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.


J126_4L_87_____1_0707_21_Funktion.htm
J126_4L_87_____1_1105_21_Funktion.htm
J151_4L_24_BAR_2_1005_21_Relaistraeger.htm
J245_4L_60_____1_0405_21.htm
J271_4L_20_BAR_1_0905_21.htm
J271_4L_24_BAR_1_0905_21_Sicherungen.htm
J271_4L_24_BHK_1_0706_21.htm
J293_4L_19_BAR_1_0306_21.htm
J338_4L_23_BTR_1_0407_21.htm
J338_4L_23_CASA_1_1107_21.htm
J338_4L_24_BAR_1_0905.htm
J392_4L_60_____1_0405_21.htm
J394_4L_60_____1_0405_21.htm
J694_4L_97_____1_1205_21_Relais_Spannung_KL_75X.htm
J843_4L_57_____1_1107_21_Codierung.htm
J844_4L_96_____1_0608_21_Anpassung.htm
J880_4L_26_CATA_1_1108_21.htm

Fresh air blower control unit - J126

 

A - Fixing screws

B - Connector to Climatronic control unit -J255

C - Connector to fresh air blower -V2

D - Fresh air blower control unit -J126

 

The fresh air blower control unit -J126 is located immediately next to the fresh air blower -V2 and is accessible via the cover in the plenum chamber.

It controls the blower -V2 and the communication with the Climatronic control unit -J255.

 

Measured value block 045

 

Display zone 1

 

Climatronic control unit -J255 calculated actual voltage at fresh air blower -V2- in V (Volts).

Display zone 2

 

Climatronic control unit -J255 calculated specified voltage at fresh air blower -V2- in V (Volts).

 

Display zone 3

 

Activation of fresh air blower -V2 calculated by -J255 as percent of maximum possible activation.

The activation is over a data wire (activation wire) directly to the blower control unit -J126.

Readout = 0 ....5 percent

Fresh air blower -V2 off

Readout = 5 ...0.100 percent

Fresh air blower -V2 in loop control mode.

 

Display zone 4

 

Actual voltage measured by Climatronic control unit -J255 at fresh air blower -V2- in V.

 

Measured value block 046

 

Display zone 1

 

Actual current flowing via fresh air blower -V2

The value for the current flowing via the fresh air blower -V2 is regulated by the

fresh air blower -J126 and transmitted to the Climatronic control unit -J255.

J Readout = "0...XX A" (Amperes)

The current is regulated steplessly from  0 to around 25 A .

 

Display zone 2

 

Currently not used

 

Display zone 3

 

Voltage measured during basic setting for the fresh air blower -V2 at the lower measuring point in V at 35% blower speed.

 

Display zone 4

 

Voltage measured during basic setting for the fresh air blower -V2 at the upper measuring point in V at 70% blower speed.

 

YZ Note:

J Different versions exist for vehicles with and without auxiliary/additional heater.

J From 11.2007, for vehicles with a comfort air conditioner a modified fresh air blower control unit -J126, a modified Climatronic control unit -J255 comfort version and a modified fresh air blower -V2 will be phased-in. Ensure correct assignment of these components.

J Up to 11.2007, on vehicles with air conditioner - regardless of version - a fresh air blower control unit -J126 with part number 7L0 907 521(see illustration), a fresh air blower -V2 with part number 7L0 820 021 with differing indexing and a Climatronic control unit -J255 with part number 4L0 820 043 up to index J were fitted.

J From 11.2007, on vehicles with a comfort air conditioner a fresh air blower control unit -J126 with part number 3C0 907 521 as from index B, a fresh air blower -V2 with part number 4LX 820 021 with differing indexing and a Climatronic control unit -J255 with part number 4L0 820 043 as from index K will be phased-in. There is no change in respect of basic version air conditioners. Ensure correct assignment when replacing one of these components.

 

Site news

November 30, 2012
Content update We are starting big site update. We are sorry for bugs and missed content.
We are especially grateful for financial support of our site

User Name
Password
Forgot your password?
Register
Яндекс.Метрика