Audi Workshop Service and Repair Manuals

Notes:

• ◆ A 5-character code must always be displayed during the control unit identification.
• ◆ The control unit must be re-coded as follows if the tester does not show the correct code for the vehicle, or if the control unit has been renewed.

Special tools, workshop equipment, testers, measuring instruments and auxiliary items required

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

Work sequence

• ‒ 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
  .)

• ‒ Press keys 0 and 7 for the function "Code control unit" and confirm entry with Q key.

• ‒ Enter the relevant code number for this vehicle and confirm with Q key.

• Coding variants => Page 24-131.

• ‒ Press the ⇒key.
• ‒ Press keys 0 and 6 for the "End output" function and confirm input with the Q key.
• ‒ Switch off ignition.

Note:

The code unit entered and shown on the display will not be used by the engine control unit until the ignition has been switched off once.

An incorrect coding leads to:

• ◆ Engine running faults (gear change jerks, load change jerks, etc.)
• ◆ Increased fuel consumption
• ◆ Increased exhaust gas emissions
• ◆ Faults stored in fault memory which are not actually present
• ◆ Functions will not be performed (Lambda regulation, activation of the activated charcoal filter system, etc.).
• ◆ On front wheel drive vehicles the traction control will not function (TC warning lamp comes on)
• ◆ Reduced gearbox life