SEAT Workshop Service and Repair Manuals > Leon Mk2 > Power unit | 4LV Injection and Ignition System | Mixture preparation system, electronic inj.,Gas | Engine control unit

Engine control unit renew

Special tools and workshop equipment required

t	Fault reader -V.A.G 1551- with cable -V.A.G 1551/3B-

Work sequence

–	First print out the control unit identification and thereby the previous control unit coding as follows:

–	Connect fault reader -V.A.G 1551/V.A.G 1552-. Switch ignition on and select engine control unit with the “Address code” 01. (Fault reader: Connecting and selecting the engine control unit → Chapter).

The control unit identification and the coding will appear on the display, e.g.:

–	Print out the control unit identification by pressing the fault reader print button.

–	Press → -key.

–	Press keys 0 and 6 for the “End output” function and confirm input with the Q -key.

6K0906034A  MARELLI 4LV      S121    ->

Coding XXXXX                   WSC XXXXX

Indicated on display:

–	Switch off ignition.

–	Unlock the engine control unit connector and pull it off.

Rapid data transfer                 HELP

Select function XX

–	Carefully lever off the retaining tab with a screwdriver -arrow-.

–	Unclip the control unit from the retaining frame -arrow-.

–	Place the new control unit into the retaining frame and fit tab back in original position.

–	Install control unit connector and lock.

–	Check the previous coding and code the new control unit → Chapter.

–	Adapt new control unit to throttle valve control part → Chapter.

–	Adapt new engine control unit to electronic immobilizer → Chapter.

–	Adapt exhaust gas recirculation potentiometer, proceeding as follows:

Indicated on display:

–	Press keys 0 and 4 for the function “Introduction of basic setting” and confirm entry with Q -key.

Rapid data transfer                 HELP

Select function XX

Indicated on display:

–	Press keys 0, 7 and 4 for “Display group number 74” and confirm entry with Q -key.

Basic setting                       HELP

Input display group number XXX

Indicated on display: (1...4 = Display fields)

–	Check value in display field 4.

(digit from left)

Specification: ADP. OK

–	Conclude adaptation by pressing → -key.

–	Then subsequently interrogate the fault memory of the new engine control unit and erase the fault memory if necessary.

–	Carry out idling check → Chapter.

System in basic setting  74           ->

      xxx %      xxx %     x     ADP. ON

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