A6 C4 TDI Engine Control Unit

Hello.

I have a question.

When replacing the engine control unit (ECU) on a Volkswagen A6 C4 2.5 TDI with the AEL engine, are there any issues with the immobilizer system, or is there a separate control unit for that?

Hi,

There are generally no problems.
The WFS is included in the MSG. You need to set the corresponding value in the MSG to 0 using VAG-COM and then start the engine.
Please don't be upset if I don't describe the adaptation in more detail. I'm not sure if that's something that's well-received here, and I don't want to overstep any boundaries.
But you should be able to find out by searching.
Otherwise, someone from the decision-making team here could just send me a quick "OK" via private message. Then I'll email you and explain how it works.

Best regards,
Wool.

No, adjusting the WFS is not something that can be easily done, unlike deactivating it.
http://wiki.ross-tech.com/index.php/Diagnostic_Procedures (Immobilizer)

Thank you for the quick responses. But I have one more question. Does the control unit need to be installed beforehand, or can I take the control unit to the Audi dealership and then simply replace the old one in the car afterwards?

Built-in.