performing basic setting.

Preconditions: Gearbox temperature > 30°C < 100° C

J Drive in Tiptronic from standing start up to 6th gear. Drive repeatedly in each of 3rd, 4th ,5th and 6th gears for at least 2 minutes under constant load.

J Engine speed window for all gears 1500 - 3000 rpm.

J Perform 1 sharp braking followed by full-throttle acceleration (to check oil return)

J Manoeuvring with assessment of creepage and starting-off

J Check for leaks

If the test drive cannot be undertaken in the way recommended or for the period recommended, the fast adaptations still outstanding are undertaken automatically and unnoticeably in the subsequent driving cycles.


Summary of actions

1. Channel 61 - Calibrate gearbox tolerances (Engaged calibration)

2. Channel 60 – Calibrating the gearbox tolerances with reference to the position of the gear selector       (measurement of synchronising point)


3a) Software version < 0800 à Channel 62 - Calibration of clutch adaption at standstill

3b) Software version >= 0800 à Channel 67 - The values for the clutch adaption are reset.


4) Channel 68 - Reset values for clutch safety function

5. Channel 65 - Reset values for automatic main pressure adaption to defaults

6. Channel 63 - Reset "Steering wheel paddles" fitting info to "not recognised"

7. Channel 69 - Reset "ESP and TouchCCS" fitting info to "not recognised"

8. Interrogate fault memory and erase if test passed

9. Defined test drive




CCS - Cruise control system

ESP - Electronic Stability Program


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