Engine Control Unit (ECU) Coding

Hello everyone.
I need to install a used engine control unit (ECU) into a Golf 4 TDI on Monday.
Install a Bj 98 Mot control unit (part number AHF). Can anyone tell me how to proceed with the coding process?
You need to proceed using the VAG 1552.


Greetings, Marcello.

Hello Marcello,
What are the part numbers and software versions of the old and new control units?

Best regards, Rudi.

They are exactly the same!

Hello Marcello,

Assuming the old control unit is 'original,' it should work as follows:

Replace the engine control unit (ECU) MSA15.
After installing a new engine control unit.
The following work steps must be carried out:
1. Perform the coding of the new engine control unit.
2. Adjust the immobilizer system to the engine control unit.
3. For vehicles equipped with a speed control system (recognizable by the switch on the steering column), this system must be activated in the engine control unit.
4. If necessary, check and clear the error memory.

Perform the coding of the new engine control unit.
Connect the VAG tester, either model 1551 or 1552.
· Insert the ignition key into position 2 (but do not start the engine).
· Input 01 (motor control)
· Input 07 (Code the control unit)
· Enter 00001 (automatic transmission) or 00002 (manual transmission).

Adjust the drive-away protection system to the engine control unit.
Connect the VAG tester, either model 1551 or 1552.
· Insert the ignition key into position 2 (but do not start the engine).
· Input 25 (immobilizer)
· Input 10 (Adjustment)
· Input 00 (Channel 0)
· Acknowledge the prompt 'Delete learning values' with the key 'Q'.
· Adjustments are completed by pressing the '->' button.
· Turn off the ignition.

Upon the next ignition start, the engine control unit (ECU) identification code is read by the immobilizer control unit.
Activate speed control system.
Connect the VAG tester, either model 1551 or 1552.
· Insert the ignition key into position 2 (but do not start the engine).
· Input 01 (motor control)
· Input 11 (Login procedure)
· Input 11463 (Deactivated 16167)


Best regards, Rudi.

Okay, Rudi, I'll try it tomorrow.

Thank you very much!