Volkswagen Workshop Service and Repair Manuals

The engine control unit regulates the injection, throttle valve control part, Lambda regulation, ignition, knock control, activated charcoal filter solenoid valve 1, speed regulation via injectors or fuel pump relay, camshaft adjustment and self-diagnosis.

Special tools, testers, measuring instruments and auxiliary items required

• ◆ Fault reader V.A.G 1551 with cable V.A.G 1551/3

Work sequence

• ‒ First print out the control unit identification and thereby the previous control unit coding as follows:
• ‒ Connect the fault reader V.A.G 1551 (V.A.G 1552). Then switch ignition on and select engine control unit with the "Address word" 01.
  (Connecting fault reader and selecting engine control unit .)

• ‒ Print out the control unit identification by pressing the fault reader print button.
• ‒ Press the ⇒key.
• ‒ Press keys 0 and 6 for the function "End output" and confirm entry with the Q key.

• ‒ Switch off ignition.

• ‒ Remove the old control unit and insert the new one.
• ‒ Check the previous coding and the coding of the new control unit => Page 24-114
• ‒ Match new control unit to the electronic immobilizer => Page 24-119
• ‒ Match new control unit to throttle valve control part => Page 24-116
• ‒ Then subsequently interrogate the fault memory of the new engine control unit and erase the fault memory if necessary.